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Seasonal Affective Disorder

  1. Kathryn A. Roecklin,
  2. Kelly J. Rohan

Published Online: 30 JAN 2010

DOI: 10.1002/9780470479216.corpsy0830

Corsini Encyclopedia of Psychology

Corsini Encyclopedia of Psychology

How to Cite

Roecklin, K. A. and Rohan, K. J. 2010. Seasonal Affective Disorder. Corsini Encyclopedia of Psychology. 1–2.

Author Information

  1. University of Vermont

Publication History

  1. Published Online: 30 JAN 2010


Seasonal affective disorder (SAD) is recurrent major depression with onset and full remission (or change to hypomania or mania) during characteristic seasons. For the vast majority of SAD cases, major depressive episodes begin in the fall or winter and remit or change in the spring. SAD is diagnosed as major depressive, bipolar I, or bipolar II disorder with a seasonal pattern in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR; American Psychiatric Association, 2000). Among SAD patients, major depressive disorder is the most common diagnosis, bipolar II is less common, and bipolar I is rare. The average age of onset for SAD is 23 to 27 years, but SAD has also been observed in children and adolescents (Magnusson & Partonen, 2005).


  • seasonal affective disorder;
  • symptoms;
  • etiology;
  • treatment