Effect of Adjunctive High-Definition Transcranial Direct Current Stimulation (HD-tDCS) to Oral Naltrexone on Craving, Brain Glutamate-Glutamine (Glx) at Left Dorsolateral Prefrontal Cortex (DLPFC) in Alcohol Use Disorder: A Randomized Sham-Controlled HD-tDCS-fMRS Study.

BACKGROUND

Alcohol use disorder (AUD) is a chronic relapsing condition requiring long-term pharmacotherapy. Because of their variable efficacy and poor adherence, newer neuromodulation approaches are being examined. Our study aimed to investigate the effect of adjunctive high-definition transcranial direct current stimulation (HD-tDCS) on craving, brain glutamate-glutamine (Glx) at the left dorsolateral prefrontal cortex (DLPFC) in AUD.

METHODS

A total of 50 individuals with AUD, randomized into 25 each to active and sham HD-tDCS groups were enrolled on the study. After detoxification, HD-tDCS was administered twice daily over 5 days for a total of 10 sessions. Each participant was started on oral naltrexone 50 mg/day. Alcohol craving questionnaire-NOW (ACQ-NOW), obsessive compulsive drinking scale (OCDS), and brain Glx were measured at baseline and end of 10 sessions of high-definition transcranial direct current stimulation.

RESULTS

The active HD-tDCS group showed significantly lower brain Glx at the left DLPFC at the end of 10 sessions from baseline compared with the sham HD-tDCS group. Craving did not show any significant between-group × time effects.

CONCLUSIONS

Our study showed that the HD-tDCS could significantly change brain Glx at the left DLPFC in AUD. Change in craving did not correlate with change in Glx. Future studies should include a larger sample size, multivoxel assessment and a greater number of HD-tDCS sessions.