Overview of Medical Marijuana Research

Attitudes toward cannabis are shifting as credible medical research efforts continue to reveal the plant’s exciting therapeutic potential. Ample studies have shown cannabis could be a viable treatment option for alleviating neuropathic pain, nausea and spasms and for providing anti-inflammatory and healing effects for those with serious conditions like multiple sclerosis, arthritis, inflammatory bowel disease, HIV/AIDS, diabetes, cancer and spinal cord injuries. No longer unfairly brushed aside as simply a recreational drug, marijuana and its remedial capabilities continue to be investigated through viable medical studies.

Groundbreaking Findings About Medical Marijuana

Over the past decade, medical research has made intriguing discoveries about cannabis and its therapeutic effects. Studies have shown that medical marijuana:

  • has anti-cancer effects
  • can slow the progression of Alzheimer’s and Parkinson’s diseases
  • reduces the debilitating seizures caused by epilepsy
  • reduces spasms experienced by those with multiple sclerosis
  • curtails the pain and nausea caused by chemotherapy and traditional AIDS/HIV treatments so that patients can more comfortably continue medical care
  • minimizes the neurological damage caused by spinal cord and traumatic brain injuries*

*Sources: (McAllister, Soroceanu & Desprez, 2015) (Iuvone, et al., 2004) (More & Choi, 2015) (Blair, Deshpande & DeLorenzo, 2015) (Lakhan & Rowland, 2009) (Bar-Sela, et al., 2015) (Abrams, et al., 2007) (Latini, et al., 2014) (Mechoulam & Shohami, 2007).

Challenges Facing Research

Marijuana’s therapeutic effects have been scientifically explored for many years. It’s first documented use as a therapeutic agent dates back to 2,700 BC and medical journals from America and Europe published more than 100 articles on cannabis and its beneficial effects between the years of 1840 and 1900 (Zuardi, 2006). Marijuana was even a common component of the medical field in the United States up until 1942 when, despite objections by the American Medical Association, congress passed the Marihuana Tax Act of 1937, which federally restricted cannabis (Aggarwal, et al., 2009). The federal restriction was then later affirmed when cannabis was classified as a Schedule 1 substance under the Controlled Substances Act of 1970.

Cannabis’ Schedule 1 status causes hurdles for researchers, who must acquire a Schedule 1 research registration from the U.S. Drug Enforcement Administration and typically a Schedule 1 research license from the state-controlled drugs agency. Researchers also have to obtain their cannabis material from the National Institute on Drug Abuse (NIDA), the sole source of research-grade cannabis that is federally lawful. These requirements can take three to six months, pushing out the starting date of research projects. These obstacles have hindered the volume of human clinical research and thus handicapped the collection of data on effectiveness, dosage, safety and delivery systems.

Exciting Findings Nevertheless

Despite the logistical difficulties, medical research has shown true promise for cannabis. Research into the pharmacology of individual cannabinoids began in the 1940s, and increased markedly in the mid-1960s and early 1970s when scientists were able to identify the first cannabinoid (Pertwee, 2006). Early animal experiments and human studies showed cannabis’ ability to elevate mood, appetite and pain, but an explanation of how it brought about these benefits remained unknown.

Findings began to flourish, however, in 1988 when scientists discovered the endocannabinoid system, a sophisticated group of neuromodulators, receptors and signaling pathways that regulate numerous physiological processes like mood, memory, pain, appetite and movement (Pertwee, 2006). While cannabis contains more than 100 cannabinoids, it’s two in particular, tetrahydrocannabinol (THC) and cannabidiol (CBD), that have been found to interact with the body’s endocannabinoid system. THC and CBD stimulate the cannabinoid receptors, CB1 and CB2, which in turn work to regulate a myriad of neurotransmitter systems. CB1 receptors are located in the central nervous system (brain) and other tissues like the kidneys, liver, digestive tract, lungs and eyes. CB2 receptors are primarily found in tissues associated with the immune system.

