Understanding Effects of Cannabis Use and Abstinence on Neural Glutamate Homeostasis

Who can take part

• HC and CUD Group:
• Voluntary, written, informed consent
• Physically healthy by medical history, physical, neurological, ECG and laboratory exams
• No personal or first-degree relative history of psychiatric disorders (outside of cannabis use for CUD group)
• Full scale and verbal IQs > 80 (Wechsler Adult Intelligence Scale, Fourth Edition; WAIS-IV); CUD group:
• Cannabis use disorder as determined by DSM-5 structured interviews
• Urine toxicology evidence of cannabinoid use; HC group:
• lifetime cannabis exposure less than 20 times
• no cannabis use in the past 2 years by self-report
• a negative urine drug screen

Who cannot take part

• Urine toxicology results positive for other drugs such as opiates / opiate metabolites (e.g., methadone, buprenorphine, etc.)
• Current use of psychotropic and/or potentially psychoactive prescription medications
• Medical contraindications to MRI imaging (e.g., ferromagnetic implants/foreign bodies, claustrophobia, etc.)
• Other substance use disorder within 1 year, except for nicotine
• Another primary DSM-5 Axis I major psychiatric disorder (e.g., schizophrenia, bipolar disorder, major depression, etc.) per SCID-5
• A history of significant medical (cardiac, infectious, metabolic) or neurological illness (e.g., cerebrovascular disease, traumatic brain injury)
• A history of seizures/epilepsy
• Subjects will be excluded for major medical or neurological illness or laboratories consistent with these illnesses or suggesting contraindication to PET or MR imaging
• Pregnancy or breastfeeding (women)