Pilot Trial of Contingency Management for Long-Term Cannabis Abstinence

Study Overview
=================
Brief Summary
-----------------
This study is a critically important first-of-its-kind investigation of the potential research utility of using contingency management to examine long-term changes in cannabis use with six months of abstinence. These pilot data will inform a later trial which will focus on testing the longitudinal relationships between adolescent cognition and cannabis use, questions of high and growing public health significance given adolescents' increased access to cannabis with legalization.

Official Title
-----------------
Pilot Trial on the Efficacy of Contingency Management for Six Months of Cannabis Abstinence Among Adolescents

Conditions
-----------------
Cannabis Use, Adolescent Behavior

Intervention / Treatment
-----------------
* Behavioral: Contingency Management


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Male and female adolescents actively enrolled in a middle or high school in the Boston area who are between the ages of 13 and 19 (inclusive); Average use of cannabis at least 3 times per week during the 3 months prior to study enrollment; Cannabis use reported within 7 days of study enrollment; No immediate plan to discontinue cannabis use; Have a parent or legal guardian who is competent 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 willing to provide written informed consent (if age 18 or older); Able to communicate in English language; Have a parent/guardian who can communicate in English language; Able to commit to 27 study visits in approximately 6 months; Able to safely participate in the protocol and appropriate for outpatient level of care, in the opinion of the investigator. Exclusion Criteria: - Any severe developmental delays (including, but not limited to, Autism Spectrum Disorder, Intellectual Disability, and Down Syndrome).

Ages Eligible for Study
-----------------
Minimum Age: 13 Years
Maximum Age: 19 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Abstinent<br> | Behavioral: Contingency Management<br>* Six months of cannabis abstinence will be incentivized using a standard contingency management approach involving an escalating schedule of payment for abstinence and attendance.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Continuous abstinence via progressive declines in urine THCCOOH | Cannabis abstinence will be indexed by progressively decreasing quantitative levels of 11-nor-delta-9-THC-9-carboxylic acid (THCCOOH), the primary cannabis metabolite, in urine. Residual cannabinoid excretion will be differentiated from new cannabis exposure using a statistical model developed by Schwilke and colleagues (2011). This model was empirically derived from urine CN-THCCOOH concentration ratios of consecutively collected specimen pairs (current specimen/prior specimen). This model takes into account the time between collection of specimens, which enhances the accuracy of prediction of new cannabis use. This formula yields an expected CN-THCCOOH ratio associated with specimen pairs during abstinence, and observed ratios that exceed this expected value are interpreted as new cannabis use. | Six months |