Predicting recovery from schizophrenia: a retrospective comparison of characteristics at onset of people with single and multiple episodes.

A retrospective study was designed to determine whether socio-demographic and clinical factors at onset, previously shown to relate to outcome, differentiated those with a single episode with no persistent symptoms of schizophrenia from other outcome groups. In a geographically determined sample of 436 people with schizophrenia spectrum disorder and a minimum followup period of at least 6 years, 68 people (15.6%) had a single episode with complete remission. The single episode group differed significantly from the rest of the sample at onset on nine variables. On a logistic regression, employment status independently predicted single episodes. Although those with single episodes differed from the rest of the sample on a number of variables, they did not differ significantly at onset from the other better outcome group (repeated episodes without persistent symptoms) on any variables with the exception of insight. Two possibilities are considered: (1) the two better outcome groups differed very little at onset but subsequent treatment or experiences accounted for the differences in outcome; or (2) important differences, not routinely assessed at onset, influenced outcome. The implications of these findings for research into the prevention of relapse in psychosis are considered.