A mood disorder characterized by mental depression, related to a certain season of the year, often winter. Feeling sad or depressed during the fall and winter due to decreasing amounts of daylight.
It is characterized by annual episodes of depression during fall or winter that remit in the spring or summer.
SAD can occur alone, or can make symptoms of depression worse. Mild symptoms respond to spending time outdoors during the day or arranging homes and workplaces to receive more sunlight.
A cyclically recurring mood disorder characterized by depression, extreme lethargy, increased need for sleep, hyperphagia, and carbohydrate craving; it intensifies in one or more specific seasons, most commonly the winter months, and is hypothesized to be related to melatonin levels.
Also known as: The Winter Blues, SAD
ADAM Illustrated Medical Encyclopedia. Seasonal affective disorder. <http://adam.about.com/encyclopedia/001532.htm>
Dorland's Illustrated Medical Dictionary. Disorder. Whitehouse Station, N.J.: Merck