Imaging the Effects of Intermittent Thetaburst Stimulation on Cannabis Self-Administration in Heavy Cannabis Users
Duke University
Summary
The growing legalization of cannabis across the U.S. is associated with increases in cannabis use, and accordingly, an increase in the number of individuals with cannabis use problems, including cannabis use disorder (CUD). While there are several medications being investigated as treatment options for CUD, none have been FDA-approved, and there is limited efficacy of traditional behavioral therapy approaches for this population. Consequently, there is a pressing need for the development of new treatments, including approaches that specifically target the brain areas associated with problematic cannabis use behaviors. Elevated attention to drug cues is one of the primary causes of relapse in heavy cannabis users. Preliminary data suggests that repetitive transcranial magnetic stimulation (rTMS), a non-invasive form of brain stimulation, may be a novel brain-based tool to decrease heightened attention to drug cues in people with CUD. Building on prior data, the primary goal of this study is to evaluate the feasibility and effectiveness of TMS as a tool to decrease attention to drug cues and reduce cannabis use. In this study, fifty (50) treatment-seeking, near-daily cannabis users will be recruited to receive either active or sham (placebo) repetitive TMS (rTMS). Participants will complete a total of 25 treatment sessions, delivered as five sessions per day across five days, with sessions flexibly scheduled over a two-week period. Measures of cannabis use and brain activity will be collected before and after treatment using real-time self-report assessments and functional magnetic resonance imaging (fMRI), respectively. Specifically, cannabis use will be assessed in participants' everyday environments using brief text-message surveys during a two-week baseline period, the two-week treatment period, and a four-week follow-up period. The study aims to determine whether active rTMS reduces brain activity in response to cannabis cues, decreases automatic attention to cannabis cues, and leads to meaningful reductions in cannabis use compared to sham treatment.
Description
The expanding legalization of cannabis across the U.S. is associated with increases in cannabis use and, accordingly, an increase in the number of individuals with cannabis use disorder (CUD). One key predictor of relapse is elevated attentional bias to drug cues, coupled with attenuated cognitive control in the presence of those cues. Attentional bias to drug cues is associated with increased activity in the Salience Network (SN), including the anterior cingulate cortex and bilateral anterior insula, as well as reduced activity in the dorsolateral prefrontal cortex (DLPFC) and broader cogniti…