Cannabis, Neuroinflammation, and Suicidal Ideation: A Supplemental Brain Imaging Study

Inclusion Criteria: * Eligible for, and provided written informed consent to participate in, the Parent Study (NCT06381180) and to be contacted regarding 'future research studies.' * Able/willing to provide written informed consent to participate in the Neuroimaging Study. Exclusion Criteria (eligible if the subject does not meet both criteria): * Contraindications for MRI scanning include, but are not limited to: as braces, pacemaker, implanted metal (self-report MR screening form and ferromagnetic detectors) or medical conditions that prevent comfortable MRI scanning procedures, e.g., inability to lay supine for 60 minutes, claustrophobia, or body weight \> 275lbs. * Contraindications for PET \[18F\]FETrp imaging include, but are not limited to: chronic medical conditions that alter radiotracer pharmacokinetic properties, e.g, Diabetes I/II (or uncontrolled glucose levels \[\>200mg/dl non-fasting\]), abnormal BMI (\<18.5 or \> 35kg/m2), autoimmune diseases, or other chronic inflammatory conditions, or take medications (3+ days/week) that will alter radiotracer binding, e.g., glucose stabilizing medications, proton-pump inhibitors, or anti-inflammatory agents, or have medical conditions that prevent comfortable PET scanning procedures, e.g., inability to lay supine for \~75 minutes, tolerate a radial vein catheter and up to 35ml of whole blood drawn, or body weight \> 275lbs.