Epidemiological findings of seasonal changes in mood and behavior. A telephone survey of Montgomery County, Maryland. Arch Gen Psychiatry 46: 823–833

\s=b\Patterns of seasonal changes in mood and behavior in Mont-gomery County, Maryland, were evaluated in randomly selected household samples by lay interviewers using a telephone ver-sion of the Seasonal Pattern Assessment Questionnaire. The method for selecting the sample unit was random-digit dialing. We found that 92 % of the survey subjects noticed seasonal changes of mood and behavior to varying degrees. For 27 % of the sample seasonal changes were a problem and 4.3 % to 10 % of subjects, depending on the case-finding definition, rated a de-gree of seasonal impairment equivalent to that of patients with seasonal affective disorder. The seasonal pattern of "feeling worst " exhibited a bimodal distribution with a greater winter and a substantially lower summer peak (ratio, 4.5:1). Younger women who have a problem with seasonal changes and who feel worse on short days tended to exhibit the highest seasonality scores. I