Clinical Trial of High Dose Lisdexamfetamine and Contingency Management in MA Users

Inclusion Criteria:

• Participant must meet all the following criteria:

1. Between 18 and 55 years of age;

2. Diagnosed with a moderate to severe methamphetamine (MA) use disorder asdefined by the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th edition) criteria;

3. Active MA use at screening measured via self-reported MA use ≥14 days in thepast 28 days AND verified by urine drug metabolite testing;

4. Interested in reducing/stopping MA use;

5. If female:

6. Be of non-childbearing potential, defined as (i) postmenopausal (12 monthsof spontaneous amenorrhea and ≥ 45 years of age); or (ii) documentedsurgically sterilized (i.e., tubal ligation, hysterectomy, or bilateraloophorectomy); or

7. Be of childbearing potential, have a negative pregnancy test at screening,and agree to use an acceptable method of birth control throughout thestudy;

8. Willing to be randomized to one of the 4 study arms and followed for theduration of the trial;

9. Able to provide informed consent;

10. Willing to comply with study procedures;

11. Able to communicate in English or French.

Exclusion Criteria:

• 1. Symptomatic or advanced cardiovascular disease (e.g., advanced arteriosclerosis),moderate hypertension; current hyperthyroidism confirmed via blood test; knownhypersensitivity or idiosyncrasy to the sympathomimetic amines or glaucoma or anydisabling, severe, OR unstable medical condition that, in the opinion of the studyphysician, precludes safe participation or the ability to provide fully informedconsent; 2. Any severe or unstable co-morbid substance use disorder that, in theopinion of the study physician, precludes safe participation in the study; 3.Participants with Opioid Use Disorder (OUD) who have been on Opioid Agonist Therapy (OAT) for < 12 weeks, and not yet at stabilization dose, or at stabilization dose < 4 weeks; 4. Current or history of any serious psychiatric disorder (e.g., bipolardisorder, pre-existing psychosis, schizophrenia) that, in the opinion of the studyphysician, precludes safe participation in the study; 5. History of a severe adverseevent, hypersensitivity or known allergic reaction to LDX or other amphetamine drugsOR hypersensitivity to the sympathomimetic amines; 6. Pregnant, nursing, or planningto become pregnant during the study period; 7. Planned extended absence during studyperiod (e.g., pending legal action, surgery, incarceration, inpatient residentialprogram) in the opinion of the study physician that might prevent completion of thestudy; 8. Use of an investigational drug for stimulant use disorder during the 30days prior to screening, confirmed via self-report OR pharmacy records; 9. Currentlyreceiving contingency management for the treatment of stimulant use disorder in the 4 weeks prior to screening, confirmed via self-report OR site records; 10. Use ofprescribed amphetamine-type medication OR medication for the treatment of stimulantuse disorder (e.g., methylphenidate, modafinil, bupropion) in the 4 weeks prior toscreening; 11. Current or anticipated need for treatment with any medication thatmay interact with LDX (e.g., proton pump inhibitors, monoamine oxidase inhibitors [MAOIs]) used currently or within the past 14 days AND that would preclude studyparticipant at the discretion of the study physician