Many people around the world have depressive episodes during specific seasons. Those who have minimal mental health issues throughout the rest of the year may experience symptoms of depression during a single season. In 1984, Norman Rosenthal described and named this depression seasonal affective disorder or SAD. He also pioneered light therapy as an effective means of treating the symptoms. Many people initially disagreed with the existence of seasonal affective disorder, though now it appears as a mood disorder subset in the Diagnostic and Statistical Manual of Mental Disorders, the DSM.


1. Updated Definition

Since its discovery in 1984, experts have debated the existence of SAD. Some people believed the depressive symptoms experienced during winter were not proof of a disorder but rather that the dark and cold weather set the expectation of being sad. However, studies confirm the symptoms exist and affect people during any season. Certain individuals may experience the symptoms during spring or summer rather than fall and winter. The fourth and fifth editions of the DSM define SAD as a mood disorder subtype and recommend it as an added descriptor for 2people who experience a pattern of major depressive episodes or patients with bipolar disorder.

definition seasonal affective disorder

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