Noninvasive brain stimulation in alcohol craving: A systematic review and meta-analysis.

BACKGROUND

Alcohol dependence (AD) is characterized by a set of physical and behavioral symptoms, which may include withdrawal, tolerance and craving. Recently, noninvasive brain stimulation (NIBS) methods, namely transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS), have been investigated as possible new therapeutic approaches for adjusting the pathological neuroplasticity involved in alcohol dependence. Therefore, we conducted a systematic review and meta-analysis on the therapeutic uses of tDCS and rTMS in AD patients.

METHODS

A systematic search was performed on Scopus, Web of Science, PubMed, Cochrane library and ProQuest. Search terms presented the diagnoses of interest (alcohol dependence, alcohol craving, alcohol use disorders and hazardous drinkers) and the intervention of interest (NIBS, TMS, rTMS, TBS, tDCS, tACS and transcranial). Original articles reporting the use of tDCS or rTMS to treat AD were screened and studied by two researchers independently based on PRISMA guidelines. Next, in the meta-analysis step, random-effects model was utilized to measure the pooled effect size.

RESULTS

We found 34 eligible studies including 11 tDCS trials and 23 rTMS trials. Three of these studies were case-reports, four were open label trials and the remaining 27 were controlled trials which assessed tDCS/rTMS effects on the three cognitive, behavioral and biological dimensions in AD. The pooled standardized mean differences for the effects of tDCS and rTMS on alcohol cravings were - 0.13 [-0.34, 0.08] and - 0.43 [-1.02, 0.17], respectively.

CONCLUSION

There is no evidence for a positive effect of tDCS/rTMS on various dimensions of AD. We need more randomized, double blind, sham controlled trials with enough follow-up periods to evaluate the efficacy of tDCS/rTMS for alcohol dependence treatment.