Schizophrenia is among the most disabling illnesses of adults in the world. With illness onset typically occurring in young adulthood, individuals with schizophrenia often struggle to establish and maintain social and work roles in the community. In recognition of the profound disability associated with schizophrenia, the Veteran?s Health Administration has prioritized provision of mental health care services to adults with severe and persistent mental illnesses. The President?s New Freedom Commission called for the development of mental health care services that focus on ?increasing consumer?s ability to successfully cope with life challenges, on facilitating recovery, and on building resilience.? The proposed intervention study is designed to enhance cognition, and ultimately, psychosocial functioning in patients. The cognitive dysfunction associated with schizophrenia has been found to be one of the strongest predictors of how well patients do in the community. The primary aim of the proposed study is to evaluate the efficacy of a novel pairing of two therapeutic interventions designed to restore cognitive functioning in patients with schizophrenia. Presently, cognitive remediation, a computer-based intervention that exercises cognitive abilities, is the approach to intervention that has shown the most success in changing cognitive performance in patients with schizophrenia. While gains are made with this approach to intervention, the impact has been modest, and the intensity of training regimens required by this approach may be a barrier that limits widespread use of this intervention. Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that has been found to temporarily facilitate learning and to enhance cognitive performance. The proposed study will examine these two techniques used in combination to enhance cognition and psychosocial functioning in patients with schizophrenia. To accomplish this goal, 100 patients with schizophrenia will be randomized to cognitive remediation paired with either tDCS or a sham condition. In both conditions participants will receive computer-based cognitive training and metacognitive strategy training three times a week for 16 weeks. The cognitive training protocol proposed in this study is focused on exercising working memory processes and has been found to be effective in producing change in this domain. Participants in the tDCS condition will receive 20 minutes of 1 mA stimulation concurrent with training. Participants in the sham condition will receive 30 seconds of stimulation to simulate the experience of tDCS. We hypothesize that, as compared to participants in the sham condition, patients who receive cognitive remediation with tDCS will demonstrate significantly greater change on neuropsychological measures of working memory, related cognitive functions, functional capacity, and community functioning. A second study goal is to examine the stability of intervention-induced change in cognition. Participants will be re-assessed 6 weeks and 6 months (26 weeks) after treatment termination to examine the stability of intervention induced change. We hypothesize that training induced changes in cognition will be stable and that participants who receive cognitive training with tDCS will maintain the predicted between-group difference throughout the follow up period. In addition, this study will examine in an exploratory manner whether individual differences in performance on the cognitive training are predictive of magnitude and breadth of intervention-induced change. Last, participant experience of cognitive remediation with tDCS and sham will be closely assessed to identify reactions to the intervention procedures that could be a barrier to implementation in clinical practice. Participants are expected to report that the procedures are tolerable, worthwhile, and enjoyable. Achieving these objectives will inform intervention development efforts by evaluating the efficacy and acceptability of a safe, non-invasive, and affordable adjunct to cognitive remediation.
Given that the vast majority of patients with schizophrenia are cognitively impaired, there is significant need for effective and efficient interventions that target this aspect of the illness. The functional disability associated with cognitive impairment in this population is one of the most distressing aspects of the illness to both patients and family members, and improvement in psychosocial functioning is frequently a goal that both patients and family members are motivated to work toward. Development of a cognitively enhancing intervention would fill a gap in the current mental health services offered to this population. If the study hypotheses are supported, the proposed treatment study would provide empirical support for the efficacy of a non-invasive approach to treatment that has the potential to restore cognitive and psychosocial functioning in schizophrenia. If shown to be promising, the findings from the proposed study would inform future intervention development efforts.
