Good evening.
Tonight we're gathered for the
last Longwood Seminar of 2019.
So welcome I'm Gina Vild.
I'm the Associate Dean for
Communications and External
Relations at Harvard
Medical School.
And I'm just delighted to see
so many people here tonight.
And tonight we're going to talk
about sleep and why it matters.
And I know for certain that
this is an important issue
and concern for all
of us because it
is the most frequently requested
topic of the Longwood Seminars
each year.
And so we're really thrilled
we were able to put together
three of Harvard's
leading experts
to talk to you about it tonight.
The topic affects
all of us because we
know that without sleep,
our body and mind are not
at their best.
So raise your hand
if you feel you
need more sleep in your life.
We why you're here.
So tonight you're going to learn
how to sleep better and sleep
longer.
And so I wanted to
first thank all of you
who attended this year both in
person and on our live stream.
So if you've attended all
four seminars, this year,
would you please
raise your hand?
OK, fabulous, so I think
we need to give all of you
round of applause.
[APPLAUSE]
And I also would like to
applaud those who are watching
through the Livestream.
You're among the
46,000 people who
joined us and have been in
this classroom this year
for the first three seminars.
So that's quite impressive.
So in addition to those
of you here in Boston,
we have had
individuals joining us
from around the world--
from England, Canada, India,
Australia, Brazil,
Turkey, Pakistan, South
Korea, and Egypt, among
many other countries.
So this is truly an
international event
that you're a part of.
And if you've missed any
of the seminars this year
or past years, we invite you
to watch them on our Harvard
Medical School website.
So before we begin, I'd like to
thank two members of our team
tonight.
First, Lauren Gustafson,
who make sure these seminars
are available to you
through our social media.
And she's the one
on the Livestream
who's prodding you
to ask questions.
She's in the booth.
So she's not down in the front.
But I want to thank her
in particular because it's
her birthday tonight.
And she chose to be with us.
[APPLAUSE]
Happy birthday,
Lauren, and thank you.
And I'd also like to
thank Barbara Lynn--
Barb, would you come up please?
Many of you may know Barb
from having inquiries
about the Longwood Seminars.
But she is the leader
of this program.
And you may not realize that
but her work for 2020 starts
tomorrow.
So she's going to be
starting to organize
the next seminars tomorrow.
And she's done an
extraordinary job this year.
And so, Barbara, I
want to thank you
for your hard work, ingenuity,
and for your passion
for the Longwood Seminars.
And so tomorrow Barbara's
going to send you an email,
and I hope all of
you will open it.
It's a survey that
will help us improve
this program for future
years and for next year
in particular.
And one of the questions
we're going to ask you
is what topics you would
like to see us feature.
And we take these
suggestions very seriously,
and we crowdsource the topics
for the mini Med school.
So please take
minutes-- that's all it
will take to answer the survey.
And if you're watching
through the Livestream,
we invite your feedback as well.
So this is the link
for the survey--
bit.ly/LWS_survey.
And please take a
minute and tell us
what you would like to see and
tell us how we did this year.
So just a couple
more announcements.
If you would like additional
resources on sleep health
or other health related topics,
please visit Harvard Health
Publishing's website--
www.health.harvard.edu.
And this is where you're
going to find a special health
report on how to improve sleep.
And for those of you who
are students of the Longwood
seminar, it's being
offered as a discount
if you use the code HMSLS.
We offer certificates
for those who
attend three or more seminars.
So I'm told already
a hundred people
have earned certificates.
And after tonight, another 200
individuals will also qualify.
So I am truly awed
by your commitment.
And I honor your achievement.
Thank you for being a
part of this program.
If you've attended the
first three seminars,
you can pick up your certificate
in the table in the back.
For those who qualify tonight,
we will be sending those to you
by mail or email.
And also if you
are a teacher, we
offer professional development
points for our teachers
and we've had many
teachers join us this year.
We will be mailing those
professional development
points in the coming weeks.
As you know because
so many of you
have been here to pass seminars,
we take your questions.
And we try to get to as
many of them as we can.
So our staff will be walking
up and down the aisles.
Please, pass your question
to a member of our team.
And if you're watching
through the Livestream,
Lauren is going to ask you
to please post your question
and note the country from which
you're watching in the comments
section of YouTube or Facebook.
And we get to as many of
those questions as possible.
And so for the final
time this year, I'm
going to ask you to turn down
your phone, silence them,
and but do not turn them
off because we're hoping you
will join us for a Twitter
conversation at #HMSminimed.
So now to our program.
Here's what you may
or may not know.
About 70% of people
get insufficient sleep
and are sleep deprived.
And this audience
is representative I
think from the show of
hands for this statistic.
1/3 sleep six hours
or less, doubled
the rate from 50 years ago.
So the world is moving faster.
We are running to keep up.
And as a result,
we're sleeping less.
An estimated 50 to
70 million Americans
suffer from chronic
sleep disorders.
The Centers for Disease
Control and Prevention
recently declared
sleep disorders
to be a public health epidemic.
And research has found
that lack of sleep
reduces our ability to
concentrate, think logically,
and to remember.
So it's a very serious concern.
And for that
reason, we're really
thrilled to have three
of Harvard's top experts
on sleep health.
First, I'd like to
introduce Dr. Judith Owens.
She is the professor of
neurology at Harvard Medical
School and serves as the
Director of Sleep Medicine
at Boston Children's Hospital.
Dr. Robert Stickgold is
an associate professor
of psychiatry and the center
for sleep and cognition
at Harvard Medical School and
Beth Israel Deaconess Medical
Center.
And, first, you'll hear from
our moderator, Dr. Charles
Czeisler.
Dr. Czeisler is the Frank
Baldino junior professor
of sleep medicine and
director of the division
of sleep medicine at
Harvard Medical School.
He is chief of the division
of sleep and circadian
disorders in the departments
of medicine and neurology
at Brigham and Women's Hospital.
And he is a nationally
recognized expert
on sleep medicine.
So thank you for joining
us and please join me
in welcoming our
speakers tonight.
[APPLAUSE]
Thank you so much, Gina.
And thank you for to Ms. Berlin
for organizing all of this.
It's really exciting to be here.
I'm going to encourage
Dean Vild and Ms. Berlin,
as you're planning
next year's program,
to remember that we do spend
a third of our lives asleep.
So I hope you spend a
third of the program
on something related to
sleep in future years.
So as Dean Vild
mentioned we are really
experiencing an
epidemic of sleep
deficiency in our society.
And she mentions
how many people are
suffering from sleep disorders
and insufficient sleep.
And it's really causing problems
at all ages in our society.
For example, children,
over the last century,
each year they get about 1
and 1/2 minutes less sleep
compared to the previous year.
So today they're getting
about two hours less sleep
in the United States per night
than they did a century ago.
Now, it's very unlikely that
during that time period,
we have somehow evolved to need
two hours less sleep per night
for those kids.
And so we're carrying
around at all ages
this burden of sleep deficiency.
And it affects us
in many, many ways.
One of the things
that I like to think
about as a barometer
of how sleep deprived
we are as a society is
just how many people
are struggling to stay
awake when they are driving.
So every month, about
56 million Americans
admit that they're having
difficulty staying awake
when they're driving.
About 8 million of them
lose that drug on actually
fall asleep at the wheel.
And then that causes about a
million crashes every year,
500,000 injuries every year,
and about 55,000 of those
are debilitating
injuries that leave
people either quadriplegic or
seriously injured in some way.
And it causes nearly
7,000 deaths every year.
In fact, one out of
every five car crashes
is related to sleep
deficiency in some way.
And so it really--
[MICROPHONE FEEDBACK]
It really represents a
very serious problem.
Maybe if I stand over here,
I'll be less problematic.
So the question is why is it
that we even need to sleep.
And sleep fulfills many
different functions
in the brain and in the body.
It fulfills basic
biological needs
in the brain in particular.
The brain uses more energy than
any other part of the body.
It's only 2% to 3% of
the weight of the body,
and yet it uses 20% to 30% of
all the energy that we use.
Professor Stickgold
is going to be talking
about the importance of sleep on
our ability to remember things,
on memory consolidation.
Sleep is also
critical for us to be
able to maintain our focus
and attention and alertness.
So that if kids don't
get enough sleep
before they come to
school during the daytime,
then they're not going to
be able to focus and pay
attention in class.
One of the reasons why there are
so many drowsy driving crashes
is that our ability to sustain
our attention at a task,
like a routine highly
overlearned task like driving,
is going to be greatly impaired
if we have not gotten the sleep
that we need beforehand.
So our reaction time
instead of being
a quarter of a
second, for example,
will be three or four
or five or six seconds.
And the average reaction time
will be three times longer
than it is if we are alert.
And so that can have
real consequences.
It can have consequences at all
different ends of the spectrum.
Athletes-- even top
professional athletes,
their reaction time
will be more sluggish.
And they will get fewer--
the basketball teams
will get fewer--
players will get
fewer free throws in,
the tennis players will
get fewer serves in,
and the runners will
not be as fast when they
haven't gotten enough sleep.
