Seasonal Pattern (Seasonal Affective)

Mood episodes show a regular temporal relationship with a particular season, with characteristic remission or change at another time of year.

Timing requirement

Longitudinal course

Pattern demonstrated over ≥2 years

Timing in context

During the last 2 years, 2 seasonal episodes must occur without nonseasonal episodes; across the lifetime, seasonal episodes substantially outnumber nonseasonal episodes.

Sources and review

Last content review: August 21, 2026