Clinical course and outcome of cycloid psychotic disorder: a three-year prospective study.

The course and outcome of cycloid psychotic disorder was explored by means of a prospective three-year follow-up of a sample of patients fulfilling the diagnostic criteria for the disorder provided by Perris & Brockington, compared to patients with a diagnosis of affective or schizoaffective disorder. The most striking difference between cycloids and affectives was the lack of manic episodes during the follow-up period in the former group. Moreover, the mean age at onset was lower in cycloids. No difference between these patient groups was observed with regard to outcome. Compared to schizoaffectives, cycloids showed several differences in the clinical picture during the index episode, and their symptomatological pattern was more consistent from one episode to another during the follow-up. Moreover, the outcome of cycloids was significantly more favourable than that of schizodepressives.