T188. THE CLINICAL SCIENCE OF TRANSCRANIAL DIRECT CURRENT STIMULATION STUDIES IN SCHIZOPHRENIA: SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract Background Transcranial direct current stimulation interventions have produced findings that inform clinical neuroscience, and may have potential as a treatment for the cognitive symptoms of schizophrenia-spectrum illnesses. The first recorded study of tDCS in this population was in 1994 and every year since then has seen growth in the number of studies conducted, with 15+ studies each year since 2013. This project is a meta-analysis of studies using transcranial direct current stimulation in people with schizophrenia-spectrum illnesses and any domain of cognition. Methods Search terms sought out articles in populations with schizophrenia, schizoaffective, schizotypal, schizoid, unspecified psychosis, and thought disorder illnesses. Within these populations, non-invasive electrical stimulation terms included transcranial direct current stimulation, tDCS, and transcranial electrical stimulation. Within those studies, cognitive terms included working memory, memory, cognitive control, executive function, attention, recall, recognition, perception, learning, cognition, inhibition, and executive control. PRISMA guidelines were followed. Results 177 Articles were located through a literature search using the PubMed database. 39 studies were screened out by title, 102 studies were screened out by abstract, 7 studies were screened out by text. Finally, 29 studies were subjected to meta-analysis. Discussion While the research on transcranial direct current stimulation continues to develop, the current study highlights methodological trends like studies with stimulation concurrent to task and those using training approaches. Overall effects are summarized by defining study characteristics and cognitive domains, where appropriate.