Project Summary / Abstract: Cannabis use disorder (CUD) is a common condition with few validated treatments and, to date, no FDA- approved medications. Subsequently, providers have few options to offer treatment seekers. An expanding literature base suggests that a single treatment of excitatory repetitive Transcranial Magnetic stimulation (rTMS) applied to the dorsolateral pre-frontal cortex (DLPFC) may temporarily reduce drug cue induced craving across substance use disorders. Two recent clinical trials suggest that delivering a course of multiple rTMS treatments holds promise as a potential treatment for tobacco and cocaine use disorders. Consistent with the findings in addictions, in Major Depressive Disorder a single treatment of rTMS has little if any mood effect; however repeated treatments result in clinically meaningful improvement and remission from depression in a substantial number of depressed patients. The candidate and mentorship team recently completed a laboratory-based trial demonstrating that a single treatment of rTMS is safe, tolerable, and feasible in non-treatment seeking cannabis use disordered participants. Additionally, rTMS reduced cannabis cue-induced craving. Given these promising preliminary findings, it is possible that a full course of rTMS would have a larger effect on craving and an effect on cannabis use. In this application for a career development award, the candidate proposes to determine if a course of rTMS treatments applied to the DLPFC can result in reduced cannabis cue-induced craving (Aim1) and cue reactivity in reward structures during an fMRI paradigm (Aim2) in treatment seeking cannabis use disordered individuals. Additionally, he will determine if a course of rTMS reduces cannabis use (Exploratory Aim). Development of a novel, effective treatment for CUD would have the potential of helping the estimated one million cannabis using Americans that seek treatment each year. Of note, rTMS is a treatment with few side effects, and it may focally target CUD's pathophysiology.