IS HYPERSOMNOLENCE A FEATURE OF SEASONAL AFFECTIVE-DISORDER

We examined hypersomnolence as experienced among individuals meeting s tandardized diagnostic criteria for Seasonal Affective Disorder (SAD). Data were available from 115 individuals attending a mood disorders c linic specializing in treatment of this disorder. Three modes of asses sment were employed: retrospective self-reports (Seasonal Patterns Ass essment Questionnaire), cross-sectional interviews (Standardized Inter view Guide for the Hamilton Depression Scale, SAD Version), and prospe ctive sleep diaries. Results indicated that self-reported total hours of sleep varied significantly across the seasons, with longest sleep o ccurring in winter and shortest sleep in summer. Seasonal sleep change s, as indicated by the SPAQ did not correlate significantly, however, with severity of depressive symptoms as indicated by the Hamilton scal e. Multiple regression analyses indicated that only social activity le vels (one of seven SPAQ items) was significantly and uniquely related to the severity of depression. When data obtained by the three instrum ents were compared, self-reported hours of sleep (whether measured by SPAQ or Hamilton interview) were significantly higher than indicated b y prospective sleep diaries. We conclude that hypersomnolence may not be a central feature of SAD and that the validity of the SPAQ as an in dex of this disorder requires further investigation.