"Psychology Class" What happens when there is a reduction of light during the winter months?

Narrator: Listen to part of a lecture in a psychology class.
Professor:
    The National Institute of Mental Health has been doing some interesting research on chemicals in the  Q41
brain, the neurotransmitters, uh, by looking at brain images, and.., at least some of the research has
shown that the brain circuits responsible for sleep, appetite, concentration, and, uh  and mood...
they are altered during depressed states. So, basically, we’ve concluded that depression is caused by
chemical imbalances in the brain. But we’re still unclear about what triggers those imbalances in the first
place.
    Some types of depression appear to be genetically inherited, but often there’s no family history of
depression, or, conversely, a person with a family history may never develop a depressive disorder.
So... It’s a thorny problem.
    Here at the university, we’ve been studying a disorder called seasonal affective disorder. Norman  Q40
Rosenthal first identified this disorder in the mid 80s. The theory is that a decrease in light during the
long winter months may be responsible for triggering a chemical imbalance that in turn may cause  Q40
depression among those people with a predisposition to depression. Supposedly, there’s an area of the
brain called the suprachiasmatic nucleus, which is very close to the retina of the eye, so this area of the
brain responds to light by sending a signal to the pineal gland, and the signal causes the gland to suppress
the secretion of a hormone called melatonin. To make a long story short, the morn light, the less  Q42
melatonin in the blood.
    Okay, the acronym for seasonal affective disorder that’s being used in the field is S.A.D, We didn’t  Q43
come up with that, and in fact; I personally think that it’s an inappropriate way to refer to such a serious
type of depression since it sounds rather mild, and seasonal affective disorder can be a very Severe and
debilitating disorder for some people. In fact, in extreme cases, it’s life-threatening when patients
become suicidal.
    So anyway, as you can appreciate, the winter here is very dark, cold, and gray. By spring, almost
everyone is tired of the gloom, but for some people, those suffering with seasonal affective disorder, it
can be a serious problem. People with seasonal affective disorder experience deep and prolonged
depression throughout the winter months, with what looks like a spontaneous alleviation of the condition
... when spring arrives. Before the disorder was identified, it was rather a mystery for friends and family
since the depression appeared to vanish only to return several months later.
    Now, although previous research isn’t conclusive, we do know that younger people, especially  Q44
younger women, these women are at a higher risk for developing the disorder, and for being affected by
it in a more severe form. If I recall, about 75 percent of those affected are women, with a typical age of
onset about thirty years old. Other factors that contribute to the problem, apart from the long, dark days
of course, these factors include heredity and stress.
    What are the symptoms? Well, the usual spectrum of problems associated with depression-anxiety,
lack of concentration, a tendency to sleep more and eat more, cravings for food with a high
sugar content. This may be accompanied by weight gain. On the other hand, some people actually lose
their appetites and tend to lose a significant amount of weight. We also see lower energy levels and for
some people, a dull headache may accompany the problem.
    So building on the research studies that identified the symptoms of seasonal affective disorder and
the high-risk profile, we decided to undertake a longitudinal study of 120 subjects, and our research is
really focusing on therapies that might help those people affected by S.A.D. Traditionally, psychotherapy
has been used to identity and modify behaviors that contribute to depression, and it’s been some-what
successful with patients identified with seasonal affective disorder, especially when used in
combination with relaxation and stress reduction therapies. Antidepressant drug therapy has also been
proven to reduce depression in studies of people who had seasonal disorders. But we’ve been using
phototherapy almost exclusively with the subjects in our studies. It’s very simple really. We’ve supplied
each subject with a light box that provides the same type of natural lighting that would normally be shining
through the window during the spring and summer. The subjects have been instructed to turn on the
light box for two hours and then simply go about their activities in the room where the box is placed.
They’re not supposed to use the box like a sun lamp-no staring into the light, either with the eyes
closed or open. They just ignore it once it’s turned on.
    So... although we’re still evaluating our data from the first group of subjects, we have a few preliminary
findings that I’ll share with you today. First, we think that it’s probably better to be exposed to  Q45
the light box during the morning hours. Second, we’re noticing a relationship between sleep patterns
and seasonal depression, so maintaining a regular schedule for sleep seems to be a helpful therapy in
conjunction with the light treatment. We’re also fairly sure that the duration of light therapy can be modified
for individuals...Some subjects who were exposed to the light for less than two hours did very
well while others showed no evidence of relief until they reestablished the two-hour treatments. One
interesting possibility that we’re working on is whether fluorescent lights might work as well as full spectrum
light with the ultraviolet rays filtered out. In our first trials, we used UV light exclusively, but now we
have some trials underway with fluorescent light, and the results so far are encouraging I’m also happy
to report that there are few subjects who are experiencing side effects. There’s no evidence of eye damage.
We’ve been careful to filter out any potentially damaging UV rays. And, in fact, the only negative side
effect was minor headache that seemed to disappear after a few treatments.
    So... next semester, we plan to begin the second stage of our studies, and we’ll be comparing the
degree of depression on the part of subjects undergoing light treatments with control groups who will
receive either drug treatments or psychotherapy. What we really want to know is whether light treatments alone are as effective as the other options for therapy.