Repetitive Transcranial Magnetic Stimulation (rTMS) Administration to Heavy Cannabis Users

TITLE
Repetitive Transcranial Magnetic Stimulation (rTMS) Administration to Heavy Cannabis Users

AUTHORS
Sahlem GL; Baker NL; George MS; Malcolm RJ; McRae-Clark AL.

SOURCE
American Journal of Drug & Alcohol Abuse. 44(1):47-55, 2018.

ABSTRACT
Cannabis use disorder (CUD) is a common condition with few treatments. Several studies in other substance use disorders have found that applying repetitive transcranial magnetic stimulation (rTMS) to the dorsolateral prefrontal cortex (DLPFC) decreases cue-elicited craving and possibly decreases use. To date, there have been no studies attempting to use rTMS in CUD.

OBJECTIVES
This study was conducted to determine if rTMS could be feasibly delivered to a group of non-treatment seeking CUD participants. Secondarily, the study aimed to estimate the effect of rTMS on craving.

METHODS
In a double-blind, sham-controlled, crossover design, a single session of active or sham rTMS (Left DLPFC, 10 Hz, 110% rMT, 4000 pulses) was delivered during a validated cannabis cue paradigm. Participants crossed over to complete the other condition one week later. The feasibility and tolerability were measured by the rate of retention, and the percentage of participants able to tolerate full dose rTMS, respectively. Craving was measured using the Marijuana Craving Questionnaire (MCQ).

RESULTS
Eighteen non-treatment seeking CUD participants were recruited from the community; 16 (three women) completed the trial (89% retained for the three study visits). All of the treatment completers tolerated rTMS at full dose without adverse effects. There was not a significant reduction in the total MCQ when participants received active rTMS as compared to sham rTMS.

CONCLUSION
rTMS can be safely and feasibly delivered to CUD participants, and treatment is well tolerated. A single session of rTMS applied to the DLPFC may not reduce cue-elicited craving in heavy cannabis users.