And also as Professor
Stickgold will talk about,
the different stages of sleep
are associated with the ability
to integrate what
we have learned
with what we knew
before and provides
a critical function for that.
But one of the other
functions of sleep
is as I mentioned there's
this furnace using
all of this energy in the
brain, and it is during sleep
that we replenish the
energy that we have used up
during the daytime.
And one of the
sensors that tells us
that the brain needs
more sleep is actually
located on cells in the brain.
And it represents as we
begin to use up the energy
and use up these
energy stores, then
some of the residual
parts of the energy
related molecules
build up in the brain.
And we start becoming
tired and the brain
starts being capable of making
an involuntary transition
from wakefulness to sleep.
And, of course, if that
happens when you're driving,
that can be very dangerous if
you're struggling to stay awake
and you lose that struggle.
And late Professor Bob
McCarley was the one
who discovered that it is
adenosine levels building up
in the brain that
actually make us sleepy.
And then, ironically,
what many of us
do in order to sort
of prevent that signal
from getting through
is we take caffeine
in one form or another.
And caffeine a blocker of
that receptor for adenosine.
So it doesn't
actually fulfill any
of the biological
need for sleep,
but it blocks the receptor.
So that so that we are
less likely to make
that transition involuntarily.
But it doesn't
prevent it altogether.
So think about that when you're
sort of waking up and saying
I can't function unless
I have a cup of coffee.
You would function better if you
actually got the sleep that you
need rather than papering over
that situation with something
that blocks the receptors.
It would be like taking--
instead of having
your furnace come
on when it's too
cold in the house,
you just put chewing
gum in the thermostat
so that you don't hear the
fact that the signal is not
transmitted that it's
getting cold in the room.
And, of course, if
that's the solution,
then that can lead to
burst pipes and all sorts
of other problems.
In the same way, in the brain,
if we don't get the sleep
that we need then
we can't fulfill
some of the key biological
functions of sleep.
And you can see the
changes in this diagram.
You remember that for
a while that "this
is your brain on drugs."
It was advertised
on TV all the time.
Well, this is your brain
without a night of sleep.
And you can see very
specific changes.
So this is energy utilization.
And you can see in the
area of the brain that's
responsible for judgment, you
can see that it is low on fuel.
And so it is getting
stoned cold there.
And that's one of
the reasons why
people who are not getting
the sleep that they need
are often exhibiting poor
judgment in the decisions
that they make.
Also, this is the
area of the brain that
relays sensory information
from our vision, touch,
and other senses to
other areas of the brain.
And this is the area that
receives visual information.
And we miss 10 times as many
signals in our visual field.
And that's one of
the reasons why
we have accidents when we're
driving because we don't even
see the things
that are happening.
So we are much more likely to
miss things that are happening.
That's why it's so
dangerous to have,
let's say, an air
traffic controller
who is responsible for seeing
the planes on the visual field
from a monitor,
because they're not
going to be able to
pick them up as readily.
And so this is one of the--
now, another really
key function of sleep
that has just only
recently been discovered
has been the clearing of
toxins from the brain.
So this high energy utilizing
organ, like any other--
like any anything else
that uses a lot of energy,
there are some byproducts,
metabolic byproducts of energy
that are essentially
debris in the brain.
It's kind of like in
your car, you begin
to build up sludge in the oil.
And you need to change the
oil and get the sludge out.
Well, in the brain, we
build up toxic metabolites,
like amyloid beta
and tau protein.
And if we don't
clear those out, they
can be toxic to
neurons in the brain.
And that's one of the things
that's associated with,
for example, Alzheimer's
disease is amyloid beta plaques.
And it is during sleep
that these newly discovered
lymphatic channels
actually expand and flush
out these toxins
when we are asleep.
And that that turns out to be
a critical function of sleep.
And once this was
discovered in 2012,
it began to make
people realize why
there was an association
with both sleep disorders
and with people with
insufficient sleep
with an increased
risk of Alzheimer's
disease and other
degenerative brain diseases.
So one of the key
functions of sleep
is to help you maintain
a healthy brain where
these toxins are cleared out.
Another key function
of sleep is--
and this has only been
recognized in the last 20 years
that sleep is not only
important for the brain,
but it's also critically
important for the body.
And so the cardiovascular
system depends on sleep.
It is during sleep
that the heart
is able to recover with
a lower blood pressure
and lower heart rate that
happens during sleep and repair
can take place during that time.
And people who don't get--
who sleep is either
interrupted or who
get an insufficient
amount of sleep,
they will begin to have
higher blood pressure.
And sleep disorders, like
sleep disordered breathing,
sleep apnea is the leading known
cause of high blood pressure.
And so anybody who is diagnosed
with high blood pressure
should have an
evaluation to find out
if they have sleep disordered
breathing, for example.
But even adolescents,
even teenagers,
if their sleep is disturbed
or fragmented or insufficient,
they will have higher blood
pressure than their peers.
So they are on the
road to hypertension.
And sleep also turns
out to be critically
important for our resilience
and our resistance to infection.
So the immune system is affected
by the sleep that we get.
So in the fall,
this past fall, we
were advised to get a flu shot.
And when people
get the flu shot,
if they haven't had an
adequate amount of sleep
in the week before
getting the flu shot,
they have only half the
antibody response than they have
if they are sufficiently
well rested.
Similarly, during
the winter, if you're
exposed to the rhino virus
that causes the common cold,
you'll have a 2% to
300% increased risk
of actually catching
a cold if you're
getting an insufficient
amount of sleep
or if your sleep is
fragmented and disturbed.
So consolidation of sleep,
getting a sufficient amount
of sleep are both important for
your immune system to function
effectively.
And that may be why--
that may be one of the reasons
why sleep fragmentation is
associated with an
increased risk of cancer
and an increased rate of
growth of cancer, tumors,
because the immune system
is being recognized
as playing more
and more important
role as we begin to understand
it in the prevention of cancer.
Now, sleep is also critical
for regulation of appetite.
People often talk
about the freshman 15,
which is sort of
the gain in weight
that occurs oftentimes
when kids start college.
And that gain in weight
may be associated
with the decreased
amount of sleep
that kids get when
they go to college.
You see somewhere during
evolution, sleep and appetite
got kind of linked.
And maybe that's because--
it's not fully understood
why that's the case,
but most other animals don't
sleep deprive themselves
spontaneously unless
they're starving.
And so the big cats, if they're
not getting enough food,
they will stay up for 24 or
48, even 72 hours on a hunt.
And during the time when they
sleep deprived themselves
in order to avoid
starving, their brain
goes into starvation mode
and releases more hormones
that make you feel hungry
and less of the hormones that
make us feel satisfied
with what we have eaten.
The problem is
that we voluntarily
sleep deprive ourselves when
we're not starving at all.
In fact, many times we have
the refrigerator right there.
And so we're sleep depriving
ourselves, watching
TV, watching a game, doing
this, working the night shift
or whatever we're
doing voluntarily,
and then we have a food
source right there.
So when we are having these
hormones being released
that make us more hungry
and less satisfied with what
we have eaten then we are
more likely to overeat
when we are sleep deprived.
And then people gain weight.
And then one of the
other amazing things
that happens when people
are sleep deprived
is that, in terms of metabolism,
the effectiveness of insulin
is reduced and
glucose levels go up
to a higher amount in
response to the same meal.
So now you have a situation
where people are gaining weight
and the response of the
metabolic system to food
is impaired.
And this puts many
people on and may
be contributing to the
epidemic of both obesity
and diabetes because of
these metabolic changes.
And because this increase
in obesity and diabetes
that have happened over
the last 20 to 40 years
have paralleled the
decrease in sleep duration
in our population
and the increased
problem with the epidemic
of sleep deficiency
in our society.
And amazingly enough, even
fat cells need to sleep.
So that if you biopsy
fat cells in people
who are well rested
and biopsy fat
cells from those same people
when they have been chronically
sleep deprived, the ability
of those cells to respond
and metabolize
glucose is actually
impaired from the
individuals-- if they've
been taken from individuals who
are chronically sleep deprived.
So the whole body is affected
when we don't get enough sleep.
And that's one of
the reasons why
I'm going to argue that
it's important to make
sleep a priority.
But it's not just the brain
and the body, but even
our emotions-- we become
much more volatile when
we haven't gotten enough sleep.
The risk of
depression increases,
the risk of suicidal ideation,
anxiety disorders increase.
Our ability to avoid
flying off the handle when
we are faced with an emotionally
challenging situation
becomes impaired
because-- and this
has been studied here at
the Harvard Medical School
by looking at brain scans.
The amygdala is a
region of the brain
that is responsible for
emotional responsiveness.
And so people in a scanner have
been shown disturbing images
and the reaction, the
response of the amygdala,
is 10 times greater
in individuals who've
missed a night of
sleep as compared
to those same individuals who
are more calm in their response
to these disturbing
images if they
have gotten sufficient
night of sleep beforehand.
