Seasonality in panic disorder.

Following a clinical observation of increased anxiety symptoms and mood changes during winter in panic disorder patients, the Seasonal Pattern Assessment Questionnaire (SPAQ) was completed by 133 patients. Global Seasonality Scores (GSS), and the prevalence of Seasonal Affective Disorder (SAD), were significantly higher than reported in general population studies. Seasonal changes were also found in anxiety and panic attacks. These findings suggest the possibility of a common aetiology for panic disorder and SAD, that seasonality may be a far more general phenomenon in psychopathology, and that light therapy may be a useful treatment for some panic disorder patients.