Targeting Craving in Methamphetamine Relapse Prevention with Transcranial Direct Current Stimulation: A Hospital-Based Sham-Controlled Pilot Study

Abstract

Background: Methamphetamine use disorder (MUD) is a chronic and relapsing condition that severely impacts an individual's physical, emotional, and social well-being. Despite numerous interventions, including pharmacological treatments and psychological therapies, sustained abstinence remains a significant challenge. The complexity of addiction, particularly the role of craving and impulsivity, underscores the need for innovative therapeutic strategies. Transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique, has gained attention for its potential to modulate neural circuits involved in craving and impulsivity, particularly within the prefrontal cortex, which is implicated in the regulation of addictive behaviors. Objectives: The aim of this pilot study is to evaluate the impact of tDCS on craving reduction, impulsivity, and emotional regulation in individuals with MUD, and to assess its potential role in relapse prevention. Methods: This study included 20 participants diagnosed with MUD, recruited during hospitalization in 2024. Participants were randomly assigned to either the real tDCS group or the sham control group. The tDCS intervention consisted of 10 daily sessions using 2 mA current, applied to the right and left dorsolateral prefrontal cortex (DLPFC). Assessments of craving, impulsivity, and emotional affect were conducted at four time points: Pre-test (T0), post-session 5 (T1), post-session 10 (T2), and a two-week follow-up (T3) using the Desire for Drug Questionnaire (DDQ), Barratt Impulsivity Scale (BIS), and positive and negative affect schedule (PANAS). Results: Craving scores demonstrated a marked reduction over time in both groups, with the real tDCS group exhibiting a more substantial decrease from pre-test (33.4 ± 18.73) to follow-up (13.0 ± 16.22). Impulsivity showed minimal group differences, with no significant time × group interactions. In terms of affect, the real tDCS group experienced a moderate increase in positive affect (from 27.3 ± 2.24 to 32.0 ± 2.24) and a notable decrease in negative affect (from 28.6 ± 3.02 to 20.1 ± 2.24). While statistical analysis revealed significant time effects for some measures, group effects and time × group interactions were generally non-significant. Conclusions: This study suggests that tDCS may have potential in reducing craving and improving emotional regulation in individuals with MUD; however, the effects were modest and not consistently sustained over time. The findings should be interpreted with caution due to the small sample size, short follow-up duration, and the hospital-based nature of the sample, which may limit generalizability to broader community settings. Nevertheless, these preliminary results support the feasibility of tDCS as an adjunctive intervention, and larger randomized trials with longer follow-up are warranted to confirm its clinical effectiveness and long-term impact on relapse prevention.