So it sets up sort of a
perfect storm for situations
in which we would not really
want to place our children.
And so you can
imagine my surprise
when I was bringing out--
our daughters now 24 years old.
But when she was going to
pre-K, a couple of decades
ago, as nervous parents, my wife
and I went to the pre-K school.
And we sat down.
You know they have you sit down
in these little tiny chairs.
And for me, that's a
little bit of a challenge.
So I'm sitting on these little
chairs and the teacher--
we all wanted to know how do
we get our kids ready to go
to preschool.
And so she said the
most important thing
that you can do to get your
child prepared for school
is make sure that they get
a sufficient amount of sleep
before they get here.
And you know I'm looking around
to see did I have something--
does she realized that my
whole life is spent on sleep?
And I went up to
her and she said,
I can tell within
the first 10 minutes
after the children
arrive here if you've
been dragging them around to the
mall and kept them up too late.
And she said I'm just going
to call you on your cell phone
and have you pick them
up because I'm not
going to deal with
them if you have not
let them have sufficient
opportunity for sleep.
So I went up to her
afterwards, and I said have you
been reading articles?
Where did you find
this information?
She said, no, I've been
teaching for more than a decade.
And I know what it's like
to deal with children
who are perfectly well
behaved if they've
gotten a sufficient amount of
sleep but our complete basket
cases if their parents have
kept them up before coming in--
maybe they were on a flight,
maybe they were this, whatever.
To this day, I'm stunned when I
go to the malls or to a Walmart
or to this or that at
10:00 or 11:00 at night
and see in these 24
hour stories people
dragging around their
kids, their young children.
I made the mistake of
commenting to one of the parents
at one point--
don't do that.
But in any case, I
was always struck
by the kindergarten
teacher and what she said.
And the parents of very young
children will often say Johnny
or Susie's--
they're not themselves today.
They're crying, they're
fussy, they're--
because they didn't
sleep last night.
So parents realize that
for very young children.
The teachers realize it for
the 5, 6, and 7-year-old
but then somehow we think
that children grow out of it.
And they don't need to sleep.
But that's just not true.
The behavioral manifestations
are more subtle,
but they are just as serious.
So we have a situation
today in which
one out of five
boys in high school
is diagnosed with attention
deficit hyperactivity disorder.
Now, the symptoms of ADHD--
the symptoms of sleep deficiency
can masquerade perfectly
the symptoms of ADHD.
So difficulty focusing
attention-- we already
see that that's one of
the consequences of sleep
deficiency.
Emotional lability-- that's
another one of the consequences
of sleep deficiency.
Difficulty keeping your
anger under control--
another symptom of
sleep deficiency.
So, yes, there are children with
ADHD who need to be treated.
But there are many, many more
children who don't actually
have ADHD, but they're
misdiagnosed for ADHD
because they're not getting
a sufficient amount of sleep.
And because it can't be that
one out of five high school boys
has this relatively
uncommon condition.
Now, as I mentioned, there
are many, many different
consequences of
sleep deficiency,
and I've just put a few
of them on this slide.
I've talked about the
fact vaccination response,
our distractability, the
increased risk of depression
and suicidal ideation.
Parents who don't set a 10:00
PM bedtime for their kids
in high school, they're children
at significantly greater risk
of depression and
suicidal ideation.
Now, one thing that
sometimes motivates kids.
I was I was driving
home a baby sitter,
and he was about
14 or 15 years old.
He said what do you do?
And I said I do
research on sleep.
And he said what
a waste of time.
I try to get as
little sleep as I can.
And I said OK.
I said it's during sleep that
you release the hormones that
turn you from a boy to a man.
And the next week
his mother called me
and said, what did
you tell my son?
I said, what you mean?
She said well, he's
become a sleep czar.
He's like mom turn
off the radio.
I have to go to sleep.
You're disturbing
my sleep and so on.
And sometimes, we tell-- or I
tell the professional athletes.
I say if you sleep four
hours a night for a week,
you decrease your
levels of testosterone
by an amount that's equivalent
to 11 years of aging.
And they're like
well maybe I should
pay more attention to this.
So let's talk a little
bit about sleep disorders.
And one of the most
common ones is insomnia.
Another very common one is
obstructive sleep apnea.
It affects about one out
of three men and about one
out of six women.
So it's a very common
condition in which
snoring is one of the
most common symptoms
of obstructive sleep apnea.
It increases the risk
of cardiovascular death
by an astounding 420%.
I'm just going to show you a
slide that depicts survival.
So this graph starts
on the left when
the participants in the study
were about age 48 on average.
And it follows there the
percent who are surviving.
And the ones in white are
the ones without sleep apnea
and the ones in red
have sleep apnea.
And we're going to
follow them for 18 years
when they would have
been 66 years old.
And you can see that
at the beginning
there is not a very big
difference between them.
I mean, it's only about a
double the risk of death.
But then you see that the risk
of-- that the percent surviving
is dramatically lower in
those with sleep apnea.
So by the time they would
have been 66, only 58% of them
are still alive
as compared to 94%
of those without sleep apnea.
And sadly, those who
survive in the untreated
sleep apnea group here, they
get a cognitive impairment
about 10 years earlier
and Alzheimer's disease
about five years earlier than
those without sleep apnea.
So it's a real
serious condition.
And if you think that you
might be at risk of it,
you should really go to your
doctor and have it evaluated.
Now, let's see-- there we go.
Well, Benjamin Franklin did say
there will be sleeping enough
in your grave.
And all I can say
is you'll get there
a lot sooner if you
don't get enough sleep.
So what are the things
that steal our sleep?
Well, one of them is a
relatively new invention
is this electronic device the
iPad or some sort of tablet.
And it has two problems.
Not only does it
distract us and keep us
from wanting to go to bed
because we're engaged,
it also bathes us in
blue enriched light
that makes us more alert.
And it also
suppresses the release
of the hormone
melatonin that helps
us to go to sleep at night.
And it shifts our
circadian rhythms
to a later hour making it
more difficult for us to wake
up in the morning, and we're
more tired in the morning.
Other than that, it's no
problem to read from the iPad
before going to sleep.
Caffeine has a six to
nine hour half life.
And it does keep people awake
because it's awake promoting--
people use it stay awake.
But they don't necessarily
realize that it lasts so long.
So I'm always cringe when
I see people ordering
a double espresso after dinner.
And they say, oh, it
doesn't affect me.
And it's true that there are
inter-individual differences
in about one out of four
people have are particularly
sensitive to the side
effects of caffeine as
compared to the others.
But it does disturb
the sleep of everybody.
And, of course, the
television in the room and all
the electronics, they should
be out of the bedroom.
You need to recharge.
They need to recharge.
So maybe it's better to have
them recharge in another room.
It's just something
to think about.
But, of course, the goal is
to be able to get sound sleep.
And to be able to
get sound sleep
and get a sufficient
amount of sleep,
we need to make
sleep a priority.
And so there are
things that you can do.
When you wake up
and that's when you
set your alarm for waking up.
But one thing that
can be very effective
is setting a bedtime
alarm-- figure out
if you need about seven
to eight hours of sleep.
Then if you set an alarm
let's say eight hours--
because you don't sleep every
moment that you're in bed,
so 8 and 1/4 hours
before you know
you need to wake up--
that will help you
remind you that it's
time to go to bed.
But there are several features
that are critical for sleep.
One is duration.
Most adults need
between seven and nine
hours of sleep per night.
It's critical that we get
it at a consistent time.
Disrupting the
timing of your sleep
can have just as adverse
effect as getting
an insufficient amount of sleep.
So consistency in the timing
of when you sleep and wake
is really, really important.
And then finally the
quality of sleep.
If you have a sleep
disorder like sleep apnea
that is making it impossible
for you to breathe and sleep,
for example, at the
same time, then you're
not going to have
good quality sleep.
And that that will
interfere in your ability
to function as well.
If we do get the
sleep that we need,
then we're going
to be more alert,
we're going to perform better,
our athletic performance,
our cognitive performance
will be improved.
And we will also--
just as a side
note, we're actually
more attractive to other people.
There is a study published in
the Journal of the American
Medical Association in which
they took portrait photographs
of individuals when
they had gotten
a sufficient amount of sleep
and then when the hits stayed
up all night.
They showered.
They were all cleaned up for
each of the two portraits.
And people could tell
within four seconds--
they were more attracted to
the same person who was--
these were 700 images.
They've done a very
systematic study.
But they found
that people who had
slept to be more
attractive, they wanted
to spend more time
with them, et cetera,
than the people who
are sleep deprived.
So there are many pluses
to getting the sleep
that you need.
And I thank you for
your attention tonight.
[APPLAUSE]
It gives me great pleasure
to introduce Professor Robert
Stickgold who is
going to be sharing
with you his enormous body of
work about sleep and memory,
so thank you.
[APPLAUSE]
Thank you, Chuck.
And thanks to the
program for inviting me.
