Investigating the effects of transcranial direct current stimulation (tDCS) on working memory training in individuals with schizophrenia

Cognitive impairments in schizophrenia significantly impact daily functioning and quality of life, posing a major therapeutic challenge. While both cognitive training and transcranial direct current stimulation (tDCS) have shown promise in improving cognitive function, their combined effects remain underexplored. This double-blind, sham-controlled, randomized clinical trial investigated whether adaptive working memory training (aWMT) paired with anodal tDCS to the right dorsolateral prefrontal cortex (DLPFC) enhances cognitive outcomes in schizophrenia. Twenty-eight individuals with schizophrenia or schizoaffective disorder completed ten sessions of aWMT with concurrent 2 mA anodal or sham tDCS. Cognitive improvements were assessed using the Brief Assessment of Cognition in Schizophrenia (BACS) at baseline, three days after training, and at follow-ups one month, and three months later. Clinical measures evaluated psychopathology, depression, and quality of life. Anodal tDCS significantly improved working memory performance during training, with gains partially sustained at follow-ups. Short-term transfer effects with large effect sizes were observed in the BACS, although clinical symptoms and quality of life remained unaffected. While preliminary, these findings indicate that tDCS could support cognitive training outcomes in schizophrenia. Larger randomized controlled trials are needed to confirm transfer effects and determine the long-term benefits of this approach. If proven effective, integrating tDCS into cognitive remediation therapies could represent an innovative strategy to address cognitive deficits in schizophrenia.