A Pilot Trial of Nabilone for the Treatment of Obesity

Inclusion Criteria: * Obese adults (BMI \> 30.0 kg/m2). * For the optional imaging component of the study, a maximum weight (315 lbs) and a maximum girth in line with capacity of the machine (60 cm horizontal and 45 cm vertical; therefore, circumference of scanner is 166.6 cm) * For women of reproductive potential (WORP) and men whose sexual partners are WORP: use of adequate methods of contraception (effective barrier methods such as male condoms, female condoms, cervical caps, diaphragms, or contraceptive sponges; and highly effective methods of contraception such as oral hormonal contraceptives, intrauterine devices (IUDs), vasectomy, or tubal ligation) * AST/ALT, bilirubin, and kidney function tests within normal limits at screening. Exclusion Criteria: * Unstable gastrointestinal, respiratory, endocrinological, cardiovascular or cerebrovascular diseases that would prevent participation in the trial at QI (or its delegate) discretion, * Unstable major psychiatric disorder(s) (i.e. Axis I Disorders) that would prevent participation in the trial at QI (or its delegate) discretion, * Current substance use disorders (DSM-V) (excluding tobacco and caffeine), * History of, or current neurological illnesses, that would prevent participation in the trial, * Current use or use during the previous month of antipsychotic medications, * Learning disability, amnesia or other conditions that impede memory and attention, * Visual impairments that prevent participation in the study, * Personal or family history of schizophrenia, or psychosis (or psychosis-related) disorders, * Antibiotic use in the last 4 weeks, * Previous bariatric surgery, * Current use or use in the past month of other weight-loss pharmaceuticals, * Cannabis use in last 6 months, * Known sensitivity to cannabis or other cannabinoid agents, * Pregnancy or lactation (females), and * For the optional imaging component of the study: * Presence of metal implants or objects unsafe for MRI such as cardiac pacemakers, metal fragments in the eye, and aneurysm clips in your brain * Piercings or jewelry that are unable to be removed * Tattoos inked with metal dyes