Overview

The primary aim of this project is to use a randomized single-blind sham-controlled study to investigate if high frequency repetitive transmagnetic stimulation (HF-rTMS) can modulate cue-induced craving in adult methamphetamine (METH) users. The investigators hypothesize that HF-rTMS directed at left dorsolateral prefrontal cortex (DLPFC) will result in a reduction in craving for METH compared to sham-controlled rTMS in adults with methamphetamine use disorder (MUD) as evidenced by validated measures of METH craving. Neurobiologically, the investigators anticipate rTMS mediated stimulation of the DLPFC could result in inhibition of cue-induced craving through potential disruption of involved circuitry. The current project proposes that participants who are recently abstinent from METH will be randomized into four experimental groups to provide two rTMS conditions (real versus sham) and two picture cues conditions (METH versus neutral). The experiment will have an induction phase where each subject will receive 10 daily treatments within 2 weeks. Just before each rTMS/sham session participants will be shown visual cues (METH or neutral). Participants will then undergo a maintenance phase for an additional month with assessments to evaluate craving and relapse. Urine samples for urine drug screening (UDS) will be collected at screening day and on days 1, 5 and 10. Just before each rTMS/sham session participants will be shown visual cues (METH and neutral). VAS craving scores will be assessed before and after picture presentation and after the rTMS/sham session. Before the first and 10th treatment session, participants were evaluated by the the Stimulant Craving Questionnaire (STCQ) and the Severity of Dependence Scale (SDS) questionnaires. Participants will then undergo a maintenance phase for an additional month. During the first week of maintenance, three rTMS/sham sessions will be administered. During each of the following 3 weeks, one rTMS/sham session will be given per week. As with the induction phase, urine samples will be collected for screening and STCQ and the SDS questionnaires will be completed at each maintenance session. To evaluate the long-term effects of the rTMS treatment, the investigators plan on contacting participants 6 months after treatment termination for all subjects who completed the 10 treatment sessions. During that phone conversation, craving and relapse will again be assessed.

Eligibility

Inclusion Criteria:

• Subjects must use at least 0.5 g per day at least 5 days per week and have a minimum 12-month history of METH abuse.
• Subjects must meet DSM V diagnosis for methamphetamine use disorder.
• Subjects must have a minimum 4-week period of detoxification and a desire to stop using methamphetamine.

Exclusion Criteria:

• Present or past history of neurological disorder
• The present history of a DSM IV Axis I or DSM V primary psychiatric disease (apart from MUD and depressive symptoms defined as a Hamilton Depression Scale Score < 7 ("normal"))
• Scores on the Hamilton Depression Scale > 8, possibly indicating clinical depression
• No current abuse of drugs other than methamphetamine (except nicotine). Urine-screening tests for psychoactive drugs will be performed to corroborate the lack of drug use.
• Individuals meeting criteria for cannabis use disorder or alcohol use disorder
• Medical illness that can affect brain function
• Past or present history of cardiovascular disease or high blood pressure
• Any history of epilepsy or a known history of seizure disorder
• A history of metal in the head or chest area (except dental fillings or braces)
• Current consumption of psychiatric medication
• Any other medical, neurological or neurosurgical condition that would preclude the administration of repetitive transmagnetic stimulation