Experimental Manipulation of the Emotional Salience of Cannabis Use-Related Information in Regular Cannabis Users

Summary

The goal of this study is to test a causal neural mechanism of cannabis use-related problem recognition in individuals with severe cannabis use disorder using a non-invasive form of neuromodulation called transcranial magnetic stimulation (TMS). The main question it aims to answer is: -Does manipulating neural activity in the medial orbitofrontal cortex of the brain affect cannabis use-related problem recognition? Researchers will compare three forms of theta burst stimulation (TBS; sham, intermittent, and continuous) in each participant to see if manipulations in neural activity lead to changes in cannabis use-related problem recognition. Participants will complete a screening interview about their mental health and substance use history and complete four in-person laboratory sessions, which involve questionnaires, four brief magnetic resonance imaging (MRI) scans, three TBS sessions, and three electroencephalogram (EEG) sessions. Participants will also be asked to provide urine samples and take saliva and/or breathalyzer tests at some of the lab visits.

Eligibility

Age range

18–50 years

Sex

All

Healthy volunteers

No

Interventions

• Device
  TMS - Sham

  For sham TMS, participants will receive a placebo version of either cTBS or iTBS (in a counterbalanced order). To do this, we will use the "placebo" side of the TMS coil, which produces the same sound volume and sequence as active TMS but does not induce neuromodulatory effects due to using the opposite side of the TMS coil as the "active" side TMS coil. To simulate somatosensory effects of active TMS, sham TMS also use superficial stimulation with the same pulse sequence via a small electrode placed on the target region underneath the coil.

• Device
  TMS - Active iTBS

  Trains consisting of bursts of three stimuli at 50 Hz repeated at 5 Hz frequency delivered at 110% of measured individual motor threshold in 20 x 2-second trains with 8-second intertrain intervals (192 seconds total)

• Device
  TMS - Active cTBS

  Trains consisting of bursts of three stimuli at 50 Hz repeated at 5 Hz frequency delivered at 110% of measured individual motor threshold in 1 x 40-second train (40 seconds total)

Location