Seasonal Affective Disorder: What are the symptoms?

Although seasonal affective disorder (SAD) can strike in summer, it’s most common throughout fall and winter — here are the symptoms to look out for.

depressed woman sitting near window and looking at autumn landscape outside in rainy day.
(Image credit: Getty Images)

Heard of the term Seasonal Affective Disorder (SAD)? Although the exact cause of this type of depression is unknown, SAD has been linked to the changing of the seasons. 

SAD is most common in the darker months of the year, when exposure to sunlight is decreased, vitamin D levels are reduced and there is an imbalance of serotonin and melatonin levels. According to a review in the The Physician and Sportsmedicine journal, SAD affects one to 10 percent of the population every year.

Laura Geggel
Managing Editor

Laura is the managing editor at Live Science. She also runs the archaeology section and the Life's Little Mysteries series. Her work has appeared in The New York Times, Scholastic, Popular Science and Spectrum, a site on autism research. She has won multiple awards from the Society of Professional Journalists and the Washington Newspaper Publishers Association for her reporting at a weekly newspaper near Seattle. Laura holds a bachelor's degree in English literature and psychology from Washington University in St. Louis and a master's degree in science writing from NYU.

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