The Effects of Different Medical Marijuana Strains on Motor and Cognitive Function in People With Multiple Sclerosis

Treatment tested

• Dronabinol

  Cannabinoid CB1 receptor agonist

Placebo or sham

• Placebo

Other measures (2)

Inclusion Criteria: * Medically diagnosed with MS * Age range 21-74 years of age * Moderate disability (Patient Determined Disease Steps score 2-6) * All participants must have a medical (red) card for medical marijuana use to treat their MS symptoms (such as neuropathic pain and spasticity), or currently be in the process of applying for a red card and be able to provide the prescription from their doctor. Exclusion Criteria: * Previous use of marijuana * A relapse of disease symptoms in the last 60 days * A condition unrelated to MS that would exacerbate fatigue, such as anemia, hypothyroidism, shiftwork-related fatigue, B12 deficiency, major sleep disorder, or major depressive disorder * Medical diagnosis or condition that makes participating in exercise training dangerous, such as major renal, pulmonary, hepatic, cardiac, gastrointestinal, HIV, cancer (other than treated basal cell cancer), other neurological disorders * History of heart attack or current diagnosis of cardiovascular disease * History of seizure disorders (or on medications known to lower seizure threshold), hydrocephalus (buildup of fluid in the brain), or diabetes * Alcohol dependence or abuse (>2 drinks/day), or present history (last six months) of drug abuse * History of significant traumatic brain injury or hydrocephalus * Pregnancy * Recent hospitalization (within the last 3 months) or enforced bed rest/sedentary state * Current participation in another research study that involves experiments on drugs or interventions which may influence motor and cognitive function.

Over the last two years, the United States has witnessed enormous change concerning the acceptance of marijuana. The number of persons with MS (PwMS) using cannabis to treat their symptoms is expected to rise, and it is important to provide clinicians and PwMS with evidence based information on the safety and effectiveness of marijuana. In addition, scientists need to identify the effects of medical marijuana as the compound action of different cannabinoids, specifically tetrahydrocannabinol (THC) and cannabidiol (CBD). The ratio of CBD to THC may have an important impact on the effects of the marijuana, which in turn may have important implications for the medical benefits. The overarching goal of this study is to advance a better understanding of the potential positive and negative effects associated with different strains of marijuana, using an interventional design. The investigators will examine three strains that differ markedly on THC potency (A. THC \<1%, CBD > 10%; B. THC >10%, CBD \< 1%; C. THC 510%, CBD 510%) to determine whether the level of THC is associated with differences in motor and cognitive functions in PwMS. One hundred PwMS will be recruited for this project and followed for 3 months following designation to one of three strains of marijuana with different ratios of CBD to THC or a placebo marijuana (THC 0%, CBD 0%). It is hypothesized that the strains with a high CBD to THC ratios will demonstrate the most benefits on measures of motor and cognitive function.