Marijuana is the term commonly used for the Cannabis sativa plant. (1) Despite being legal in 23 states and Washington, D.C., cannabis is still federally classified as a Schedule I drug, meaning that it has a high abuse potential and no medical use currently accepted by the U.S. government. (2) Other Schedule I drugs include heroin and 3,4-methylenedioxymethamphetamine (ecstasy), while cocaine and methamphetamine (meth) are Schedule II drugs, since they have an officially recognized medical use. (2)
As crazy as this may sound, it’s harder for scientists to conduct studies on marijuana than on cocaine or meth. College students routinely administer methamphetamine to rodents in their science classes, but if they are caught with cannabis, they may face serious disciplinary—or even legal—consequences.
The differences between cannabis, CBD, and THC
The terms “marijuana” and “cannabis” both refer to any of the subspecies of the whole, unprocessed Cannabis sativa plant and its basic extracts. (3) Cannabidiol (CBD) and delta-9-tetrahydrocannibidol (THC) are chemical compounds found in the cannabis plant that are of particular medical interest. These chemicals and those that resemble them are known as cannabinoids. (3) THC is the psychoactive chemical in cannabis responsible for much of the “high” that users feel; CBD, however, is non-psychoactive and does not produce the physiological responses that THC does. (4, 5)
While using unprocessed cannabis as medicine remains unapproved by the Food and Drug Administration (FDA), the FDA has approved two synthetic cannabinoid medications. These medications are dronabinol and nabilone, both of which are approved for the treatment of nausea caused by chemotherapy and to increase appetite in patients with extreme weight loss caused by AIDS. (3) However, there are numerous other areas in which cannabis and cannabinoids could prove beneficial to people’s health and well-being.
Four promising uses for medical marijuana...
Endocannabinoid receptors suggest potential targets and applications for medical cannabis
The human brain contains endocannabinoid receptors. Cannabinoids can induce either an inhibitory or excitatory response from the affected neuron by acting on these endocannabinoid receptors. These receptors bind not only the chemicals found in cannabis but also endogenous compounds—i.e., compounds that are naturally produced in the body. (6) The known functions of our bodies’ endogenous cannabinoids and endocannabinoid receptors suggest possible therapeutic targets for medical cannabis.
Endocannabinoid receptors have been linked to the regulation of appetite, pain management, neuroprotection, central regulation of motor functions, sleep, regulation of nausea and vomiting, reward-driven neurocircuitry, intraocular pressure, memory, tumor growth, and gastrointestinal motility. (7)
One specific type of endocannabinoid receptor, CB1, is known to stimulate appetite and ingestive behaviors. (7) This effect is responsible for the snacking behavior—or “munchies”—caused by recreational cannabis use. It is also the reason that cannabis can be used medically to increase the appetites of patients with AIDS or those who are undergoing chemotherapy, as mentioned before, while also reducing nausea and vomiting among those groups. Cannabis’s appetite-stimulating effects could also be used to treat age-induced anorexia in the elderly in general, and specifically for those with Alzheimer’s disease. (8) Cannabinoids may also be able to slow the disease process of Alzheimer’s by preventing inflammatory effects induced by the beta-amyloid deposition that is a hallmark of the disease. (9)
Endocannabinoid receptors have been shown to reduce pain from a variety of causes. The analgesic effects of acetaminophen can be prevented by blocking specific cannabinoid receptors. (10) Cannabis extracts containing THC alone and THC with CBD have proved effective at reducing chronic and neuropathic pain. (11) Many people with multiple sclerosis (MS) who use cannabis report a reduction in symptoms, including muscle spasticity, pain in extremities, tremor, bowel dysfunction, and walking and balance dysfunction. (12) This may be due to cannabis’s role in pain, motor control, and gastrointestinal motility.
Conditions for which medical cannabis shows the most promise
A changing legal and social environment
Once a niche area with limited scientific interest, the field of cannabis research has expanded rapidly in the last decade. Much of the research continues to focus on cannabinoids, rather than whole, unprocessed cannabis. Support for the use of whole cannabis comes from anecdotal evidence as much as from empirical scientific research, but research is slowly beginning to confirm or disprove those anecdotal claims. Cannabis’s current classification as a Schedule I drug by the U.S. government, as well as the attached social stigma, continues to limit the ability and willingness of researchers to investigate all of its possible uses. But as more states approve cannabis for medical and/or recreational use, research and funding will likely continue to expand.
The National Institutes of Health (NIH) currently provides funding to more than forty active projects in the category of Therapeutic Cannabinoid Research. (24) Projects include investigations into the potential of transdermal CBD to reduce the chance of relapse in abstinent alcoholics (25), the ability of vaporized cannabis and dronabinol to reduce neuropathic back pain (26), and the role of the endocannabinoid system in radiation and chemotherapy-induced cognitive impairment and possible methods for prevention or treatment (27), among many others.
I’m interested to hear from you now. Do you live in a state where medical cannabis is legal? Have you or someone you know found relief from one of the conditions discussed here through the use of cannabis or cannabinoids? Share your thoughts in the comments below.