A protocol for high-dose lisdexamfetamine and contingency management, alone or in combination, for the treatment of methamphetamine use disorder: The ASCME study

Background

The prevalence of methamphetamine use disorder is increasing in North America. Well-evidenced treatment options are currently limited to behavioural interventions, with contingency management (CM) regarded as the most effective approach. Psychostimulants have been identified as a potentially promising treatment for methamphetamine use disorder, particularly at higher doses. This study was designed to examine the effectiveness of a high-dose daily psychostimulant (lisdexamfetamine; LDX) and CM, both alone and in combination, in addition to treatment-as-usual (TAU) for the treatment of moderate-to-severe methamphetamine use disorder.

Methods

The ASCME study is a multicentre, four-arm, blinded, randomized, placebo-controlled clinical trial examining the effectiveness of adding LDX (250 mg) and CM, alone or in combination, to TAU in reducing days of methamphetamine use among adults with moderate-to-severe methamphetamine use disorder. A total of 440 participants will be randomized across 5 sites to 12 weeks of 1) LDX + TAU + CM; 2) LDX + TAU; 3) placebo + CM + TAU; and 4) placebo + TAU. The primary outcome is reduction in days of self-reported methamphetamine use, with secondary outcomes including treatment retention, sustained abstinence, safety, medication adherence, satisfaction, and quality of life.

Conclusion

This study will be the largest study to date examining the effectiveness of a prescribed psychostimulant in the treatment of methamphetamine use disorder, and the first of its kind to employ a four-arm approach to evaluate the added benefit of its combination with CM on psychostimulant treatment. The development of pharmacologic treatments for methamphetamine use disorder remains an urgent research goal.