Effect of Medical Marijuana on Neurocognition and Escalation of Use

Effect of Medical Marijuana on Neurocognition and Escalation of Use

This study will use a randomized controlled design to test whether patients who use medical marijuana, compared to a waitlist control group, experience a change in health outcomes (relief of symptoms, or adverse health outcomes such as new-onset symptoms of cannabis use disorders, neurocognitive impairments) or brain-based changes.

This trial is a randomized, longitudinal study of medical marijuana (MM) that will: (1) characterize the impact of MM on indices of addiction, such as CUD, escalation of use, tolerance, and withdrawal among those who stop using, (2) assess, via dosing diaries, the effect of MM use patterns on use of other medications, and perception of underlying disease symptomatology, (3) characterize the impact of MM on neurocognitive performance, including executive function, memory, attention, and decision-making and (4) examine evidence for impact of MM on brain structure and function. This study will enroll 200 adults with no prior history of CUD or heavy marijuana use, who express interest in using MM to treat pain, insomnia, anxiety, and/or depression. Participants will be randomly assigned to either an active MM arm (n = 100), or to a waitlist control arm (WLC) (n = 100). Participants will be assessed at baseline, regularly for 3 months, and at a 6-month and 12-month follow-up for MM use behaviors, development of CUD, perception of disease symptomatology, and neurocognitive performance. Urine collected at each visit will be assessed with quantitative assays. MRI scans will be collected to longitudinally investigate possible brain changes associated with MM use.

Inclusion Criteria:

1. Men and women aged 18-65 years, inclusive;
2. Competent and willing to provide written informed consent;
3. Desire to use medical marijuana for self-reported pain, sleep, or affective (mood and/or anxiety including PTSD) symptoms.
4. Not in possession of a medical marijuana card, but expressing intent to get one.
5. Able to communicate in English language.

Exclusion Criteria:

1. Current daily marijuana use (prior to enrollment)
2. Current substance use disorders (e.g. cocaine, opiate, stimulant). Light to moderate alcohol use is permitted (defined as 16 or less on the AUDIT), and nicotine dependence is permitted because of the high co-use of nicotine and marijuana. Participants cannot meet current SCID criteria for a use disorder on any illicit substance other than nicotine.
3. Pregnant (verified by a urine test).
4. In the opinion of the investigator, not able to safely participate in this study because of any medical or psychological issues (e.g. psychosis) that might compromise their safety.