BACKGROUND The risk of recurrence in affective disorder has been found to increase with each new episode. It is unclear whether it is universal without regard to gender, age and type of disorder.
METHOD Survival analysis was used to estimate the risk of recurrence in a case-register study including all hospital admissions with primary affective disorder in Denmark from 1971-1993. In this period 20,350 first-admission patients had been discharged with a diagnosis of affective disorder, depressive or manic/cyclic type.
RESULTS The risk of recurrence increased with the number of previous episodes regardless of the combination of gender, age and type of disorder. Initially in the course of illness, unipolar and bipolar women experienced an equal greater risk of recurrence than men. The risk of recurrence after the first episode was increased for middle-aged and older unipolar women compared with the risk for younger women, while after all other episodes younger age at first episode increased the risk of recurrence.
CONCLUSIONS The course of severe unipolar and bipolar disorder seems to be progressive in nature irrespective of gender, age and type of disorder.