Many injured workers seek outdoor employment because they feel they must be in the sun and fresh air. When offered indoor factory/production work, they become lethargic and irritable.
Some people suffer from symptoms of depression during the winter months, with symptoms subsiding during the spring and summer months. This may be a sign of Seasonal Affective Disorder (SAD). SAD is a mood disorder associated with depression episodes and related to seasonal variations of light.
SAD was first noted before 1845, but was not officially named until the early 1980_s. As sunlight has affected the seasonal activities of animals (i.e., reproductive cycles and hibernation), SAD may be an effect of this seasonal light variation in humans.
As seasons change, there is a shift in our _biological internal clocks_ or circadian rhythm, due partly to these changes in sunlight patterns. This can cause our biological clocks to be out of _step_ with our daily schedules. The most difficult months for SAD sufferers are January and February, and younger persons and women are at higher risk.
_ regularly occurring symptoms of depression (excessive eating and sleeping, weight gain) during the fall or winter months.
_ full remission from depression occur in the spring and summer months.
_ symptoms have occurred in the past two years, with no nonseasonal depression episodes.
_ seasonal episodes substantially outnumber nonseasonal depression episodes.
_ a craving for sugary and/or starchy foods.
Possible Cause of this Disorder:
Melatonin, a sleep-related hormone secreted by the pineal gland in the brain, has been linked to SAD. This hormone, which may cause symptoms of depression, is produced at increased levels in the dark. Therefore, when the days are shorter and darker the production of this hormone increases.
Phototherapy or bright light therapy has been shown to suppress the brain_s secretion of melatonin. Although, there have been no research findings to definitely link this therapy with an antidepressant effect, many people respond to this treatment. The device most often used today is a bank of white fluorescent lights on a metal reflector and shield with a plastic screen. For mild symptoms, spending time outdoors during the day or arranging homes and workplaces to receive more sunlight may be helpful. One study found that an hour_s walk in winter sunlight was as effective as two and a half hours under bright artificial light.
If phototherapy does not work, an antidepressant drug may prove effective in reducing or eliminating SAD symptoms, but there may be unwanted side effects to consider.