Background Seasonal changes in mood and behavior are considered to be common in the general population and in patients with psychiatric disorders. However, in several studies this seasonality could not be demonstrated. The present study examined self‐attributed seasonality of depressive symptoms among patients with a lifetime diagnosis of a depressive disorder (D), an anxiety disorder (A), a comorbid depressive and anxiety disorder (DA), and healthy controls (HC). Methods The CIDI was used to establish diagnoses according to DSM‐IV criteria in 2,168 participants of the Netherlands Study of Depression and Anxiety (NESDA). The Seasonal Pattern Assessment Questionnaire (SPAQ) was administered to assess variation in mood and behavior. Results Of the 2,168 participants 53.5% reported seasonality of mood. Highest percentages of low mood were seen in the winter months. Although all groups showed this pattern of lowered mood during the winter months, D, A, and DA were significantly (P < .001) more likely to experience seasonality is this respect. This was also shown for seasonal changes in energy, social activities, sleeping, eating, weight and for the Global Seasonality Score. A limitation of this study was the cross‐sectional design. Conclusions Seasonal variation in mood and behavior was demonstrated for both participants with a lifetime diagnosis of depression and/or anxiety disorder and for healthy controls, but patients with anxiety and/or depression were more likely to experience this seasonal variation. Clinicians should take into account that the time of the year could influence the feelings of well‐ and ill‐being of their patients.