Anxiety disorders and anxiety symptoms in a clinic sample of seasonal and non-seasonal depressives.

Thirty-eight patients with seasonal affective disorder (SAD) were compared with 33 non-seasonal recurrent major depressives (non-SAD) who presented during the winter months for differences in the prevalence of concurrent anxiety disorders and the impact of anxiety on treatment response. SAD patients received light therapy, whereas non-SAD patients received antidepressant medications. There was no differences in the prevalence of any anxiety disorder, or on scores of anxiety on the Hamilton Rating Scale for Depression between the SAD and non-SAD groups. The presence of any anxiety disorder was associated with a better response rate in SAD patients, and an inferior response rate in non-SAD patients. The findings refute previous suggestions that anxiety is more common in SAD than in non-SAD, but suggest that the presence of anxiety may be associated with differential treatment response rates.