Cognitive rehabilitation in schizophrenia: a quantitative analysis of controlled studies

Rationale. Cognitive rehabilitation is now recognized as an important tool in the treatment of schizophrenia, and findings in this area are emerging rapidly. There is a need for a systematic review of the effects of the different training programs. Objectives. To review quantitatively the controlled studies on cognitive rehabilitation in schizophrenia for the effect of training on performance on tasks other than those practiced in the training procedure. Methods. A meta-analysis was conducted on 12 controlled studies of cognitive rehabilitation in schizophrenia taking into account the effects of type of rehabilitation approach (rehearsal or strategy learning) and duration of training. Results. The mean weighted effect size was 0.45, with a 95% confidence interval from 0.26 to 0.64. Effect sizes differed slightly, depending on rehabilitation approach, in favor of strategy learning, but this difference did not reach statistical significance. Duration of training did not influence effect size. Conclusions. Cognitive rehabilitation can improve task performance in patients with schizophrenia and this effect is apparent on tasks outside those practiced during the training procedure. Future studies should include more real-world outcomes and perform longitudinal evaluations.