Determining the Effect of Six Weeks of Cannabis Abstinence on Fronto- Striatal fMRI Markers in Adolescents With Cannabis Use Disorder (ABSCAN)

Inclusion Criteria:

* Male and female adolescents between the ages of 15 and 18 (inclusive).
* Have a parent or legal guardian who is able and willing to provide written informed consent.
* Competent and willing to provide written informed assent (participants \<18) or consent (participants=18).
* Native English speaker.
* Have a parent or legal guardian who is fluent in English.
* Able to commit to 9 study visits in approximately 60 days (6 weeks).
* Able to safely participate in the protocol and appropriate for outpatient level of care, in the opinion of the PI.
* No active psychosis or current use of antipsychotic medications.
* Participants taking psychotropic medications will be included if the medications have been stable for 6 weeks and are expected to remain stable for the duration of their study participation (i.e., through the third MRI).
* For CB-Abst (n=24) and CB-Mon (n=20) groups: at least 5 days of use per week on average in the past two months and meet DSM-V cannabis use disorder (CUD; at least Mild) criteria. Cannabis use reported within seven days of baseline visit. Positive qualitative urine toxicology test at baseline for THC. No immediate plan to discontinue cannabis use.
* For Con (n=20): no lifetime history of cannabis use. Negative qualitative urine toxicology test at baseline for THC. No immediate plans to begin cannabis use.
* For optional components (A: daily remote assessments during and/or (B) after treatment period): access to a personal device (e.g., smartphone or computer) on which to complete daily remote assessments.

Exclusion Criteria:

* Past twelve-month history of substance use disorders (except for Cannabis Use Disorder in CB-Abst and CB-Mon), assessed via semi-structured psychodiagnostics interview at baseline.
* Contraindications for MRI (ascertained via participant and parent report), including but not limited to:

  1. Metal implants such as surgical clips or pacemakers, or history of working with metal, unless the possibility of a metal fragment can be ruled out by recent orbital scans.
  2. Prior head trauma with neurological sequelae.
  3. Claustrophobia.
  4. Weight incompatible with MRI safety.
  5. Pregnancy.
* Previous or current diagnosis of psychosis, cognitive disability, or bipolar disorder.
* Active suicidality.
* Taking a psychotropic medication that has not reached stability criterion (same medication type and dose for 6 weeks with no planned changes over the study period).
* Any other medical or psychiatric condition deemed serious or contraindicated for any study procedures by Dr. Tervo-Clemmens.