A systematic review and meta-analysis of cognitive remediation in early schizophrenia

Neurocognitive impairment predicts disability in schizophrenia, making intervention theoretically attractive as a means to minimise chronic disability. Many trials confirm that cognitive remediation (CR) produces meaningful, durable improvements in cognition and functioning but fewer focus on the early stages. We systematically reviewed CR trials in early schizophrenia to determine its efficacy on global cognition, functioning and symptoms. Two reviewers independently searched electronic databases to identify randomised controlled trials investigating CR following a first episode of psychosis. Eleven trials with 615 participants were identified. Random effect models revealed a non-significant effect of CR on global cognition (effect size=0.13, 95% CI -0.04, 0.31; p0.14), p<0.05 in sensitivity analysis (effect size 0.19; CI 0.00, 0.38). One of seven neurocognitive domains showed a significant positive effect (verbal learning and memory) and five others showed borderline significant benefits. There was a significant effect on functioning (0.18; CI 0.01, 0.36; p<0.05) and symptoms (0.19; CI 0.02, 0.36; p<0.05). CR's effect on functioning and symptoms was larger in trials with adjunctive psychiatric rehabilitation and small group interventions. CR's effect sizes in early illness were smaller than those in chronic schizophrenia, perhaps because of participants' reduced scope for improvement, though trials' small number and size produces uncertain estimates of effect. However, significant benefits were seen in functioning and symptoms and moderator analyses indicate factors that may increase CR's effect. Findings here, theoretical considerations and trials in chronic schizophrenia suggest that targeting social cognition might also enhance its efficacy.