As the last of the leaves fall from the trees and the sun sinks lower and lower on the horizon, the spirits of some sink with it. And as the days grow shorter and shorter, many develop Seasonal Affective Disorder(SAD).

I'll never forget the first patient I saw with severe SAD. It was in the winter of 1987. I was running a Sleep Disorder Center in a New Hampshire psychiatric hospital. The first patient was a woman who was thirty -five or so. She had tried to commit suicide and almost succeeded. I was shaken. I had not realized until then that SAD could be so life threatening. She felt SAD every winter, but generally was able to hang on until her kids' February vacation from school, when the family took a vacation in sunny Florida. That immediately lifted her spirits.“What happened this year?”I asked her.“February vacation did not come until the first week of March.”We treated her with bright light. The difference was amazing. We noticed that her room became unusually full of people during the light sessions

Winter depression can be very, very severe. Even if not severe enough to require hospitalization, the psychological and physical symptoms can still be severe enough to disturb how you function and perhaps even interfere with your personal relationships.

Mood certainly changes. Some people become sad to the point of experiencing real grief at times. Others become more anxious; still others become more irritable. At times the irritability can be so extreme that feelings of violence erupt. This may be one small part of the reason why the incidence of child abuse seems to increase during the dark months.

Physical activity decreases. The person feels very lazy, often sluggish. On the other hand, appetite -especially a craving for carbohydrate -actually increases. Hypersomnia can develop; most people with SAD end up sleeping for very long hours. In many ways, it is as if a person were hibernating during the cold, dark months.

Scientists now think that SAD is a result of the decreasing hours of daylight. One of the first studies was done by South African psychiatrist Norman Rosenthal and his colleagues. The investigators found they could predict how many of the people they studied would develop SAD symptoms on the basis of how brief the daylight hours were. By the time the days close to winter solstice came, almost everyone in the study group was affected. By the end of May, almost all were back to their old selves, some unfortunately even switching into what psychiatrists call mania.

To make sure that this connection between change in mood and amount of light was more than just chance, the next step was to supply light to see if it could reverse the SAD mood. Rosenthal's team used two different kinds of light. The dimmer, yellow light had no effect. However, the brighter light that resembled actual sunlight produced a marked change in mood in most of the patients who received that treatment.

Follow  the Questions 

Mark each statement as either true (T) or false (F) according to the passage.

The author's first patient with severe SAD found that the symptoms will ease when her room was full of people.

The research on SAD discloses part of the reason why the incidence of child abuse seems to increase during the dark months.

Patients with SAD tend to sleep more and eat less.

There are evidences that people with SAD are affected by the decreasing and increasing hours of daylight.

Only one kind of light in Rosenthal's study produced a marked change in mood in most of the patients.