Prediction of a single psychotic episode: a 7.5-year, prospective study in first-episode psychosis

Around 20% of patients who suffer from psychosis will experience a single psychotic episode (SPE), but relatively little is known about the characteristics and predictors for this group of patients. This study sought to: 1) characterise the subgroup of first-episode psychosis (FEP) patients who experienced a SPE over a 7.5-year follow-up; and 2) to identify significant predictors for this subgroup independent of potential confounders.

A representative sample of 413 FEP patients treated at a specialist early psychosis service were assessed at baseline and followed-up for 7.5 years. Binary logistic regression models were employed to investigate univariate and adjusted associations between baseline predictors and experiencing a SPE. Results were adjusted for the influence of known prognostic factors for psychosis.

Follow-up data was available for 274 participants. Forty-six (16.5%) achieved clinical remission and experienced no recurrence over the follow-up period. Duration of untreated psychosis (DUP) shorter than 60 days (OR=3.89, p=0.007), more rapid response to antipsychotic treatment (OR=0.33, p=0.019) and no parental loss (OR=5.25, p=0.045) significantly predicted a SPE. The association remained significant after controlling for potential confounders.

Early treatment (within two months of onset of psychotic symptoms) and social support significantly reduce vulnerability to subsequent psychotic episodes. Future studies need to investigate the interplay between biological factors (i.e. sensitized dopaminergic system), environmental variables (i.e. exposure to trauma, stigma and discrimination), and psychological attributes (i.e. cognitive schemata) in order to elucidate the processes underlying the vulnerability to recurrent psychotic episodes.