Seasonal Affective Disorder (SAD)

Winter Blues, Depression, or Just Your Imagination?

The concept of Seasonal Affective Disorder (SAD), a type of depression which can be triggered by changes in environmental light levels, dates back to Hippocrates who wrote about the changes of seasons producing diseases; although he was considering mainly a change in temperature versus light exposure and levels of exposure. Seasonal Affective Disorder received more prominence and acceptance as a type of depression when Rosenthal et al published a paper describing a group of patients with winter depression, Seasonal Affective Disorder, in 1984.

One finding in Rosenthal's report was the benefit of light therapy in relieving patient's symptoms of winter depression sometimes labeled winter SAD. So how do we determine whether we have Seasonal Affective Disorder, the "winter blues," depression, or if we're just imagining symptoms? Is Seasonal Affective Disorder a real condition? If so, is it treated like other types of depression?

Seasonal Affective Disorder is not recognized in ICD-10 (International Classification of Diseases) as a specific disorder, but it is in the DSM-IV (Diagnostic and Statistical Manual of Mental Disorders) as 'recurrent depressive episodes with a seasonal pattern.' Some psychiatrists disparage the existence of Seasonal Affective Disorder, either winter SAD or summer SAD, as a separate disorder and believe the fact depression occurs seasonally is irrelevant in terms of overall diagnosis and treatment. In other words, some professionals contend that the seasonal mood changes are merely part of the patient's overall depression, not a separate condition referred to as Seasonal Affective Disorder.

About 16 percent of Americans will experience a major depression sometime during their life. Annually, approximately 17 million American adults will suffer from some form of depression. Nearly a half million people in the United States may have winter depression and an additional 10 to 20 percent of the population experiencing mild SAD.