I'm delighted to be here.
I'm going to be
talking about sleep.
Yes-- get it or forget it.
I'm going be talking
about why we have to sleep
and what we get from it.
Now, I saw the hands go
up with how many of you
aren't getting enough sleep.
So I think I'll repeat
some of the things
that Chuck said because you
know how that helps, right?
So do we have to sleep?
Well, here's what we know.
We know that rats
die without sleep.
If you sleep deprive
a rat for two weeks,
it will invariably die.
So rats need it.
The same is true for humans.
Now, Harvard
Medical won't let us
do that particular experiment.
But there is a genetic
condition known
as fatal familial insomnia,
which says it all.
It's a prion disease--
Harvard's gotten in my way here.
Can you people see
the bottom of it?
Some can and some can't.
So there's one amino acid here--
oops that's the wrong button--
back, back, back.
There's one amino acid that's
mutated in this protein.
It's a prion disease like
mad cow disease except what
it does is it causes people in
midlife in their 40s and 50s
to slowly lose their
ability to sleep at all.
And within one to four months
after they stop sleeping,
they all die.
So humans need to sleep too.
And maybe the most
impressive data
comes from studies of
sea mammals, cetaceans,
who can't afford to sleep
because if they fell asleep,
they would sink and drown.
And so evolution rather
than simply eliminating
sleep, which would have
been relatively easy
as a genetic fix, instead
taught these animals
to sleep on one half of
their brain at a time.
So they'll be sleeping
with just the right brain,
and then they'll sleep
with just their left brain.
And in that way manage
to keep swimming
even if it's just
a rounding circles
and keep themselves alive.
So they need to
sleep, and you do too.
Now, I'm going to talk
today about several reasons
that you need to sleep.
Main one will be around
memory and learning,
but I'm also going
to review some
of the things Chuck said in
terms of immune function,
in terms of hormone regulation,
and that clearing of toxins
from the brain.
Mood regulation Chuck mentioned
also and learning and memory.
So let's go through
them one at a time.
And let's see if I
can convince you.
If you take a bunch
of individuals
and give them a
vaccination for hepatitis
and then look at the production
of antibodies over time,
it turns out that the
body doesn't really
start manufacturing
the antibodies
until after a couple of weeks.
And for that time, those
subjects you slept normally
and those who were sleep
deprived for one night
after receiving their
immunization shot
look pretty similar.
But over the next two
weeks, you see this effect.
So that by 28 days, people
who were sleep deprived
for one night after
receiving an immunization
will have only half as much
of an antibody production
against the hepatitis making
you much, much more likely
to not have sufficient
immunization to protect you.
Chuck mentioned the effects
on insulin regulation.
This is a study with
subjects, college students,
being restricted to
four hours of sleep
a night-- not total deprivation
but four hours of sleep a night
for five days.
And after that the rate
at which their bodies
could clear glucose out of
their blood was reduced by 40%.
The acute response to
insulin was down by 30%.
And they looked pre-diabetic.
So just five days of half the
record normal amount of sleep
is enough to make you look like
your getting Type 2 diabetes.
And Chuck talked about that
clearance of metabolites
from the brain.
Beta amyloid is one
of the two proteins
that accumulates outside
of the cells in your brain
that is tightly linked to the
development of Alzheimer's
disease.
And when you are asleep, you're
clearing it out of your brain
twice as fast as
when you're awake.
And even a single night
of sleep deprivation
leads to a measurable
increase in the burden
of beta amyloid in the brain.
So I want to talk mostly
about sleep dependent
memory evolution.
I call it memory
evolution because we
used to talk about
memory consolidation.
This idea that
you form a memory.
And a few hours later, it's sort
of cemented into your brain.
And then it's there forever.
But if you have a
spouse of any gender,
you're aware of this
phenomenon that as time
goes, on your memories
of events separate.
Usually, it's your
spouse's memory gets worse.
But that sort of
constant changing
of our memories
over years and years
is what I refer to
as memory evolution.
And it's not just whether
you remember it or not,
but the details of
how you remember it.
So here's an example--
actually this
is something that
chuck referred to also
about the impact of sleep on
just your ability to remember,
in this case, just words.
Here's the protocol.
Subjects either are sleep
deprived for a night--
ah, too many buttons
not enough time--
are either sleep
deprived for a night
or get a normal night of sleep
before coming into the lab
to be exposed to a couple of
hundred words on the screen.
They're neutral negative
and positive words.
They're just asked to indicate
is this a positive word
or negative or neutral word.
And then unbeknownst
to them, when
they come back a
couple of days later,
they receive a surprise test.
It was not unbeknownst
to them here.
It was only unbeknownst
to them there.
So they give them the test, and
it's a simple recognition test.
They show them all
200 words that they
had seen before plus
another 200 and asked them,
which have you've seen
before and which haven't you?
And here is what we see.
In the group that slept
well, the night before they
encoded it, memory
recognition is quite high--
both for the positive words
and the negative words.
It's reduced substantially
for neutral words,
but that's something we
know a lot about our lives
that we remember
the emotional parts.
But when we test them
two days later-- sorry,
when we test the ones
who were sleep deprived--
and, again, they're being
tested after two full nights
of recovery sleep, so
they're not tired anymore.
When we test them
for their memory,
their memory for the positive
words is reduced about in half,
the memory for the negative
words is reduced about in half
but their memory for
the negative words
is mostly maintained.
Meaning that if you
were sleep deprived
when you saw these
words, you are twice as
likely to remember
the negative words
as the positive or neutral ones.
So I'm in the
psychiatry department.
If someone comes into the
psychiatrist and says,
my wife says I have to come
and see a psychiatrist.
She says I'm depressed
because I only remember
the bad things that happen.
Truly he may be depressed,
but he might also just
be sleep deprived.
That's enough to
give you the sense
that only the negative
things are remembered.
That's bad on the
individual level.
It can be catastrophic
on the national level.
I have the suspicion that the
entire cause of the first Gulf
War, seriously, now
was this effect.
Because you had decision
makers who were highly sleep
deprived trying to decide
whether we should attack
or not.
And they're remembering we've
got these satellite photographs
of these trucks that might
be biological warfare weapon
development trucks.
We've got to do
something about it.
And they forget they
were also told that they
look like falafel trucks too.
And that's kind of
funny, but that's
where our mind goes when
we're sleep restricted, when
we're sleep deprived.
And the decisions could
be made on that basis
of an over-remembering,
an overdependence
on negative memories.
Now, that's what
happens when you're
sleep restricted
to sleep deprived
before you learn something.
What my work is
really focused on
and what's really
quite surprising to me
when I found it and
to most other people
is that the sleep you get
after you learn something
is probably more important than
you sleep you get before it.
I am the only lecturer
whose lecture you will ever
attend who will take
it as a compliment
if you fall asleep
while I'm talking.
Because I know
you're just trying
to enhance your
memory of that event.
Now, how big of an
effect does that have?
Here's one example-- I'm going
to take you to three examples
altogether, but this is
just a very simple test.
What you're doing
here is you're trying
to learn to spot these diagonal
bars in the lower left quadrant
of your visual field when
we flash pictures like this
on the screen very quickly.
And what we do when
we train you on
it is we see how fast we
can flash that up there,
and you still have 80% accuracy
in detecting whether those bars
or above each other like
they are there or next
to each other.
And then we bring you
back 12 hours later
and give you the exact same
test and again see how fast we
can go before you can't do it.
What do we find?
Well, I'm sorry, I'm
saying we bring you back.
I'm assuming you're all
undergraduates, yes,
because that's how we
did this study with.
What we find is that if
we retest these subjects
after 3, 6, or 9
or 12 hours there's
no improvement in how fast
they can do the task if they're
awake during this time.
But if we let them sleep
between training and testing,
they're about 15% to 20% faster.
Doesn't matter how long
the time interval is,
it only matters whether
they slept or not.
And, in fact, we can wait
even longer to test them.
These are groups of
subjects who were tested--
I showed you the 0 and
1 day data, but these
are other groups
tested after 3, 4--
2, 3, 4, or 7 days, and
they continue to get better
without any practice.
So it's not practice
that makes perfect.
It's practice plus sleep
that makes perfect.
And the terrifying finding
is that if you sleep deprived
subjects for the first
night after you train them
subsequent sleep is of
no value whatsoever.
So that after two full
nights of recovery sleep,
their performance here
is not significantly
different from baseline.
So you have to get sleep and
you have to get it tonight.
There is this concept
of sleep bulimia,
which is a binge purge concept
college students love it.
They binge sleep on
the weekends and then
they purge getting four or five
hours a night during the week.
And they tell us
that they're fine.
They make it up on the weekend.
Well, they might it up
in terms of getting back
to full alertness, but
it's really too late
to remember what they
didn't remember because they
didn't sleep that first night.
Now.
Sleep does much more
complicated things
than simply make us faster
or stronger in our memories.
It can do things like
enhanced verbal memory
in some unexpected ways.
So we did a study and Jessica
Payne was the lead on this.
