Determinants of everyday outcomes in schizophrenia: the influences of cognitive impairment, functional capacity, and symptoms

Abstract

Deficits in everyday living skills and social skills are associated with the pervasive disability seen in schizophrenia. Cognitive impairments are determinants of these skills deficits and it is known that positive and negative symptoms add to the influence of cognitive impairments for prediction of real-world outcomes. This study examined the relative importance of cognitive impairments measured with a neuropsychological battery, performance-based measures of social and everyday living skills, and positive and negative symptoms for the prediction of real-world outcomes in social and residential domains. In contrast to most previous studies, we examined the importance of individual symptoms, as well as total subscale scores, for predicting clinician rated outcomes in 194 older outpatients with schizophrenia. Symptoms were rated with the Positive and Negative Syndrome Scale; everyday living skills were measured by the UCSD Performance-based Skills Assessment; and social skills were measured with the Social Skills Performance Assessment. For prediction of real-world social outcomes, blunted affect and passive-apathetic social withdrawal accounted for all of the predicted variance, while social competence and cognitive impairments did not enter the final equation. For residential functioning, everyday living skills were the most important predictor, followed by lack of spontaneity. The positive symptoms of hallucinatory behavior and suspiciousness also predicted real-world residential outcomes. These results suggest that real-world disability is the product of a complex array of ability deficits and symptoms, indicating interventions will need to be carefully targeted. For social and everyday living outcomes, variance accounted for by the entire array of predictive variables was less than 40%, suggesting that other factors, such as social and cultural influences, are involved as well.