Prevalence of seasonal changes in mood and behavior during the winter months in central Texas.

The Seasonal Pattern Assessment Questionnaire (SPAQ) was administered to a sample of students, faculty, and staff at a large state university in central Texas. Estimated prevalence rates of winter seasonal affective disorder (SAD) and subsyndromal winter SAD (S-SAD) derived from their SPAQ responses were considerably higher than expected, given the relatively low latitude of the area. Generally consistent with earlier findings, women experienced greater seasonal change in mood and behavior than men, and older individuals experienced less seasonal change than younger individuals.