Seasonal Affective Disorder (SAD) is a type of depression that follows the seasons. Individuals suffering from SAD will suffer from symptoms of depression at a certain time of the year, every year. Most people who suffer from Seasonal Affective Disorder usually experience depressive symptoms during the late fall and winter months. The Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) describes Seasonal Affective Disorder not as a separate mood disorder but as a “specifier,” referring to the seasonal pattern of major depressive episodes that can occur within major depressive and bipolar disorders.
Criteria for Seasonal Pattern Specifiers
- Regular temporal relationship between the onset of major depressive episodes and a particular time of the year (unrelated to obvious season-related psychosocial stressors)
- Full remissions (or a change from depression to mania or hypomania) also occur at a characteristic time of the year
- Two major depressive episodes meeting criteria A and B in last two years and no nonseasonal episodes in the same period
- Seasonal major depressive episodes substantially outnumber the nonseasonal episodes over the individual’s lifetimeDiagnostic and statistical manual of mental disorders. 4th ed. Washington, D.C.: American Psychiatric Association, 1994:390. Copyright 1994.
Seasonal Affective Disorder is related to the amount of light present at different times of the year. SAD, also known as winter depression, is the body reaction to the lack of adequate sunlight. An estimated 4 to 6% of the U.S. population suffer from winter depression and an additional 10 to 20% experience mild Seasonal Affective Disorder. This condition is more common in women than in men at a 4:1 ratio. People who suffer from this condition may need light therapy.
Light therapy is process where the individual is exposed to artificial sunlight for a short period of time each day through the late fall and winter months. Tanning beds should not be used to treat Seasonal Affective Disorder since the light source is high in ultra violet rays that can cause damage to eyes and skin. There are few side effects related to proper light therapy. Some of the side effects may include eyestrain, headache, irritability and inability to sleep if treated late in the day, and fatigue.