Addition of high dose Stimulant and engagement-focused Contingency management, alone and in combination, to treatment as usual for the management of MEthamphetamine use disorder (ASCME): a pan-Canadian multisite randomized controlled trial

Methamphetamine ("meth"; MA) use in Canada is on the rise. In the past decade, the number of deaths, hospitalizations, and emergency room visits due to MA and other stimulant use has increased across Canada. MA is highly addictive. Withdrawal symptoms include intense cravings, and long-term use can lead to psychosis (such as paranoia and hallucinations), and increased risk of HIV, Hepatitis C, and cardiovascular events (such as heart attack and stroke). Right now, there are no approved treatments for MA use disorder. There is some early evidence that using high-dose psychostimulants as substitution therapy can be effective against MA use disorder. Studies show that psychostimulants can reduce cravings and improve mental health, and high doses are safe. Contingency management, a type of treatment where a person is given an incentive for achieving certain behaviour change, has been successful in treating substance use disorders. Our stakeholder consultation showed that people with lived experience and clinicians are more receptive to using contingency management to support behavioural changes other than abstinence. Our study examines the effects of a high-dose stimulant lisdexamfetamine and contingency management, alone and in combination, on MA use compared with treatment as usual (which includes clinical management and behavioural therapies) in individuals with moderate to severe MA use disorder. For contingency management, we will incentivize attending clinic visits to receive treatment as usual. We will recruit a total of 440 participants in British Columbia, Manitoba, Ontario, Quebec, and New Brunswick. Our primary outcome will be self-reported MA use; we will also evaluate other key outcomes such as quality of life, craving, mental health, and adherence to treatment. This trial will help improve our understanding of substitution therapy and contingency management in MA use disorder, which will in turn improve care and support for individuals who use MA.