Cognitive Recovery With Cannabis Abstinence Among High School-Aged Adolescents

This is a 5-year randomized, longitudinal trial of cannabis abstinence designed to determine
(1) if performance improves with abstinence beyond that observed with continued cannabis use,
and if so, (2) when during abstinence cognitive improvement occurs, and (3) whether
performance in abstinent individuals "returns" to performance levels observed in non-using
peers. We hypothesized that abstinent adolescent cannabis users would have more
neurocognitive improvement over four weeks compared to non-abstinent cannabis users, and
performance would continuously improve throughout four weeks of abstinence. We will recruit
210 adolescents with and without regular cannabis use. Eligible cannabis users will be
randomized to either a contingency management intervention which will incentivize 4 weeks of
cannabis abstinence (n = 70), or non-contingent monitoring with no abstinence requirement (n
= 70). All participants (including non-users; n = 70) will complete cognitive assessments,
toxicology testing, self-report questionnaires and semi-structured mood and substance use
interviews during the 4-week study as well as one 30-day follow-up visit. Abstinence will be
indexed by decreasing levels of cannabis metabolites in urine.

General Inclusion Criteria:

- Male and female adolescents from the Boston area who are between the ages of 13 and 19
(inclusive);

- Have a parent or legal guardian who is able and willing to provide written informed
consent for the active study phase (if under the age of 18);

- Competent and willing to provide written informed assent for the active study phase
(if under the age of 18);

- Competent and able to provide written informed consent (if age 18 or older)

- Able to communicate in English language

- Able to commit to 9 study visits in approximately 60 days

Cannabis-Using Group Inclusion Criteria:

- Use of cannabis at least once per week on most weeks

- Cannabis use reported within 7 days of both baseline visits

Non-Using Group Inclusion Criteria:

- Use of cannabis less than 5 times in lifetime

General Exclusion Criteria:

- 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.

Non-Using Group Exclusion Criteria:

- No cannabis use in the past year

- No cannabis use before age 16