The impact of aging, cognition, and symptoms on functional competence in individuals with schizophrenia across the lifespan.

Abstract

Life expectancy in individuals with schizophrenia continues to increase. It is not clear whether cognitive deficits associated with schizophrenia remain as strong predictors of function in older and younger individuals. Thus, we assessed the relationship between cognition and functional competence in individuals with schizophrenia across 7 decades of life. We analyzed data obtained in 232 community-dwelling participants with schizophrenia (age range: 19-79 years). Cognition was assessed using the Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus Cognitive Battery. Functional competence was assessed using the UCSD Performance-based Skills Assessment, which includes measures of Comprehension and Planning of Recreational Activities Skills, Financial Skills, Communication Skills, Transportation Skills, and Household Management Skills. To assess the effects of Global Cognition on functional competence, we performed hierarchical multivariate linear or logistic regression analyses controlling for age, education, gender, and negative symptoms. Participants' mean age was 49.1 (SD = 13.2, range = 19-79 years), 161 (69%) were male, and 55 (24%) were aged ≥60. Global Cognition was a predictor of Comprehension and Planning Skills (Exp(β) = 1.048), Financial Skills (Exp(β) = 1.104), Communication Skills (ΔR (2) = .31) and Transportation Skills (Exp(β) = 1.066), but not Household Management Skills after adjusting for age, education, gender, and negative symptoms of schizophrenia. Cognition remains a strong predictor of functional competence across the lifespan. These findings suggest that treating cognitive impairment associated with schizophrenia could improve individuals' function independent of their age.