Transcranial Direct Current Stimulation Provides No Additional Benefit to Improvements in Self-Reported Craving Following Mindfulness-Based Relapse Prevention

Mindfulness-Based Relapse Prevention (MBRP) and transcranial direct current stimulation (tDCS) have each demonstrated efficacy in improving outcomes in those with alcohol use disorder (AUD); however, a recent study that combined MBRP with tDCS found tDCS provided no additional benefit to MBRP for AUD. Differences in treatment adherence between active versus sham tDCS groups may have contributed to this result. The current study examined whether treatment adherence interacted with tDCS condition in predicting post-treatment mindfulness and craving. This study was a secondary data analysis from a randomized sham-controlled trial comparing MBRP paired with tDCS. Linear regression analyses were conducted examining the interaction between tDCS condition and two measures of treatment adherence (i.e., number of groups attended, number of tDCS administrations) on post-treatment mindfulness and craving. There was no effect of treatment adherence by tDCS condition in predicting mindfulness; however, the interaction between treatment adherence and tDCS condition significantly predicted post-treatment craving. There was a significant negative association between treatment adherence and post-treatment craving in the sham group, but there was no association in the active tDCS group. MBRP coupled with sham stimulation led to significant reductions in self-reported craving when patients attended more sessions and received a greater number of sham tDCS administrations, while no relationship was observed between treatment adherence and craving among those who received active tDCS. This result provides tentative evidence that, rather than improve the effects of MBRP on craving, this active tDCS protocol provides no additional benefit to MBRP in reducing craving.