Seasonal affective disorder (SAD) and phototherapy have recently been the subject of a great deal of interest in the psychiatric literature. First described in 1984 (I), SAD is now defined as "a cyclic illness characterized by recurrent episodes of fall/winter depression alternating with periods of spring/summer euthymia (normal mood) or hypomania (mild elation and behavioral activation)" (2) . Recent findings indicate that there may be at least two additional patterns of seasonal depressions, one characterized by annual summer depressions with euthyrnic, hypomanic or manic symptoms in the winter, and the other characterized by depressive episodes occurring in both winter and summer (3-6).
Pichot, MD, J. Thomas and Jensen, MD, Peter S.
"Seasonal Affective Disorder: SAD or Fad?,"
Jefferson Journal of Psychiatry: Vol. 7
, Article 7.
Available at: http://jdc.jefferson.edu/jeffjpsychiatry/vol7/iss1/7