I'm sorry, a lot of my
slides will have my coworkers
and students listed.
I should be clear that whenever
I say we did something,
I mean they did something.
So with that admission,
let me go forward.
What the subjects in this study
that is they heard on a tape
eight lists of words, and we're
told try to remember the words.
We're going to test
you on them later.
And then either 20 minutes
later or 12 hours later,
we would test them.
I'm going to give you a
sense of what that's like.
I'm going to show you one list.
Now, they heard it
on an audio tape.
I'm going to show
you the list, and I'm
going to give you the same
instructions as I gave them.
Try to remember
these words, you're
going to be tested on it.
OK, so in the actual study,
there were eight lists not one.
It was auditory not visual.
And we actually just gave them
a blank sheet of paper at retest
and had them write down
what they remembered.
That would be cumbersome here.
So I'm going to show you words
and ask you to raise your hands
if you remember seeing them.
Now, for those of
you who aren't MDs,
you might not know that
there are extensor muscles
in this part of the arm.
This is not raising your hand.
This is not raising your hand.
I want everybody around you
to see how smart you are, OK?
So for each of these words,
if you remember seeing it,
raise your hand.
Oh, good.
It's always embarrassing
when we get--
[LAUGHTER]
OK, good, excellent, good--
What can I say?
Well, if you looked around,
you know you weren't alone.
In fact, all eight lists
were generated the same way.
We gave words like
sleep to a couple
of hundred psych students in
introductory psych in college
and said write down the first
10 words that come to your mind
when you think of sleep.
And then we took the 10
or 12 that they wrote down
most commonly.
And for each of the lists,
we would show the subjects
in our study those words but not
the word that it was based on.
And what we see is that
classically 60% to 80%,
it looked like more like
90% of the subjects here,
will mistakenly respond that
they remember seeing the word.
And that's because our brain
is always extracting gist.
When you go home
and tell your family
and you call your friends
to talk about my great talk,
you'll say he showed us all
the words related to sleep.
And it doesn't matter what
the words were, right?
It's just the gist
that's important.
And our brain is very
good at identifying those
just and holding onto them.
So the question that Jess
Payne asked was the following--
what happens to that
memory over time?
So we had four
groups of subjects--
some were trained
in the morning.
Two groups in the morning and
two trained in the evening.
In each condition, one group
was tested after just 20 minutes
to give us a sense of how well
they formed these memories.
And the other group was
tested after 12 hours.
And we can look
at the difference
to see how much are they
forgetting across 12 hours.
Now, the ones who were
trained in the morning
and tested that evening
were awake for the 12 hours.
We told them no naps.
Whereas, those
trained in the evening
tested and next morning got a
full night's sleep in between.
And what do we see?
Well, first of all, for
those in the wake group,
across the day, they forget
about 40%, 45% of the words
that the 20 minute
group could remember.
And even have to sleep,
they're forgetting about 25%
of those words.
That's the words that
they actually saw.
But when you look at the
words that weren't shown,
those are just words that
the brain came up with,
they're still forgetting about
20% of them across a day awake.
But across the night, the brain
holds on to them tenaciously.
It's holding onto
the memory of what
it thinks is most important.
So that when you wake
up in the morning
you have a memory that might be
less accurate but more useful
in understanding
what had happened.
Now, you could
imagine this happening
for evolutionary reasons.
In the previo-- no,
wrong talk, sorry.
Sleep deprived?
So there are even--
yeah, I need more
sleep, it's true.
There are even more
sophisticated and impressive
things that the brain
does with our memories
while we're asleep.
And here's an example.
In this study subjects were
shown 1, 2, or 3 of these cards
on each of 200 trials.
And asked to predict
whether it was
going to be sunny or rainy
in this simulated world which
might not seem obvious to you.
But, fortunately, on these 200
trials, we gave them feedback.
So, for example,
on the first trial,
they might see this card.
And it turns out to be sunny.
And if they're undergraduates
they say, "whatever."
And then in the
second trial they
might see these
two cards together,
and it turns out to be rainy.
And one of the fun things
about the human brain
is that it's always making
models and coming up
with hypotheses and
trying to understand.
So most of you at this
point have probably
sort of said to yourself--
OK, that one means sunny.
And these two mean rainy.
And I don't remember
what the fourth one was
but that one probably
means sunny too.
So we build these models.
And then across 200
trials, we test them.
And so indeed along comes,
the third trial and they
say, OK, I've got this one.
And it turns out to be rainy.
And now they're
totally confused.
In fact, they think I must
not have remembered correctly
what happened here.
But the gimmick in this study
is that each of the cards
has a certain
probability of being
associated with sun or rain.
So 80% of the times
you see the triangles,
it's going to turn
out to be rainy.
But only 20% of the time you
see the squares would be rainy.
And although no one can
quite grasp this all,
they get a good model of it.
It's a kind of learning that
we call probabilistic learning
and humans are horrible at it.
But they get the gist.
So that after these 200 trials
always with the feedback
of the correct answer.
We give them 100 trials
with no feedback,
and ask whether they're
guessing the optimal choice.
And they get 70, 80 of
them out of 100 correct.
They're doing really well.
Nobody's getting 100.
Nobody really understands
the rules fully,
but they're pretty good at it.
Then we send them
away for 12 hours
and do the exact same
test, same 100 words--
sorry, same 100 stimuli.
And in the subjects who
were trained in the morning
and tested that
evening without sleep,
they get a couple of extra
cards correct but not
significantly more than
they were at baseline.
It's impressive that they
remember what they learned,
but they certainly
aren't getting better.
After a night's sleep,
they're 10% better.
They're doing better on this
task after a night of sleep
than they were right
after they learned it.
In a very real
sense, these subjects
when they wake up in the morning
have a better understanding
of how the world works
than they had when they
went to bed the night before.
And that's what
sleep is giving them.
So you do need to sleep or
rather you need to sleep.
You need to sleep to maintain
alertness and optimal cognitive
functioning, to optimize
your immune defenses,
to maintain hormonal
regulation and weight,
to prevent beta amyloid buildup
and Alzheimer's, to permit
sleep dependent learning
and memory consolidation,
and, as Chuck pointed
out, just to be happy.
Or to put it another way, if
you don't get enough sleep,
you'll end up stupid,
fat, sick, and unhappy.
The choice is yours, thank you
[APPLAUSE]
I'll introduce you.
It's now my pleasure to
introduce Judy Owens,
she's the director of sleep
medicine at Boston's Children's
Hospital and a professor of
neurology at Harvard Medical
School.
I was going to point to that
one more time and just say
the need for sleep in children
just can't be overemphasized.
I've always said that
the phone call from hell
is when a parent gets
the call that says,
hi, I'm bringing Timmy
over for his play dates.
Oh, and he didn't nap today.
Judy.
Well, that's a great segue.
So my task in this
last 20 minutes or so
is to take some of the wonderful
information you've already
learned from Dr.
Stickgold and Dr. Czeisler
and put it into the lens
of the teenage brain.
And we know that there is a
lot of drama in adolescence
and there's just
as much drama when
we talk about adolescent sleep.
So the first thing
I'd like to do
is cover some common
myths and misconceptions
that I hear all the time
from folks like yourselves
that come to hear folks
like myself talk about
sleep in teens.
Number one-- teens
would go to sleep
earlier if their parents
just made them do it.
So it's all a matter of
bad parenting, lax parents
who are just letting their
kids get away with stuff.
Some teens might need
nine hours of sleep
but mine does just
fine with six.
And, as a matter
of fact, so do I.
Take the cell phones, the
laptops, the television, et
cetera away and kids
will fall asleep.
If school starts later,
they'll just stay up later,
and they won't get
any more sleep.
Teens can make up for lost sleep
by sleeping in on the weekends.
So that's the solution.
And kids need to learn to get
up earlier, that's real life.
They're going to have
to do that as adults.
And what's the harm anyway?
OK, let's look at some basics.
So this is what we
call the two process
model of sleep regulation.
And it's important to
understand, particularly
when you're thinking
about adolescent sleep,
because it kind
of explains why we
feel relatively more awake
or more tired at any given
time of the day.
So the first thing
that regulates sleep
is what we call the sleep drive.
And Dr. Czeisler mentioned that
the accumulation of adenosine
in the brain, as well
as other neuro chemicals
called somnogens, which
essentially make you sleepy.
And that builds in a
fairly linear fashion
throughout the course
of the day and then
is dissipated over a
normal night's sleep.
The other process
that regulates sleep
is what we call the circadian
rhythm or the circadian
drive towards wakefulness.
The biomarker of
which is melatonin--
the hormone of darkness.
And so circadian
rhythms are essentially
a 24-hour predictable
peaks and troughs
of relative alertness and
sleepiness throughout the 24
hour day.
So that, for example, around 3
to 5 o'clock in the afternoon,
we all feel a little bit sleepy.
And we might reach for a
Diet Coke or for a Starbucks.
That's a natural trough
of circadian alertness.
