Transcranial direct current stimulation of the prefrontal cortex reduces cue-reactivity in alcohol-dependent patients

Alcohol craving has been shown to be an important factor for relapses in alcohol-dependent patients. Furthermore, brain activity in reward-related areas in response to alcohol-related cues is positively related to the amount of post-relapse alcohol consumption. On the other hand, it has been shown that cue-exposure based extinction training (CET) leads to larger decrease of striatal and left dorsolateral prefrontal cortex (dLPFC) cue-induced activation compared to standard clinical day-care treatment, but the effect sizes are relatively small. The question of this study was, whether it is possible to change cue-reactivity and subjective craving by applying bilateral prefrontal transcranial direct current stimulation (tDCS). We stimulated 30 detoxified alcohol-dependent patients (50 % with a sham and 50 % with left cathodal/right anodal stimulation) and presented emotional as well as alcohol-related pictures. We measured the emotional startle modulation and found significantly increased startle amplitudes in the verum stimulation condition for alcohol-related cues, indicating a more negative processing of this cues in alcohol-dependent patients after verum tDCS stimulation. Additionally we found tendencies for stronger reduction in subjective craving in verum-stimulated patients. Therefore our study underscores the positive value of DCS in reducing craving and might help to improve the understanding and therapy of alcohol dependence.