Seasonal Affective Disorder and Phototherapy

While theories linking seasonality and affective episodes date back to the time of Hippocrates, it is only recently that the idea has gained widespread acceptance. The recognition that melatonin could be suppressed by bright light, the delineation of seasonal affective disorder (SAD) as a syndrome with distinct clinical and therapeutic implications, and the efficacy of bright light in the treatment of this condition, were all important steps in this regard. The therapeutic value of bright light in SAD closely aligns the biology of the disorder with its treatment and introduces into psychiatry an exciting new therapeutic modality.
SEASONAL AFFECTIVE DISORDERS AND PHOTOTHERAPY brings together the latest research in four key areas:
* Diagnostic profile of SAD, epidemiological issues, and specific clinical applications of light
* Animal models of seasonality
* Normal human seasonality and its relationship to psychiatric disorders
* Biological mechanisms subserving light treatment
Introductory chapters consider the different profiles of SAD and detail outcome studies across the Northern Hemisphere. Important questions are addressed about summer depression, with and without winter depression, as well as seasonality and SAD in children and adolescents. Also included are current prevalence data on SAD--several reports in this volume suggest it may occur in approximately 5% of the population with subclinical disturbances present in even more individuals.
Reports on seasonal changes in the normal population consider whether the mood and personality changes observed in SAD are extremes of normal human seasonality and whether the disorder's pathophysiology is actually on acontinuum with a range of biological seasonal changes found in the general population. A neurological theory is presented that maps the basic systems involved in mobilizing behavior and engaging the organism with its environment. The theory is then applied to seasonal chang