But we also have
something called
the forbidden zone or the
second wind phenomenon,
which is the surge of
circadian based alertness
that we all feel in that hour
or so just before our bodies are
ready to fall
asleep which kind of
allows us to stay awake in the
face of a mounting sleep drive.
And then, finally, there's
the circadian nadir round
3:00 to 5:00 in
the morning, which
is the lowest point of
alertness in the 24 hour day.
Now, I want you to
keep this graph in mind
and imagine it shifting
two hours later when
we talk about what's going
on with sleep in adolescence.
This was mentioned by the
previous two speakers a bit,
but the importance
of recognizing
that it's not just how much you
sleep but when you sleep that
is important.
Because we now recognize
that in addition
to this master clock in the
brain that determines when
we sleep and wake, there
are also circadian clocks
in all the cells in the body
and all the different systems,
physiologic systems in the body.
So that misalignment between
these internal circadian clocks
and the external
environment can result
in some of the profound health
impairments that have already
been discussed.
So that leads to
this concept of what
we call deficient sleep,
which acknowledges
that both short
sleep in relationship
to the amount of sleep that
you need and misalignment
of the circadian system
are equally important
and both contribute to the
behavioral and cognitive
impairments and poor
health outcomes.
So when we talk about what
happens to sleep in adolescence
there is really this aspect
of the perfect storm.
So what we have first of
all is all adolescents
experience a normal shift or
delay in their fall asleep time
and their wake
time in association
with the onset of puberty.
So they develop more of what we
call an eveningness chronotype
or a night owl tendency.
So this results in
a shift of two hours
or sometimes more of
the time that they're
able to fall asleep and wake up.
And also the sleep drive
slows during adolescence
so they are able to
stay awake later.
And on a practical level,
due to that forbidden zone--
that surge in alertness
before a bodies
are ready to fall asleep--
it's very difficult for
the average teenager
to fall asleep much before 11
o'clock on a regular basis.
Teens can not make themselves
fall asleep earlier.
Now, of course, there are
environmental influences
on all of this.
All the competing
priorities for sleep
like extracurricular
activities, homework,
after school employment.
And this issue of electronic .
Devices the blue light of which
as Czeisler mentioned actually
suppresses your body's release
of melatonin in the evening
and makes it more
difficult to fall asleep.
And we know that many teenagers
consume caffeinated beverages,
particularly energy drinks.
And that also may be
exacerbating their difficulty
in falling asleep at night.
And I'll talk a little bit
at the end about the role
of early start times.
I just want to talk
a little bit more
about this electronic
devices issue.
Because in a study
that we recently
conducted in
adolescence, we looked
at whether self-reported use of
these electronic light emitting
devices, like
smartphones or laptops,
just before bed, how that
impacted sleep duration
in these students?
So what we found
as you might expect
is the students who
were more likely to use
these light emitting devices
got less sleep than the students
who did not use them.
However, and the
reason for this study
was to look at the impact of
delaying school start times,
is that the students who
use these devices before bed
and those who didn't both got
more sleep after the school
start times change.
Implying that even using
these light emitting devices
doesn't alter the
potential benefits
of changing school start times.
So it's very
important to eliminate
this use of electronic
devices at bedtime,
but school start
time change can have
an even more powerful effect.
There's also a phenomenon,
which we call social jet lag.
So what a teenagers
do on the weekends?
They sleep until noon or 1
o'clock in the afternoon.
But this doesn't really, as a
Dr. Stickgold clearly showed,
this doesn't really
reverse the impairments
that they experience
during the week.
And it further
exacerbates this tendency
to sleep, fall asleep later,
and sleep later in the morning.
So if you fall asleep-- if
you sleep until 1 o'clock
on Sunday afternoon,
there's no way
you're going to build up
enough of a sleep drive
in order to be able to fall
asleep at a decent hour come
Sunday night.
And that results in this
situation of social jet lag.
So you may know that lag
for each time zone crossed,
it takes one day to recover.
So these kids are essentially
in a permanent jet lag
because they shift
on the weekends.
And then they try to shift
back during the week.
And they shift again
in the weekends.
And think about what you feel
like when you have jet lag.
It's not just you're sleepy,
but you're irritable.
You may have all kinds
of physical complaints.
It's not fun.
And that's the way these
kids feel most of the time.
So these changes, these
biologically based changes
are in direct conflict with
earlier school start times.
Because essentially you're
asking these kids to wake
up at that circadian nadir,
that lowest point of alertness
in the 24 hour day.
It's like asking all of
us to wake up at 3 o'clock
in the morning and
go to calculus class.
How would that feel?
And not only that, but REM,
a rapid-eye movement sleep,
is concentrated in the
last third of the night.
So if you have to
wake up too early,
what you're going
to get robbed of
is your full complement
of REM sleep.
And as you've heard that has
a critical potential effect
on learning, especially
learning of new tasks.
And, furthermore, for
optimal health, safety,
and achievement-- and that's
what we all want for our kids--
the average middle and
high school student
needs 8 to 10 hours
of sleep a night.
We'll see how close
we get to that.
So you've heard a
lot of this already.
I'm just going to go
really briefly over this.
But as it relates to
the teenage brain,
sleep restriction
and deficient sleep
have selective effects on
this area of the brain called
the prefrontal cortex,
which is intimately involved
in the genesis of
symptoms of ADHD
but affect really important
higher level functions,
like decision making and
problem solving and monitoring
and modifying your behavior.
And furthermore, these
executive functions
are undergoing their most rapid
development during adolescence.
So at this period when the
brain is most vulnerable,
you're subjecting these
kids to a situation that
is going to negatively
affect these particular brain
processes.
You've also heard about
the affect of sleep
on emotional regulation.
So essentially what
you have is sort
of the classic
teenage scenario--
a heightened emotional
response to everything
but with less sort of control
over that emotional response.
So maybe it's not
all due to hormones.
Maybe a lot of emotional
reactivity in teens
is related to not
getting enough sleep.
And, finally, sleep
also affects areas
of the brain that are important
for reward related function.
And this area of the
brain the striatum
is also undergoing some
important developmental changes
during the teenage years.
And studies suggest
that insufficient sleep
is linked to changes in
reward-related decision
making so that people take
greater risks because they
assume less in the way
of negative consequences
for their behavior.
So how does this all
play out in teens?
Just a grim reminder that
the first and third cause
of death in adolescence
in this country
are number one accidents
including car accidents
and number three is suicide.
So how does that relate
to teens and sleep?
Well, for example, in one
study, very large study
of high school
students, almost 40%
overall got insufficient sleep.
And it got worse as
they went up in grades.
So the percent of students
who are getting less than
or equal to six hours when
they were in eighth grade
was about 20% but increased
to over half to 56%
by the time they
were in 12th grade.
And minority students
were more likely to get
insufficient sleep.
40% of the teens
in the study who
got six or less hours of sleep
reported depression symptoms.
And almost three
times as many students
getting less than
six hours of sleep
reported alcohol use
in the past 30 days
compared to those getting
more than nine hours.
So this risk taking, this
emotional regulation,
this poor decision
making plays out
in some very important
health and safety outcomes.
Motor vehicle crashes--
two-thirds of accidental injury
fatalities in adolescence
are related to road crashes.
And study after study has
shown that adolescent drivers
are more likely to
report drowsy driving.
And that is clearly
a risk factor
for becoming involved
in car accidents.
You've heard about the
relationship between sleep
and certain neurohormones
that control appetite.
But there are lots
of other reasons
why people who are sleep
deprived may gain weight.
They tend to eat more food,
higher calorie and higher
fat content food.
If you're getting up late,
you may skip breakfast
and have most of your calorie
intake in the evening, which
is a contributor to the
development of obesity.
If you're too tired
to exercise, that's
going to add to the problem.
And you have these
effects of sleep loss
on cardiovascular function
added to the effects
of obesity on cardiovascular
function and insulin
resistance and metabolism.
And in addition to that,
people who are obese
are more likely to
have sleep apnea.
And that adds another
dimension to the risk
for cardiovascular and
metabolic health problems.
So I wanted to leave you
with a little bit of optimism
about all this and offer
one potential solution
to the epidemic of insufficient
sleep and deficient
sleep in adolescence.
And that is healthy
school start times.
I was privileged to be the lead
author of the 2014 American
Academy of Pediatrics
policy statement advocating
for start times of 8:30 or later
as being in the best interests
of our nation's youth.
And this concept has been
endorsed by many organizations,
including the American Medical
Association, the American
Psychological Association, the
American Thoracic Association,
the NEA, and the national PTA.
So there are lots of people
who are on board with us.
Because some of
the outcomes that
have been shown in
the studies that
have looked at the
impact of delaying school
start time for middle
and high school students
found that bedtimes remain
approximately the same
or may even shift earlier.
But because they're sleeping
in later in the morning,
these students obtain
significantly more sleep,
particularly that
critical morning sleep,
the REM sleep that I mentioned.
