Differential improvement of negative-symptom subfactors after cognitive remediation in low-functioning individuals with schizophrenia

Abstract

Background: Negative symptoms and cognitive deficits have a substantial predictive value for functional deficits and recovery in schizophrenia. However, the relationship between negative symptoms and cognitive abnormalities is unclear possibly due to the heterogeneity of negative symptoms. This study used the model of expressive and experiential negative symptoms subfactors to decrease this heterogeneity. It examined these subfactors and cognition before and after treatment with computerized cognitive remediation training (CRT) in chronically-hospitalized individuals with psychosis and predominant negative symptoms. Methods: Seventy-eight adult participants with a DSM-IV-TR diagnosis of schizophrenia or schizoaffective disorder were enrolled in a 12-week CRT program. Assessments of demographic and illness variables, baseline and endpoint assessments of psychopathology (Positive and Negative Syndrome Scale) and cognition (MATRICS Consensus Cognitive Battery - MCCB) were conducted. Results: The baseline expressive negative subfactor was associated with Processing Speed (r = −0.352, p ≤ 0.001) and Reasoning/Problem Solving (r = −0.338, p ≤ 0.001). Following CRT, there was a significant decrease in the experiential negative subfactor (p < 0.01) but not of the expressive negative subfactor. Change in MCCB domains after CRT accounted for 51.1% and 50.2% of the variance of change in expressive and experiential negative subfactor scores, respectively. For both subfactors, Visual Learning was a significant predictor of change (p < 0.05). Conclusion: Our findings suggest that CRT has benefits for negative symptoms in very low-functioning patients and that this change may be in part mediated by change in cognitive functions after CRT. Keywords: Schizophrenia, Negative symptoms, Cognition, Expressive, Experiential, Cognitive remediation