Cognitive Recovery With Cannabis Abstinence Among High School-Aged Adolescents

This study will use a randomized controlled design to test whether 30 days of cannabis abstinence, compared to 30 days of monitoring, is associated with improvements in cognitive functioning. Non-using controls will also be enrolled to determine the clinical significance of any cognitive improvements with abstinence.

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.

Cannabis users are randomized either to 30 days of cannabis abstinence or 30 days of monitoring with no abstinence requirement. Non-users are not randomized.

Cannabis users randomized to this condition will be enrolled in a contingency management intervention for 30 days of cannabis abstinence.

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

Schuster RM, Potter K, Vandrey R, Hareli M, Gilman J, Schoenfeld D, Evins AE. Urinary 11-nor-9-carboxy-tetrahydrocannabinol elimination in adolescent and young adult cannabis users during one month of sustained and biochemically-verified abstinence. J Psychopharmacol. 2020 Feb;34(2):197-210. doi: 10.1177/0269881119872206. Epub 2019 Sep 19.

Schuster RM, Gilman J, Schoenfeld D, Evenden J, Hareli M, Ulysse C, Nip E, Hanly A, Zhang H, Evins AE. One Month of Cannabis Abstinence in Adolescents and Young Adults Is Associated With Improved Memory. J Clin Psychiatry. 2018 Oct 30;79(6):17m11977. doi: 10.4088/JCP.17m11977.