The later the start time,
the greater the sleep amounts
but even relatively small
amounts can result .
In significant improvements.
And students report
being less sleepy.
And it really does seem
like that 8:30 or later
is the sweet spot both in
terms of allowing students
to get the sleep they
need but also to get it
at the right time
that is in concert
with their circadian rhythms.
In terms of school performance,
tardiness rates go down,
absenteeism goes
down, dropout rates
decline, graduation rates
increase in schools that
have delayed their start times.
and grades overall improve,
particularly in the morning
classes as you might imagine,
but in core subjects,
like English, math, science.
And there's some
evidence to suggest
that disadvantaged
students, students
who are at the lower end of
academic success and minority
students, may benefit even more
from school start times change.
Standardized test scores improve
and delayed school start times
are also associated with
improvements in mood.
Every single study shows
that self-reported symptoms
of depression go down.
Less visits to the health center
and, perhaps, most importantly,
now there is evidence to suggest
that changing school start
times can decrease the risk
of students being involved
in car crashes by as much as
65% to 70% in some studies.
Now, as a public health
person, it's hard for me
to imagine another strategy that
could affect mortality, could
affect death rates
from car accidents,
as much as this could.
And, of course, we
can't absolutely
draw a cause and effect
from these studies,
but the evidence is
accumulating that there
is this association between
later school start times
and fewer accidents in general,
but particularly car accidents.
And, finally, if you just want
to talk dollars and cents,
there was a great
study published
by the RAND Corporation
that looked at-- they used
an economic modeling of
what would happen state
by state if the whole state
changed their school start
times to 8:30 or later.
They did that in 47 states.
And the way that they
calculated this was to look at,
well, it's going to cost about
$150 per student per year,
and that's largely related
to transportation costs
as buying more buses,
et cetera, plus $110,000
for infrastructure,
maybe lighting
playing fields so athletic
teams can play later
in the afternoon.
But then they balanced that
looking at projected lifetime
earnings based on improved
graduation rates and improved
standardized test
scores plus what
you would gain by having
fewer students involved
in car crashes.
And looking this out--
modeling this out for 15 years,
as examined by the study,
the average annual gain
based on those parameters
to the US economy would be
about $9.3 billion per year.
In some states like
Massachusetts being one of them
would break even in terms of
the cost of changing start
times in just two years and then
start to actually make money.
So this study really suggests
that delaying school start
times is a cost effective
population level
strategy, which could
have a significant effect
on the health of
our nation's youth
as well as the US economy.
Thank you, very much.
[APPLAUSE]
Wonderful to see all the people
who are coming home to bed.
That was was terrific, Judy.
Oh, thank you.
There's so much new data.
I know, it's really exciting.
Fantastic, yes.
It's just the evidence
is so irrefutable.
All right.
Well, thank you all for coming.
For those of you
who have to leave
and for those of
you who are staying,
we're happy to take questions.
So we have a few questions.
Actually, many more than
we could possibly answer.
I've tried to kind of
group them together. .
And why don't we start with
Bob's got some questions
about napping.
There are a whole bunch of
questions about napping.
I'll just give you
a sense of them.
Efficacy of naps to
meet the body's need.
Is it better to stay--
oh, that's not one.
Oh, these are the new
ones you gave me, Chuck.
How often should we nap?
Can we catch up on missed sleep?
Is it possible to
make up lost sleep
by napping during the day?
So some napping is
wonderful, isn't it?
I sort of personally believe I
should nap every chance I get.
They are effective
in terms of meeting
our sleep need of eight or nine,
seven to nine hours of sleep
a night.
Naps are hour-for-hour just as
effective as sleep at night.
But when it comes to
memory processing,
it turns out that a 90
minute nap gives as much
benefit as an eight hour night.
This is something that
has stunned us, actually.
And we've seen it time and
time again, that, in fact,
a 90 minute nap in the afternoon
produces more memory benefit
than a six hour night.
So there's something
special about naps.
Someone asked how
often should we nap?
There is no how
often you should nap.
You should not
probably count on naps
to make up for lost
nights, although you
can use them that way.
Preventative napping is
something I wouldn't recommend.
I wouldn't recommend trying
to nap so that you can not
sleep as much as night.
But when you need to
nap and when you do nap,
it seems to be very effective.
Now having said
that, we don't have
data for issues like
immune function endocrine
function, hormonal
function, clearance
of toxins from the brain.
We don't have nap
studies for those.
And so the issue
of how well they
work compared to a night of
sleep, that information we
don't know.
One thing I would just clarify.
Naps are not a substitute
for sleeping at night.
So I once had a
police officer come up
and I was talking about
the benefits of napping.
And he said, well,
doctor, I just
want to let you know that
that's exactly what I do.
I nap in the afternoon.
But then he explained
to me his schedule.
He didn't sleep at all at night.
So he was sleeping
two hours a day.
So that's certainly
not a good plan.
That's a very bad plan.
And again, the time that
you nap is important also.
Because if you nap later in
the afternoon into the evening,
then you're reducing
that sleep pressure
and it becomes much harder
to fall asleep at night.
So optimal time for naps is
probably early afternoon.
I mean, at the
classic siesta time.
And Professor Owens has
some questions about sleep.
Yeah.
So I have several questions
about how much sleep
kids at different ages need.
And I think there's--
the American Academy
of Sleep Medicine
has optimal sleep amounts
posted on their website
for kids of different ages,
as does the National Sleep
Foundation.
But what I would
say about that--
and it happened today
that I had a patient,
a family come in with
a 3-year-old boy.
And the parents were
concerned that the child
wasn't getting enough
sleep because they
didn't fit the numbers.
And first of all,
there's always a range.
So this particular question
was about a 10-year.
How much sleep does a
10-year-old boy need?
Somewhere probably
between 10 and 12 hours.
But it's always a range.
And there were three questions
that I asked this family.
Does your child wake up
by themselves at the time
when they need to wake
up in the morning?
If the answer is yes, then
that means they've probably
gotten enough sleep.
When given the opportunity,
do they sleep longer?
So on the weekends, do
they get 10 hours of sleep
during the week, but then
they get, when able to,
they take 12 hours of sleep?
That probably means that their
weekday sleep is not enough.
And finally, how is
your child functioning?
Are they happy?
Do they wake up in a good mood?
Are they paying
attention in school?
Are there any concerns
on the teacher's part?
And if the answer
to that is no, then
don't worry so much
about the numbers.
If that makes sense.
One of the questions we got
is are there negative health
effects to sleeping too much?
Because we talked a lot
about the adverse health
effects of sleeping too little.
Now epidemiologic
data does indicate
that people who sleep
more than 10 hours a night
have increased risk of death.
So you could conclude from that
that sleeping too much is bad.
But that is not
generally-- first of all,
the number of people
in those groups
when they do the
epidemiologic studies who
are slipping 11 or
12 hours a night
are very small compared
to the overall population,
because that's very
uncommon in our society.
Secondly, sleeping a lot could
be a symptom of a disease.
I mean, when I was in
college, I had toxoplasmosis.
Anyway, I was sleeping
like 20 hours a day.
Not because-- because I was ill.
And many times, you don't even
know the cause of the illness
at that point.
So the general
interpretation of the data
indicating that
people who sleep a lot
are at higher risk
of diseases, they
may not realize that
they have a disease.
But they may have some early
manifestation of an illness
that later comes to light.
And why is that the view?
Well, if you take healthy
people and bring them
into the laboratory and have
them spend 14 hours a night
in bed in the dark, instructed
to sleep for a month--
you might think this
is the ideal job.
All you have to do
is go into the lab
and sleep every
night for 14 hours.
And it turns out, the first--
if you just take people who are
sleeping seven to eight hours,
the first night they might
sleep 11 or 12 hours.
And then next night, 10
or 11 hours, and so on.
But it's not like eating.
We can't really oversleep.
So after the first
week, the second week,
by the end of the
fourth week, they're
sleeping on average about
8.2 to 8.4 hours per night,
even though they're in
bed 14 hours a night.
So we can't really--
it's not like overeating
where we can gain weight.
We can't oversleep continuously
and somehow build up
some sort of adverse effect.
So in fact, the sleep
system, once it is satiated
and once we have paid back
the sleep debt that we often
carry around--
and Bill Dement, who was
my advisor in college
and who was critical in the
understanding and development
of concepts behind
REM sleep, he often
would say that the sleep
debt, the national sleep debt,
is greater than
the national debt
because we are so chronically
sleep-deprived as a society.
And the average
person in that study
didn't get to the
8.2 hours per night
until they paid back about
30 hours of sleep debt
that they were carrying
around by sleeping
a couple of extra hours.
Now many people sometimes
feel more groggy
if occasionally they sleep in.
And that's probably
a reflection--
because we all experienced a
phenomenon called sleep inertia
where the deeper we
sleep, the more groggy
we are when we wake up.
And probably if you pay back
a lot of the sleep debt in one
go, you may feeling a little
groggy when you wake up.
But that's only because
you're beginning on the road
to recovery.
