Determinants of long-term outcome in psychotic disorders: a 13-year prospective study

Abstract

Motivations The growing interest in the investigation of longitudinal course and outcome of psychotic disorders grew from the Kraepelinian view of schizophrenia, which was considered a disease with progressive downhill course. With emerging evidence-based findings suggesting outcome heterogeneity, prospective studies have strived to identify factors influencing the course and outcome. The paucity of prospective long-term studies has prevented us from knowing the enduring impacts of predictors.

Using a prospective cohort of 153 psychosis patients, the study aimed to determine the outcome of global functioning, remission, functional recovery, and recovery at 13 years following the first-episode psychosis. Prognostic values of a range of baseline and early outcome predictors were examined. Specific research interests included the explorations of the enduring impact of duration of untreated psychosis (DUP), the longitudinal relationship between neurocognition and functional outcome, and the added predictive ability of early outcome predictors.

Methods This study attempted to follow up the 153 patients at 13 years following their first episode onset of psychosis. Prior investigations collected a comprehensive profile of demographics, premorbid adjustment, clinical symptoms, and neurcognition at baseline. Early outcomes at 3 years including remission, relapse, primary negative symptoms, and unemployment were also ascertained. In this current investigation, living subjects were invited to an interview in order to assess their outcomes of global functioning, remission, functional recovery, and recovery at 13 years. Appropriate regression models were applied to identify predictors of long-term outcomes. Standardized mortality ratios (SMRs) for all-cause mortality and suicide were also determined.

Results Ninety-six patients were successfully interviewed. Their mean (s.d.) score of global functioning was 64.3 (16.5). Considerable proportions of patients fulfilled criteria for remission (47%), functional recovery (33%), and recovery (16%) at 13 years. Higher level of global functioning was predicted by a married status at study entry and being in remission and employed at 3 years. Remission was predicted by a shorter DUP and better premorbid social adjustment. Functional recovery was predicted by better premorbid social adjustment, better baseline visual memory, and being employed at 3 years. No baseline and early outcome predictors of recovery could be identified. Addition of early outcome predictors significantly increased the variance explained for global functioning and improved model discrimination between patients who had functional recovery and those who had not. SMRs for all-cause mortality and suicide were 6.07 and 24.80, respectively.

Discussion A prolonged DUP may intensify the progression of negative symptoms and lead to less likelihood of remission. The study has confirmed the enduring adverse impact of DUP but its reversibility is still in doubt. As the significance of visual memory in functional outcome has not received consistent support from literature, more prospective long-term studies are in need to re-examine the relationship. Early outcome predictors appear to be more relevant to functional outcome than clinical outcome.

Discussion A prolonged DUP may intensify the progression of negative symptoms and lead to less likelihood of remission. The study has confirmed the enduring adverse impact of DUP but its reversibility is still in doubt. As the significance of visual memory in functional outcome has not received consistent support from literature, more prospective long-term studies are in need to re-examine the relationship. Early outcome predictors appear to be more relevant to functional outcome than clinical outcome.