Cognitive remediation improves cognition and good cognitive performance increases time to relapse - results of a 5 year catamnestic study in schizophrenia patients

Background: Cognitive deficits are stable features of schizophrenia that are linked to functional outcome. Cognitive remediation approaches have been proven successful in ameliorating these deficits, although effect sizes vary considerably. Whether cognitive deficits are serious predictors of clinical outcome is less clear. Methods: Sixty patients suffering from schizophrenia were included in our sample, thirty of them received computer assisted cognitive training, and thirty received occupational therapy. For a subsample of 55 patients, who could be traced over a period of five years after the end of the cognitive remediation intervention, time until first relapse and time in psychosis were determined retrospectively from their medical records. Results: Cognitive remediation significantly improved problem solving, memory and attention with high effect sizes. Employment status, a post test verbal memory performance measure and a measure of executive functioning outperformed all other measures in the prediction of time to relapse, while allocation to treatment group outperformed all other variables in the prediction of both cognitive measures. Conclusions: Cognitive remediation of neurocognitive deficits thus makes sense in a twofold fashion: It enhances cognition directly and positively acts on clinical course indirectly via improved neurocognition.