Seasonal Affective Disorder

Twenty percent of the population experiences some seasonal fluctuation in sleep and mood; up to 10 percent meet the criteria for Seasonal Affective Disorder (SAD). Although many people are affected in some way by the changing seasons, for most people, these changes do not cause problems. For people who suffer from SAD, there is a greater sensitivity to the lack of natural light in winter.


  • Weight gain
  • Drop in energy level
  • Reduction in sex drive
  • Reduction in the quality of sleep
  • Avoidance of social situations
  • Decreased concentration
  • Decreased creativity
  • Irritability
  • Inability to complete tasks
  • Change in appetite (especially craving for sweet or starchy foods)
  • Change in sleep/wake patterns (especially a tendency to oversleep)

Some of these symptoms may also stem from other seasonal stressors such as family holidays or the anniversary or recent loss of a loved one. If these symptoms are accompanied by continual feelings of deep depression, worthlessness or recurring thoughts of death or harming oneself, these are signs to seek help.

Commonly thought of as the “holiday blues” or Christmas depression, a season-long case of the “blahs” is a form of depression for some people. This condition takes on nearly debilitating proportions for some of its sufferers who may feel as though they cannot get out of bed all winter long.

Morning sunshine, so plentiful during the warmest months of the year, naturally suppresses melatonin, the body’s sleep inducing hormone. Dark winter mornings leave melatonin levels high and sufferers feeling sluggish for months at a stretch. SAD involves both biological and psychological factors.


As with any mood disorder, any treatment for SAD should be undertaken under the guidance of a qualified health professional. Exposure to bright light, known as phototherapy, has been found to be an effective method of treating SAD. Individual sensitivity to light therapy varies, so it is necessary to work with a health professional in order to determine the optimal intensity, duration, and time of day for the treatment.

Medication is generally considered less effective than light therapy for the treatment of SAD. However, it is often used to supplement light therapy or used for those who cannot tolerate light therapy. Other helpful strategies:

  • Increase amount of available indoor light by adding windows, lamps, and skylights
  • Use bright colors in decorating
  • Ask to be seated by windows at restaurants and take “window breaks” regularly at work
  • Feelings of warmth (e.g. drinking hot tea, wrapping up in a blanket) have been reported to help
  • Healthy diet and exercise habits
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