LACK OF GENERALIZATION FROM A HIGH-DOSE, WELL-POWERED RANDOMIZED CONTROLLED TRIAL OF WORKING MEMORY-FOCUSED TRAINING FOR SCHIZOPHRENIA

Background: Cognitive defcits contribute to the functional disability associated with schizophrenia. Cognitive training has shown promise as a method of intervention; however, there is considerable variability in the implementation of this approach. The aim of this study was to test the effcacy of a high dose of cognitive training that targeted working memory‐related functions. Methods: A randomized, double blind, active placebo‐controlled, clinical trial was conducted with 80 outpatients with schizophrenia (mean age 46.44 years, 25% female). Patients were randomized to either working memory‐based cognitive training or a computer skills training course that taught computer applications. In both conditions, participants received an average of 3 hours of training weekly for 16 weeks. Cognitive and functional outcomes were assessed with the MATRICS Consensus Cognitive Battery, N‐Back performance, 2 measures of functional capacity (UPSA and SSPA) and a measure of community functioning, the Social Functioning Scale. Results: An intent‐to‐treat analysis found that patients who received cogni‐tive training demonstrated signifcantly greater change on a trained task (Word N‐Back), F(78) = 21.69, P <.0001, and a novel version of a trained task (Picture N‐Back) as compared to those in the comparison condition, F(78) = 13.59, P =.002. However, only very modest support was found for generalization of training gains. A trend for an interaction was found on the MCCB Attention Domain score, F(78) = 2.56, P =.12. Participants who received cognitive training demonstrated signifcantly improved performance, t(39) = 3.79, P =.001, while those in computer skills did not, t(39) = 1.07, P =.37. Conclusion: A well‐powered, high‐dose, working memory focused, computer‐based, cognitive training protocol produced only a small effect in patients with schizophrenia. Results indicate the importance of measuring generalization from training tasks in cognitive remediation studies. Computer‐based training was not an effective method of producing change in cognition in patients with schizophrenia.