Modulation of Drug Craving in Crystalline-Heroin Users by Transcranial Direct Current Stimulation of Dorsolateral Prefrontal Cortex

Drug craving, the main cause of relapse and a major motivator for drug use, is a challenging obstacle in substance use treatment. Transcranial direct current stimulation (tDCS), a non-invasive neuromodulatory technique, has shown promising outcomes in treating different neuropsychiatric disorders such as drug addiction, more specifically on drug craving. The aim in the current study was to examine the effects of applying tDCS on dorsolateral prefrontal cortex (DLPFC) in reducing drug cravings in former crystalline-heroin users enrolled in methadone maintenance (MMT) programs. The present study was a semi-experimental, crossover study with pre/post-test, and a control group. 40 right-handed men were selected from former crystalline-heroin users enrolled in MMT programs in Tehran, Iran. They were then divided into two matched groups based on age, education, and age of onset crystalline-heroin abuse. Desire for Drug Questionnaire (DDQ) was administered two times to all of the subjects, before first brain stimulation, and at the end of the last session. Experimental group received TDCS on DLPFC, and sham stimulation was applied on control subjects. The data were analyzed by analysis of covariance (ANCOVA) method using SPSS software. The study results indicated anodal tDCS over right and cathodal TDCS over left DLPFC, and in parallel with sham, significantly decreased drug cravings among former crystalline-heroin users (P < 0.050). This study showed that applying TDCS on DLPFC of former crystalline-heroin users reduces drug craving. The findings of this study expanded the results of previous studies on effects of this neuromodulatory technique for drug craving reduction in other drug type settings.