Another hypothesis regarding the biological factors that play a role in
schizophrenia is the dopamine hypothesis. This hypothesis suggests that
schizophrenia involves excess dopamine activity. One reason this hypothesis
came about was from the observation of individuals who overdose on major
stimulants like methamphetamine and cocaine. These individuals, if you recall
from our lesson on drugs, have similar behaviors and cognitions as those
individuals with schizophrenia. Indeed, physicians have reported that it is
difficult upon initial observation to determine whether somebody is
schizophrenic, or whether they are overdosing from a major stimulant. Another
factor supporting the idea of the dopamine hypothesis, in regards to
schizophrenia, was that drugs that block dopamine appear to be effective in
treating the positive symptoms of schizophrenia. However, there are some
problems with the dopamine hypothesis. And we'll discuss that further in our
next lesson, when we discuss treatments for mental disorders. Another neural
transmitter that does seem to play a role in schizophrenia is Glutamate. It
appears that Glutamate deficiencies may also explain the symptoms of
schizophrenia. That is, Glutamate is important in learning, memory, neural
processing and brain development. And it allows us to make some stimuli more
important than others. Therefore, glutamate is crucial to selective attention,
such as focusing attention on some items of information while ignoring others.
And it may explain why these individuals have difficulty with sustained
attention, cognitive control, and working memory. Now let's go back to Lauren
with the brain regions associated with schizophrenia.
