The Effects of Theta Burst Stimulation on the Brain Response to Drug and Alcohol Cues

Overview

High relapse rates among substance dependent individuals are likely due to a combination of factors that involve limbic circuits in the brain involved in craving, including vulnerability to salient cues. Emerging data suggests that non-invasive, targeted brain stimulation may be able to modulate activity in these circuits and decrease craving. The primary goal of this pilot study is to determine the extent to which a single session of continuous theta burst stimulation to the medial prefrontal cortex can attenuate limbic circuitry involved in craving among cocaine users and alcohol users. This will be tested through a double-blind,sham-controlled brain stimulation and brain imaging study in a cohort of polysubstance abusers and alcohol users.

This parent protocol contains two components - one of which is targeting cocaine users, the other of which is targeting heavy alcohol users (who will also serve as an appropriate control group for the cocaine users - who typically have comorbid alcohol use disorders). All participants will receive one session of real and one session of sham (randomized) continuous theta burst stimulation (TBS).TBS is a form of non-invasive transcranial magnetic stimulation (TMS).Continuous TBS is designed to lower cortical excitability, and requires a shorter stimulation period than typical low frequency TMS. The investigators will test the hypotheses that stimulation over the medial prefrontal cortex will attenuate activity in the medial prefrontal cortex (Aim 1), using single pulse TMS in the magnetic resonance imaging scanner. Through this innovative technique it is possible to apply a single pulse of TMS to the medial prefrontal cortex and model the hemodynamic response at the stimulation site as well as monosynaptic target regions, including the striatum. The investigators will also investigate the effect of TBS on neural response to drug cues (Aim 2). The results of these aims will be further correlated with self-reported assessments of craving throughout each experimental visit. These data will be preliminary data for a subsequent R01 focused on the sustained effects of multiple sessions of TBS and their efficacy in lowering craving for extended periods of time in treatment-seekers.