Predictors of cognitive and functional improvement and normalization after cognitive remediation in patients with schizophrenia

Objective: Although the efficacy of cognitive remediation interventions has been demonstrated in several experimental studies on schizophrenia, few studies have investigated the predictors of response to such interventions. We were interested in determining what factors contribute to a positive outcome after cognitive rehabilitation and whether different factors are associated with different degrees of improvement in cognitive and real-world functioning in individual patients after cognitive remediation. Methods: The study sample consisted of 56 patients with schizophrenia who had completed a 6-month cognitive remediation intervention and showed different cognitive and functional outcomes. Measures of cognitive and functional amelioration after cognitive remediation were analyzed in relation to patients' clinical, neuropsychological and functional variables at baseline using logistic regression analysis. Results: Lower antipsychotic intake at baseline predicted cognitive improvement, whereas lower antipsychotic intake, severity of specific symptoms, and higher neurocognitive functioning (particularly executive functions and verbal memory) at baseline were associated with cognitive normalization after remediation treatment. Functional improvement was predicted by lower patient age and type of cognitive remediation intervention, whereas functional normalization was related to lower baseline antipsychotic intake and, at a trend level, to higher executive functioning and type of cognitive remediation intervention. Conclusion: Cognitive remediation could be more effective in younger, less disorganized, and cognitively less impaired patients, who take a smaller amount of antipsychotics. The predictive role of lower antipsychotic dosage on cognitive and functional outcome after remediation suggests either that patients with less severe illness could gain better advantage from cognitive remediation interventions or that high dose or complex antipsychotic therapy may limit the effectiveness of such interventions. © 2013 Elsevier B.V.