Behavioral Pharmacology of Cannabis in Older Adults

The overarching aims of this pilot study are to determine the dose-related effects of cannabis and explore feasibility and acceptability of conducting a rigorous behavioral pharmacology study in this population. Using a within-subject design in older adults (55-70 years), this study will (1) determine acute dose-related effects of cannabis on physiological, subjective, cognitive, and psychomotor measures and (2) explore acceptability/feasibility of this approach among older adults in order to refine procedures for future studies. Volunteers (55-70 years) will undergo three 7.5-hour experimental sessions conducted one week apart, in which they receive cannabis containing various oral doses of tetrahydrocannabinol (THC) / cannabidiol (CBD) administered in a brownie formulation and the following are assessed: 1) self-reported and/or observer ratings of positive and negative subjective effects; 2) performance effects, measured by reaction time, coordination, and cognitive impairment; and 3) cardiovascular effects. Participants will be contacted the day after each session for feedback on the acceptability of session length, types, number and duration of tasks and any adverse events. Reasons for dropout will also be sought to determine whether study procedures impacted attrition. Findings will: 1) provide investigative team with the hands-on research cannabis research experience; 2) elucidate the optimal THC dose range; and 3) determine the most feasible/acceptable study design in older adults that will inform further rigorous studies examining acute and chronic administration of cannabis formulations among older adults.

Inclusion criteria

• Self-reported history of marijuana use with no serious adverse effects
• Negative urine toxicology screen for psychoactive drugs (cocaine, fentanyl, methadone, opiates, buprenorphine, methamphetamine, amphetamines, barbiturates, oxycodone, benzodiazepines, phencyclidine, and THC) and CBD
• Negative breath alcohol concentration
• Report ≥1 year abstinence from nicotine and tobacco
• Report ≥1 month of abstinence from THC- and CBD- containing products and be willing to abstain from these products for the study duration
• Blood pressure (BP) reading ≤140/90 and ≥110/70 at the time of screening
• Read and understand English (because assessments are validated in English)
• Menopause as defined as no reported menstruation for ≥12 months (females only)
• Negative urine pregnancy test (females only)
• Stable medical conditions controlled by non-psychoactive medications that do not alter THC/CBD metabolism (e.g., hypertension under control with certain antihypertensives; type II diabetes controlled by metformin)

Exclusion criteria

• A history of moderate to severe substance use disorders (SUDs) (except tobacco), according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5), and no recent history (≥1 year) of SUD
• Current tobacco/nicotine use
• ECG abnormalities at screening including but not limited to: bradycardia (<55 beats per minute); prolonged QTc interval (>450 msec); Wolff-Parkinson White syndrome; wide complex tachycardia; 2nd degree, Mobitz type II heart block; 3rd degree heart block; left or right bundle branch block; pre-existing severe gastrointestinal narrowing (pathologic or iatrogenic)
• Have a serious and uncontrolled medical condition (major cardiovascular, renal, endocrine, or hepatic disorder) including a history of serious head trauma or neurological disorder (e.g., seizure disorder)
• Meet Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 criteria for lifetime psychosis, schizophrenia, or bipolar disorder or current major depressive disorder, suicidality (e.g., last month suicidal ideation or suicide attempt in past year, as measured by Columbia Suicide Severity Rating Scale) or have significant psychiatric symptoms of another disorder
• Diagnosis of a cognitive disorder (Alzheimer's Disease, dementia) or a score of <25 on the Montreal Cognitive Assessment (MoCA) for Dementia during screening
• Currently taking any prescribed medication for a psychiatric disorder
• Current use of over-the-counter medication or prescription psychoactive drugs that would be expected to have major interaction with THC (e.g., warfarin, serotonin reuptake inhibitors, tricyclic antidepressants, sildenafil).
• Reported cancer-related fibromyalgia or neuropathic pain conditions
• Have a medical contraindication to, or prior serious adverse events from, cannabis or brownie ingredients (e.g., food sensitivities to gluten/wheat, chocolate, eggs)
• Consume the equivalent of >2 cups of coffee/day (to reduce variability related to metabolic interactions with caffeine)
• Have any of the following: uncontrolled hypertension (i.e., systolic >140 mm Hg and/or diastolic >90 mm Hg on three separate occasions; systolic >170 or diastolic >110 on any occasion), liver function tests >3 times normal, blood urea Nitrogen and Creatinine outside normal range
• Have a physical limitation that will interfere with completing study tasks
• Have child-bearing potential (women)