Effects of transcranial direct current stimulation in individuals with schizophrenia: systematic review with meta-analysis

1Gisly Macedo de Sousa; 1Lucas Pereira dos Santos; 1Maria Carolina de Carvalho Sousa; 1Emerson Diógenes de Medeiros; 2Paulo Gregório Nascimento Silva; 1Paloma Cavalcante Bezerra de Medeiros

1 Universidade Federal do Piauí.     ;2 Universidade Federal da Paraíba

OBJECTIVE: To present the effects of TDCS (Transcranial Direct Current Stimulation) on positive and negative symptoms, neurocognition and social functioning in patients with schizophrenia, through a systematic review with meta-analysis.

METHODS: Based on Cochrane recommendations, a study protocol was established that included the databases Cochrane, Lilacs, Psycoinfo, Scielo, Scopus, Springer Link e Web of Science, with the descriptors: “transcranial direct current” AND "schizophrenia", ten eligibility criteria, procedural quality analysis and data analysis, and included articles published from 2012 to march 2019. The meta-analysis was performed using the Jasp 0.11.0.1. Ten studies were integrated into qualitative synthesis and into meta-analysis. Six meta-analyzes were performed.

RESULTS: The results show that TDCS is a tool for reducing the general and negative symptoms, and improving neurocognition. Null effects were found in positive symptoms, social functioning, neurocognition and social cognition.

CONCLUSIONS: This review points out existing gaps and highlights the need for studies with larger samples, as well as assessing the various models of electrode assembly and execution protocols so that it is possible identify a golden protocol for improving the symptoms presented and being able to prove its effectiveness in positive symptoms, neurocognitive, social cognition and social functioning.

KEYWORDS: Neuromodulation; Neurocognition; Symptoms; Schizophrenia

ACKNOWLEDGMENTS: None

FUNDING/FINANCIAL SUPPORT: None

DOI: https://doi.org/10.21801/ppcrj.2020.S1.43