Functional outcome in psychosis is better determined by negative symptoms than cognitive impairment

Abstract

Introduction

Cognitive impairment is considered the best predictor of functional outcome in psychosis. However, the nature of this relationship still remains to be determined.

Objective

To ascertain the relationship of negative symptoms and cognitive impairment with functional outcome in psychosis.

Methods

Ninety patients with a DSM-IV psychotic disorder diagnosis and 65 healthy controls were included in the study. We assessed the predominant negative symptoms over the course of illness with the Comprehensive Assessment of Symptoms and History (CASH). Functional outcome was assessed with the Specific Levels of Functioning (SLOF). Cognition was assessed with a set of neuropsychological tests, which were normalised to z-scores (regarding controls’ performance). Then, a Global Cognition Index (GCI) was obtained as a mean of the cognitive domains assessed: processing speed, attention, verbal and visual memory, executive functions, working memory and social cognition. We divided the sample in four groups, considering the presence/absence of negative symptoms (cut-off point of 2 in the CASH), and the presence/absence of cognitive impairment (considering a GCI z-score of–1 as cut-off point). We performed a MANOVA to compare the 4 groups’ functional outcome scores.

Results

Fig. 1 shows the significant differences between groups regarding functional outcome.

Conclusions

The combination of negative symptoms and cognitive impairment has deleterious effects over functionality, but negative symptoms alone are related to functional outcome, independently of cognitive impairment.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Fig. 1