Seasonal affective disorder* is a form of depression also known as SAD, seasonal depression or winter depression. In the Diagnostic Manual of Mental Disorders (DSM-5), this disorder is identified as a type of depression – Major Depressive Disorder with Seasonal Pattern.
People with SAD experience mood changes and symptoms similar to depression. The symptoms usually occur during the fall and winter months when there is less sunlight and usually improve with the arrival of spring.
SAD is more than just “winter blues.” The symptoms can be distressing and overwhelming and can interfere with daily functioning. However, it can be treated.
It is more common among women than men.
SAD has been linked to a biochemical imbalance in the brain prompted by shorter daylight hours and less sunlight in winter. As seasons change, people experience a shift in their biological internal clock or circadian rhythm that can cause them to be out of step with their daily schedule.
SAD is more common in people living far from the equator where there are fewer daylight hours in the winter.
Common symptoms of SAD include fatigue, even with too much sleep, and weight gain associated with overeating and carbohydrate cravings.
SAD symptoms can vary from mild to severe and can include many symptoms similar to major depression.
