“Seasonal affective disorder (also called SAD) is a type of mood disorder that occurs at the same time every year. If you’re like most people with seasonal affective disorder, your symptoms start in the fall and may continue into the winter months, sapping your energy and making you feel moody. Less often, seasonal affective disorder causes depression in the spring or early summer.

Treatment for seasonal affective disorder includes light therapy (phototherapy), psychotherapy and medications. Don’t brush off that yearly feeling as simply a case of the “winter blues” or a seasonal funk that you have to tough out on your own.”

Complete article, including symptoms, causes and treatment can be found at the Mayo Clinic website Seasonal affective disorder (SAD)

SAD may be associated with either depressive or bipolar symptoms. There’s evidence that the risk of experiencing SAD is related to where a person lives. In New Hampshire 9.7% of the population report symptoms but only 1.4% of Florida residents. Research has shown that bulimia, anxiety and other psychiatric disorders may also be effected by the change in seasons.

Did you know that children can also be effected by SAD? From the American Academy of Pediatrics: Winter Blues – Seasonal Affective Disorder and Depression