Not because sleeping
too long is detrimental.
So Bob, you have
another question?
Are geniuses-- writers,
artists, scientists--
disproportionately
sleep deprived?
Question.
If we solved the
sleep crisis, would
the pace of human
advancement appreciably slow?
There is this
concept that people
who burn the candle
at both ends are more
productive than other people.
In fact, Bill
Gates once famously
said that when his teams have
a deadline to get a product out
there, they can program 72
hours straight without sleep.
And my response is yes,
but the product is Windows.
[LAUGHTER]
So I don't-- there's this belief
that the number of hours you
work is a measure of
your productivity.
And it's not.
I mean, great advances by
writers, artists, scientists,
those breakthrough discoveries,
those brilliant insights,
don't come from long hours.
They probably come from
well-rested brains.
In fact, I'm convinced that
the reason that Newton came up
with his theory of gravity was
not because the apple hit him
on his head but because he had
been napping under that tree.
There you go.
[LAUGHTER]
And there's actually
lots of evidence
of major creative discoveries,
the scientists reporting
it themselves
occurring during sleep.
Because it is that insight that
is gained during particularly
REM sleep that helps us to,
as Bob so eloquently describe,
bring together the information
of the individual things
that we have learned,
integrated with everything
that we have previously known.
And it's duly noted,
most of your REM sleep
comes at the end of the
night and not the start.
And one of the
related questions is,
many successful CEOs say that
they get very little sleep.
And that is--
Thomas Edison, he had a little
bit of a vested interest
in this because he didn't
want his employees to sleep.
And so he was always extolling
the virtues of staying awake.
But in fact, many CEOs, present
day CEOs like Jeff Bezos,
they talk extensively
on how important
it is for them to get
the sleep that they need.
And that they spend at least
eight or nine hours in bed
every night.
And Tim Cook at Apple is
also famous for talking
about the importance of
getting enough sleep.
So I think that many times--
you know, when we hear people
who claim that they don't sleep
at all or whatever,
when they actually
come into the laboratory,
that usually doesn't bear out.
In fact, we had
one individual who
claimed that he needed so little
sleep that he had a second job,
and that he was--
and he felt sorry for people
who needed to sleep eight hours
a night.
So we brought him
to the laboratory.
He didn't know what time it is.
No clocks, no radios,
no information source
of the time of day.
And immediately, he
expanded his sleep.
And he said, you know, I've
never felt better in my life.
This is great.
What's happening here?
And so on.
And I told him, well, you're
sleeping almost eight hours
a night.
And he said, well,
maybe I was exhausted.
[LAUGHTER]
So I have a couple questions
about special populations
of children.
First, kids with ADHD
and kids with autism.
Special populations.
Special populations, yes.
Sorry.
So I would say a couple
things about that.
Many, many of kids
both with ADHD,
particularly with autism
spectrum disorders,
have significant sleep problems.
I think there's no
question about that.
With kids with
ADHD in particular,
they tend to have
problems falling asleep.
Kids with autism oftentimes
wake up during the night.
They may have relatively
short sleep duration.
And I think the jury
is still out a bit
as to whether they actually
need less sleep than typically
developing children.
But I think-- a couple
of points about that.
One is that if children
within those populations
have sleep problems, that
many of the same behavioral
interventions that we use in
typically developing children
also work really well in
those populations as well.
There is some evidence, there
are a number of studies now
which have suggested
that children
with ADHD and with autism
both may have changes
in the release of melatonin
in the evening that may impact
on their ability to
fall asleep at a sort
of regular, appropriate time.
And there is also
some data to suggest
that the use of
artificial melatonin
may help these children.
But I would add a very large
note of caution to that
in saying that any time you
use any kind of sedating
medication-- and this goes for
adults as well as children--
you have to couple that with
the behavioral interventions.
Because otherwise, when you
stop whatever medication it is,
whether that's over-the-counter
or prescription,
the problem is still
going to be there
unless you've instituted the
behavioral strategies that
really result in long
term improvements.
I ran an ADHD
clinic for 25 years.
And I don't-- all-in-all, and
the studies kind of bear this
out, is that ADHD
medications during the day,
because they wear off
relatively quickly--
most of these medications
are out of your system
by dinnertime--
for the most part, don't
directly affect sleep onset
in kids with ADHD.
But I think what
happens more frequently
is they're unmedicated.
In that time between
dinnertime and bedtime,
they're ADHD symptoms come back.
The impulse control, the
hyperactivity, et cetera.
And that contributes
to their problems
settling rather than it being
a direct effect of medication
per se.
But in terms of addressing
sleep problems, particularly
in kids with autism, I
very often refer parents
to the Autism Treatment
Network website,
which has wonderful resources,
particularly about sleep,
and has one of the most
well-balanced summaries
of the pros and cons
of using melatonin
in children that I have seen.
So that's a great resource
for parents who are struggling
with these kinds of issues.
You want the name
of the website?
It's Autism Treatment Network.
Two more questions.
Two more questions.
And we have so many.
I know.
I'm going to break your rule
right away by answering two
YouTube questions very shortly.
To what extent does
daytime activity levels
affect the required
sleep time at night?
In terms of physical
activity, I think
the answer is just about zero.
Your heavy labor
doesn't particularly
need more sleep time.
Is this right?
Chuck, you agree?
I agree.
Than your college
professor whose greatest
physical activity
is clicking a mouse.
At the same time, emotional
work, emotional distress,
might lead to a need
for greater sleep
and might produce greater sleep.
And a lot of exercise
might increase the depth--
That's the second one.
How does the timing of
exercise affect sleep?
Do you recommend workouts
in the morning or evening?
So anything that raises
your core body temperature,
your body temperature
deep inside,
will facilitate your sleep.
So exercise or hot
tubs can make it easier
to fall asleep and
deepen your sleep.
But you don't want to get it
too close to the onset of sleep.
So up to an hour before
bedtime is probably optimal.
Both from YouTube.
And for the second
group of questions.
[LAUGHTER]
You can't shut us up.
[LAUGHTER]
I'm going to group together two.
It's a bit of a stretch
to call these a group.
But one is about
the work schedules
of resident physicians,
which are appalling.
And we've just taken a
step backwards in which,
notwithstanding all
the evidence that
was produced showing that
resident physicians who
work these extended duration
shifts are at increased
risk of car crashes,
increased risk
of making serious medical errors
in the care of the patients
that they're treating, increased
risk of stabbing themselves
with needles.
Nonetheless, the
restrictions which
were in place for a few
years have been lifted.
And so now they're
again able to schedule
them to work these very
extended duration shifts much--
which I think is
a major mistake.
And then they wonder why so
many physicians are burned out.
And so on.
And the correlated
question is why do they
keep waking patients
in the hospital
if sleep is so
important for health?
And I don't know the
answer to that question.
It can be a little
bizarre in the hospital.
And the final series
here is all about
inter-individual
differences in sleep need.
Yes, there are
inter-individual differences
in the need for sleep.
And yes, the amount of sleep
that we get as we get older--
a lot of questions
about sleep and aging--
the amount of sleep that
we can get decreases.
And the depth of
sleep also decreases.
It doesn't really
answer the question
of whether we need less sleep.
It's just maybe that we are
not able to get as much sleep
as we get older.
And the number of awakenings
during the night increases.
But I just want to say
one thing about awake--
and there are inter-individual
differences in the time
that people spend in bed.
But the number of people
who need five hours or less
of sleep per night,
expressed as a percent
and rounded to a
whole number, is 0%.
So if you're getting
that little sleep,
you're undoubtedly getting an
insufficient amount of sleep.
And that's a quote from one
of my colleagues, Tom Roth,
who expressed it beautifully.
But a lot of people think
that their sleep is perfect
if they never wake
up during the night.
And in fact, it's normal for
us to wake up during the night.
We may get up, go to the
bathroom, this, that.
And if we're getting,
the ones who--
going back to the
resident physicians--
the ones who never
wake up are those who
are severely sleep-deprived.
So when we study resident
physicians sleep and they're
only getting four or five
hours of sleep at night,
they sleep solidly.
The moment they go to sleep,
they go to bed, they're asleep.
The moment they
wake up, they're up.
So people who say I'm
a champion sleeper.
I can fall asleep
anywhere, anytime.
On a bus, on a plane, anywhere.
They actually probably are
chronically sleep-deprived.
And because it is normal--
so in individuals back a
couple hundred years ago
before the advent of
artificial light, probably
people had segmented sleep.
There's evidence from historians
that they slept deep sleep
in the beginning of the night.
Woke up, tended the animals.
Some people think that most
children were conceived then
in the middle of the
night awakenings.
And then people would go back
for the sweet sleep, the REM
sleep of the morning hours.
And then finally
get up out of bed.
So we have medicalized
the concept
that if you wake up a time or
two during the night that you
need a drug.
But actually, it may be
quite normal to awaken
during the night.
And that may be a sign
that you're actually
getting enough sleep.
[APPLAUSE]
