SAD

         When winter arrives, some people get sad, even suicidal.
         Doctors have recently started to study the causes of a medical disorder that they have appropriately named SAD, or Seasonal Affective Disorder. People who suffer from SAD become very depressed during the winter months. Their depression appears to be the result of a decrease in the amount of sunlight they are exposed to. Doctors theorize that decreased sunlight affects the production of melatonin, a hormone manufactured in the brain, and serotonin, a chemical that helps transmit nerve impulses. Depression may result from the ensuing imbalance of these two substances in the body. Also, doctors believe that a decrease in the amount of sunlight the body receives may cause a disturbance in the body's natural clock which cloud, in turn, result in symptoms such as lethargy, oversleeping, weight gain, anxiety, and irritability-all signs of depression.
        Since absence of light seems to be the cause of this disorder, a daily dose of light appears to be the cure. Doctors advise patients to sit in front of a special light box that simulates natural light for a few hours everyday.
        In conclusion, the depressive effect of low sunlight levels may help explain the high suicide rate in the Scandinavian countries, and more importantly, it may suggest a remedy. When the days grow short, turn on the lights.