This study is to explore if repetitive transcrinal magnetic stimulation (rTMS) with different stimulation schedules will be equally effective in reducing carving, frequency of cannabis use, and the severity of cannabis use disorder in participants suffering from cannabis use disorder (CUD).

The investigators assume the hypotheses as:

1. Multiple rTMS sessions can reduce craving for cannabis, severity of CUD, frequency and amount of cannabis use.
2. Different rTMS treatment schedules have differences in reducing the craving for cannabis and severity of CUD, and prolonging relapse of cannabis use.

Inclusion Criteria:

• Able to read and communicate in English and/or Chinese SToP-C-rTMS x CUD
• Able to give informed consent
• Using cannabis or marijuana as the primary psychoactive substance of abuse
• Diagnosed with Cannabis Use Disorder according to the Diagnostic and Statistical Manual of Mental Disorders 5th Edition (DSM-5) by the Structured Clinical Interview for DSM-5 Disorders (SCID-5)

Exclusion Criteria:

• Age <18 years old
• Unable to read English or Chinese
• Unable to give informed consent
• Had been diagnosed with the following disorders, including neurodevelopmental disorders, DSM-5 defined substance use disorder greater than moderate in severity, and neurocognitive disorders
• Contra-indicated to have rTMS, including subjects with electronic and/or magnetic implants (e.g. pacemaker, implantable cardioverter defibrillator [ICD], cerebral shunts, cochlear implant, etc.), with metallic or mechanic fragments (e.g., screws, plates, stents, clips, etc.), pregnant, with any known or history of neurological conditions including cerebral vascular accidents, epilepsy, brain tumor or space occupying lesion, poorly controlled or unstable diabetes mellitus, and receiving unstable dose(s) of antipsychotics, antidepressants, benzodiazepines and/or anticonvulsants in the past 6 months