Frequency of seasonal affective disorder among individuals seeking treatment at a northern Canadian mental health center.

The frequency of seasonal affective disorder (SAD) was examined in clients receiving treatment for recurrent mood disturbances in a northern Canadian site. Approximately one-fifth of these individuals were identified as having SAD when file histories and a statistical criterion were used as the basis for assessment. The failure to find a higher prevalence rate at this latitude may be due to other studies' reliance on client self-report, a tendency for individuals with SAD to relocate south, or a greater tendency for clients with SAD to be seen by general practitioners and alcohol treatment centers in the north.