I was going to write about light therapy today, but in response to yesterday's post both Jazz and Tamara wrote that they feel worse in the summer. According to Dr. Norman Rosenthal, author of Winter Blues: Everything You Need to Know to Beat Seasonal Affective Disorder, "Studies indicate that most people in the northern United States dislike winter more than summer. When you look as far south as Florida, however, the pattern is reversed and more people dislike the summer.
"In our NIMH (National Institute of Mental Health) survey of seasonal changes in Maryland, we found about five cases of winter SAD to one case of summer SAD. While winter difficulties are more prominent in the United States and Europe, in Japan and China more people are having trouble in summer than in winter."
Dr. Rosenthal states that he and Dr. Thomas Wehr studied some people with summer SAD. Dr. Wehr postulated that "the heat of the summer might be triggering a particular patient's depressions and that the cool air and her swims in the cold, spring-fed lakes of the North might have exerted a therapeutic influence on her moods (in the fall). He suggested that temperature changes have been suggested as a cause for depression since Aristotle."
Dr. Rosenthal also mentioned that some Australian researchers had found a difference between summer SAD and winter SAD. "Whereas the patients with winter SAD feel physically slowed down by depressions, those with summer SAD are more agitated."
"Summer depressives frequently ascribe their symptoms to severe heat while winter depressives more often attribute their symptoms to lack of light."
My feeling is that there remains a tremendous amount that is unknown about SAD. A lot of the information seems to be anecdotal. Dr. Rosenthal says that while there is a very active SAD organization for consumers in England, there isn't one in the United States. (At least there wasn't one in 2006, which is when the book was published.)
Tomorrow, I will write about light therapy.