A Systematic Review of the Effect of Short Term Transcranial Direct Current Stimulation Therapy in Methamphetamine Use Disorder

Background: Methamphetamine use disorder (MUD) has become more and more common. Some studies have shown that Transcranial Direct Current stimulation (tDCS) may reduce craving when stimulating the dorsal lateral prefrontal cortex. Objectives: The aim of this systematic review was to evaluate the effect of transcranial direct current stimulation (tDCS) on MUD. Databases were searched through May 2022. Randomized Controlled Trials (RCT) and pre-post studies investigating the efficacy of tDCS in MUD were included. The Cochrane Manual of Systematic Evaluation 6.3 bias risk assessment tool was used to assess the risk of bias. For each article, where possible, we extracted the population(s), standardized mean differences (SMD), standard deviations, and other study metrics (design, year, randomization, and details) on efficacy and tolerability outcomes. We assessed each article's quality via the GRADE assessment protocol. Results: Six studies involving 220 patients were included. All six studies included reported continuous data on craving. Results from craving favored active tDCS over sham tDCS at the end of treatment (SMD −0.58, 95% CI −0.85 to −0.30; studies = 6, participants = 220; I2 = 60%). Tolerability data showed that tDCS does not cause more tingling or itching sensation compared to sham tDCS. Conclusions: Further trials with larger sample sizes and longer durations are needed to determine whether tDCS is a valuable tool in treating MUD.