The identification of these cannabinoid receptors triggered additional studies that explored the relationship between THC and CBD and the endocannabinoid system and the regulatory role it plays in health and disease (Pacher, Batkai & Kunos, 2006) (Di Marzo, Bifulco & De Petrocellis, 2004). Throughout the past two decades, studies have shown that modulating the activity of the endocannabinoid system with the cannabinoids found in cannabis offer therapeutic benefits in a wide range of diseases without debilitating side effects. The upregulation of the endocannabinoid system with THC and CBD, for example, has shown to reduce the severity of symptoms like neuropathic pain and muscle spasms and slow the progression of diseases like multiple sclerosis, epilepsy, Parkinson’s disease, spinal cord injury, osteoporosis, glaucoma, hypertension, schizophrenia, post-traumatic stress disorder, intestinal diseases, cardiovascular diseases, mood and anxiety disorders, traumatic head injury, and even cancer (Di Marzo, Bifulco & De Petrocellis, 2004) (Pertwee, 2006) (Pacher, Batkai & Kunos, 2006). In addition, studies have shown that cannabis is more effective than older traditional medications like phenothiazines and antihistaminics for treating nausea and vomiting (CA).

According to Americans for Safe Access, more than 15,000 modern peer-reviewed scientific articles exploring the pharmacology of cannabis and its cannabinoids have been published by medical journals.

Looking Ahead

Cannabis research continues to face regulatory, botanical and pharmacological challenges. However, in order for cannabis to be considered for approval by the U.S. Food and Drug Administration (FDA) and to garner trust from physicians, randomized clinical trials following accepted scientific methods need to further prove the safety and effectiveness of cannabis-based medicines (Russo, Mead & Sulak, 2015). However, the recent plethora of therapeutic findings have dramatically invigorated the cannabis research field and the National Institutes of Health, the Institute of Medicine, and the American College of Physicians have all issued statements in support for further cannabis research and development (Aggarwal, et al., 2009).

Medical Marijuana Research

Here is a quick overview of what researchers have so far discovered about medical marijuana and its potential benefit for the treatment of specific conditions.

Alzheimer’s Disease

Studies have shown marijuana can help slow the production of beta-amyloid proteins, which are considered a key contributor to the progression of Alzheimer’s disease.

Amyotrophic Lateral Sclerosis (Lou Gehrig’s Disease)

Studies have shown marijuana effectively slows the progression of the disease and helps patients manage the disease’s associated symptoms.


Studies have shown marijuana to be an effective treatment for some aspects of the disorder, and several states have approved medical marijuana as a treatment.

Anxiety Disorder

Studies have shown marijuana can reduce autonomic arousal and subjective anxiety.

Arnold-Chiari Malformation

Studies have shown marijuana can help curtail the pain, sleeping problems and spasms often associated with the condition.


Studies have shown marijuana can help repair the brain’s ability to send clear signals, thus improve behavior and communication.

Bone Health

Studies have shown marijuana can boost bone density and assist in healing.

Cachexia (Wasting Syndrome)

Studies have shown marijuana boosts appetite and increases body weight and energy levels.


Studies have shown marijuana has the capability of helping cancer patients manage the nausea, pain and weight loss related to cancer treatments, and even limit the growth or kill cancer cells.

Cardiovascular Disease

Studies have shown marijuana can protect against hypertension, stroke, atherosclerosis and heart attacks by causing blood vessels to vasodilate (relax and widen).

Central Nervous System Disorders

Studies have shown marijuana provides neuroprotective effects.

Chronic Pain

Studies have shown marijuana is highly effective at lowering all types of pain, including the pain that’s shown to be resistant to other treatments.

Cirrhosis and Liver Disorders

Studies show that a cannabinoid found in marijuana can help combat the progression of cirrhosis and other liver disorders.


Studies have shown marijuana has antidepressant-like effects.


Studies have shown marijuana reduces the risk of diabetes, can help treat diabetes once its developed, and assists in the management of pain associated with the disease.


Studies have shown marijuana can reduce dystonic movements.

Early Morning Disorder

Studies have shown marijuana improves sleep.

Epilepsy (Including Dravet Syndrome, Lennox-Gastaut Syndrome,

Studies have shown a major cannabinoid found in marijuana is effective at significantly decreasing the frequency of seizures and has the potential of offering complete seizure freedom.


Studies have shown marijuana effectively lowers pain levels and improves quality of sleep in patients.

Fibrous Dysplasia

Studies have shown marijuana can help manage pain associated with the disorder.


Studies have shown marijuana decreases intraocular pressure.

