Methamphetamine Dependence

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.

GEM is a two-phase study to evaluate the use of semaglutide (Wegovy) for the treatment of methamphetamine use disorder (MeUD). The first phase is a pilot study, which will be an open-label, single-arm pilot study of 25 participants. Participants will receive Wegovy over a 12-week treatment period, with a subsequent follow-up visit at week 20. This phase will evaluate the feasibility, acceptability, and preliminary efficacy of Wegovy for MeUD. The second phase will be a phase IIb randomized-controlled trial to determine the efficacy of Wegovy in treating MeUD. This trial will be similar to the pilot with randomization to Wegovy or placebo and blinding of group assignment. The trial will enroll 162 participants across two sites.

Methamphetamine use disorder (MUD) is becoming an increasing public health concern in Canada. While the evidence on the efficacy and safety of prescription psychostimulants for the treatment of MUD is promising, the knowledge on the maintenance therapy using stimulant agonist therapy is scarce and needs further investigation, especially in terms of long-term retention in treatment. The goal of this clinical trial is to evaluate the feasibility of a long-term (25 weeks) administration of high-dose stimulant agonist therapy, using Lisdexamfetamine (LDX-01) on top of treatment-as-usual (TAU), in a population of people with moderate to severe MUD, as measured by study retention, treatment retention, treatment adherence and satisfaction compared against a placebo group. Participants will be placed randomly into one of two groups: 1. TAU and high-dose LDX-01 2. TAU and placebo

The goal of this clinical trial is to learn if administering a high dose stimulant with Contingency Management reduces days of use in adults who use methamphetamine better than the usual treatment provided by the clinic. The main questions the trial aims to answer are: Is a high dose stimulant better than a placebo and usual treatment at helping reduce the number of days they use methamphetamine? Is a high dose stimulant with contingency management better than placebo and usual treatment at helping people reduce the number of days they use methamphetamine? Participants will be placed randomly into one of four groups: 1. Usual treatment and placebo 2. Usual treatment, placebo and contingency management 3. Usual treatment and high dose stimulant 4. Usual treatment, high dose stimulant and contingency management Participation includes the following: 1. Participants will receive medication or placebo weekly for 15 weeks. 2. Participants will attend the clinic for weekly treatment 3. Participants will attend the clinic once every 2 weeks for study visits. Each visit will take about an hour to complete. At these visits, participants will be asked to provide a urine sample and complete questionnaires.

During the first funding period (1st FP), the investigators developed a novel full Pavlovian-to-instrumental transfer (PIT) task that allows assessing both, general and specific PIT to investigate whether specific PIT differs between alcohol use disorder (AUD) and control subjects. Preliminary analyses of the full transfer task indicate that AUD participants exhibit a stronger specific PIT effect compared to controls. Based on these findings, the investigators want to compare specific and general PIT effects in patients with moderate to severe substance use disorders (alcohol, cannabis, methamphetamine, amphetamine and cocaine) to healthy controls on the behavioral and neural level (fMRI).

* Assess the antidepressant/anxiolytic effect of creatine in male and female methamphetamine users * Assess creatine's effect on methamphetamine use * Assess the safety of creatine in male methamphetamine users with depression