Psychiatric specifier

With seasonal pattern

Episodes show a repeated temporal relationship with a particular season and a contrasting pattern at another time of year.

Course and onset

Recurrent depressive disorderBipolar disorders

What matters now

Applies toRecurrent depressive disorder · Bipolar disorders

Deciding signalThe recurring calendar-linked course matters more than the season in which one episode happens.

Ask thisAcross years, is there a consistent seasonal onset-and-remission pattern that is not explained by seasonal stressors?

Wording outcomeMajor depressive disorder, recurrent, with seasonal pattern

Fit and exclusions

Make the specifier earn its place

Start with the deciding signal, then test chronology, competing explanations, and the effect on diagnostic wording.

When this fits

Episode onset repeatedly aligns with a particular season.
Remission or a switch in mood polarity also follows a recurring seasonal relationship.
Nonseasonal episodes do not dominate the longitudinal history.

When this may not fit

Only the current episode occurred in winter or another season.
The pattern is better explained by recurring work, anniversary, social, or environmental stressors.

Focused checks

Patient language

Clinical implication

Use the longitudinal pattern to support anticipatory monitoring and relapse planning before the usual onset period.