Marijuana benefits and risks
This is part two of a two-part post detailing the legalization of medical marijuana in Florida. (See Part One: Florida Legalizes Medical Marijuana) Dr. Ryan explains the benefits and risks of using medical marijuana.
Understanding Marijuana's Medical Application
Our present understanding of the effects of marijuana on humans is very limited due to decades of prohibition against medical research of cannabinoids, the active chemicals in marijuana. The cannabis sativa plant produces a complex mixture of active substances in its leaves, stems and flowers. These chemicals change levels of brain neurotransmitters affecting appetite, memory, movement, pain, demeanor and other broad brain functions.
The Benefits of Medical Marijuana
Some early tests have shown that marijuana cannabinoids reduce anxiety, nausea and certain types of pain. In persons with multiple sclerosis, muscle tightness is reduced. Patients with seizures may have better control and fewer side effects than with standard epilepsy drugs. Patients with cancer and AIDS may gain weight. Cannabinoids also reduce eye pressure in glaucoma.
Marijuana (principally a component called tetrahydrocannabinol or THC) reaches the same pleasure centers in the brain that are targeted by heroin, cocaine and alcohol, creating euphoria. Medical marijuana is usually derived from plants bred to reduce THC without losing the beneficial effects of other cannabinoids.
The Risks of Medical Marijuana and Genetic Factors
There appears to be a genetic factor in an individual's response to cannabinoids. Many users report a mellow mood, but some have paranoia, hallucinations, difficulty concentrating and memory loss, and poor coordination and motivation. Other symptoms can be fast heart rates, and high or low blood pressure. Research presented in October 2017 at a Berlin psychiatric conference shows teenage cannabis use hastens onset of schizophrenia in vulnerable individuals. The National Institute on Drug Abuse says marijuana can be addictive in susceptible people, depending on the level of THC and frequency of use, especially in teens.
Neurologic imaging of chronic marijuana users shows that multiple brain regions show low blood flow compared to non-users, especially a brain area called the hippocampus, resembling Alzheimer’s disease pathology.
Marijuana use by pregnant or breast feeding mothers is linked to lower birth weight and increased risk of both brain and behavioral problems in babies.
The Takeaway
Research efforts are proceeding, but it will be years before information about benefits and risks are better known. In the meantime, activist groups have legislatively created an unprecedented and uncontrolled trial on thousands of our fellow citizens. As a physician, I hope we are not looking at new health crisis like alcohol, tobacco and opioids.
