A sham-controlled clinical trial to examine the effect of bilateral tDCS on craving, TNF-α and IL-6 expression levels, and impulsivity of males with opioid use disorder.

BACKGROUND: Opioid use disorder (OUD) is one of the problems and concerns of all countries in the world. On the other hand, transcranial direct current stimulation (tDCS) has been used as a new therapeutic intervention in various psychiatric disorders. OBJECTIVE: This study aimed to investigate the effect of bilateral tDCS on the expression levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), craving and impulsive behaviors of male patients with OUD. METHODS: This is a double-blind sham-controlled clinical trial. Participants were 31 male patients with OUD divided into three groups of left anode/right cathode tDCS, right anode/left cathode tDCS, and sham tDCS. They received active tDCS (2 mA, 20 min), applied over their dorsolateral prefrontal cortex (DLPFC) for 10 consecutive days. Expression levels of IL-6 and TNF-α cytokines were measured using ELISA method, and the Desires for Drug Questionnaire and the Barratt Impulsiveness Scale version 11 were used to assess the craving and impulsivity of subjects, respectively. RESULTS: Both active and sham tDCS could significantly reduce drug craving in subjects (p < 0.05). Active tDCS over the right/left DLPFC significantly reduced impulsivity and its dimensions (overall, attentional, motor, and nonplanning) compared to the sham tDCS (p < 0.05). It could also reduce the expression levels of IL-6 and TNF-α, but the difference was not statistically significant. CONCLUSIONS: The active tDCS over the right/left DLPFC, as a noninvasive and complementary treatment, can be used along with other common methods for the treatment of patients with OUD. It can improve their cognitive functions by reducing impulsivity.