Efficacy of transcranial direct current stimulation in ameliorating negative symptoms and cognitive impairments in schizophrenia: A systematic review and meta-analysis

Lingfang Yu; Xinyu Fang; Yan Chen; Yewei Wang; Dandan Wang; Chen Zhang

doi:10.1016/j.schres.2020.10.006

Efficacy of transcranial direct current stimulation in ameliorating negative symptoms and cognitive impairments in schizophrenia: A systematic review and meta-analysis

Schizophr Res. 2020 Oct:224:2-10. doi: 10.1016/j.schres.2020.10.006. Epub 2020 Oct 28.

Authors

Lingfang Yu¹, Xinyu Fang², Yan Chen¹, Yewei Wang¹, Dandan Wang¹, Chen Zhang³

Affiliations

¹ Schizophrenia Program, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Biochemical Pharmacology Laboratory, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China.
² The Affiliated Brain Hospital of Nanjing Medical University, Nanjing 210029, China.
³ Schizophrenia Program, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Biochemical Pharmacology Laboratory, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China. Electronic address: zhangchen645@gmail.com.

PMID: 33129639
DOI: 10.1016/j.schres.2020.10.006

Abstract

Aims: Negative symptoms and cognitive impairments in schizophrenia patients are associated with the patients' functional outcomes and quality of life. However, pharmacotherapy has little effect on such symptoms. This study aimed to systematically evaluate the efficacy of transcranial direct current stimulation (tDCS) in ameliorating negative symptoms and cognitive impairments in schizophrenia patients.

Methods: A literature search was performed in the PubMed, Embase, PsycINFO and Cochrane Library databases through March 23, 2020. Studies were included if they met all the following criteria: (1) subjects were exclusively patients with schizophrenia, schizoaffective disorder or psychosis, (2) active tDCS and shame stimulation were conducted in two parallel groups, (3) sufficient data were present, and (4) the study design was based on a randomized controlled trial. Two authors conducted the search strategy, publication assessment and data extraction independently, and a third person was consulted when any disagreement emerged.

Results: A total of 14 studies were included (12 studies included negative symptoms and 7 studies included cognitive impairments). The overall meta-analysis showed no significant difference between active and sham tDCS in ameliorating negative symptoms in schizophrenia patients (SMD: -0.14, 95% CI: -0.33- 0.05). Subgroup analysis including studies with a high stimulation frequency, twice daily, revealed a significant difference in therapeutic effects between active tDCS and sham stimulation (SMD: -0.31, 95% CI: -0.58 to -0.05). With respect to cognitive impairments, there was a trend indicating that active tDCS might improve cognitive impairment (SMD: -0.21, 95% CI: -0.46- 0.04), but the overall meta-analysis failed to obtain statistically significant results.

Conclusion: Our meta-analysis indicates that tDCS is a potential strategy for improving negative symptoms, but the therapeutic benefit for negative symptoms requires a high stimulation frequency (twice a day).

Keywords: Cognitive impairments; Negative symptoms; Schizophrenia; Transcranial direct current stimulation.

Publication types

Meta-Analysis
Research Support, Non-U.S. Gov't
Review
Systematic Review

MeSH terms

Cognitive Dysfunction* / etiology
Cognitive Dysfunction* / therapy
Humans
Quality of Life
Randomized Controlled Trials as Topic
Schizophrenia* / complications
Schizophrenia* / therapy
Transcranial Direct Current Stimulation*