Hepatitis C Virus

Studies have shown marijuana shows potential as an anti-inflammatory treatment and helps patients manage symptoms associated with the virus.

Heroin Addiction

Studies have shown marijuana reduces withdrawal symptoms and therefore can be used in the early treatment for addiction.


Studies have shown marijuana helps make side effects of HIV/AIDS treatment more manageable.


Studies have shown that marijuana helps improve the secondary symptoms associated with the condition.

Inflammatory Bowel Disease (Crohn’s Disease, Ulcerative Colitis)

Studies have shown marijuana is effective at decreasing digestive tract inflammation and in some cases can help patients achieve long-term remission.


Studies have shown marijuana stimulates leukemia cell death and assists in the management of symptoms associated with cancer and traditional cancer treatments.


Studies have shown marijuana reduces inflammation and pain caused by the disease.


Studies have shown marijuana reduces pain caused by migraines.

Mitochondrial Disease

Studies have shown marijuana is effective at helping patients manage symptoms associated with the disease.

Multiple Sclerosis

Studies have shown marijuana reduces pain and muscle spasms associated with multiple sclerosis and helps slow the disease’s progression.

Muscular Dystrophy

Studies have shown marijuana helps reduce pain and involuntary muscle contractions.

Nail-Patella Syndrome

Studies have shown marijuana can reduce pain and lower the risk and progression of glaucoma and kidney disease, which can develop from nail-patella syndrome.


Studies have shown marijuana helps curtail nausea once it’s developed and helps reduce anticipatory nausea.

Neurological Disorders

Studies have shown marijuana has neuro-protective benefits and helps reduce pain associated with the disorders.


Studies have shown marijuana can produce weight loss.

Retinal Damage

Studies have shown marijuana reduces ocular toxicity and can protect the retina from degeneration damage.

Parkinson’s Disease

Studies have shown marijuana reduces the progression of Parkinson’s disease and helps manage associated symptoms.

Post-Traumatic Stress Disorder (PTSD)

Studies have shown marijuana can lessen the emotional impact of traumatic events, reduce anxiety and fear, and improve sleep.

Rheumatoid Arthritis

Studies have shown marijuana can reduce inflammation and thus potentially help treat arthritis.


Studies have shown that cannabidiol, found in cannabis, can serve as an antipsychotic treatment.

Sickle Cell Anemia

Studies have shown marijuana lowers pain caused by the disorder and helps maintain proper blood flow.


Studies have shown marijuana effectively reduces the frequency and intensity of spasms.

Spastic Quadriplegia

Studies have shown marijuana helps patients manage spasms, seizures and pain.

Spinal Cord Disease

Studies have shown marijuana improves pain, sleep, and spasms that arise.

Spinal Cord Injuries

Studies have shown marijuana can limit neurological damage when administered shortly after the moment of trauma and later help manage pain and spasms.


Studies have shown marijuana can help reduce pain, sleeping problems and spasms associated with the condition.


Studies have shown marijuana can limit brain damage and improves recovery when administered shortly after a stroke.

Tourette’s Syndrome

Studies have shown marijuana can safely reduce the frequency of tics.

Traumatic Brain Injury (TBI)

Studies have shown marijuana can limit brain damage and improves recovery when it’s administered shortly after the traumatic blow.


Studies have shown marijuana has demonstrated antitumor effects.


Abrams, DI., Jay, CA., Shade, SB., Vizoso, H., Reda, H., Press, S., Kelly, ME., Rowbotham, MC. and Petersen, KL. (2007, February). Cannabis in painful HIV-associated sensory neuropathy: a randomized placebo-controlled trial. Neurology, 68(7), 515-21.

Aggarwal, S.K., Carter, G.T., Sullivan, M.D., ZumBrunnen, C., Morrill, R., and Mayer, J.D. (2009, May-June). Medicinal use of cannabis in the United States: historical perspectives, current trends, and future directions. Journal of Opioid Management, 5(3), 153-68.

Bar-Sela, G., Vorobeichik, M., Drawsheh, S., Omer, A., Goldberg, V., and Muller, E. (2013). The Medical Necessity for Medicinal Cannabis: Prospective, Observational Study Evaluating the Treatment in Cancer Patients on Supportive or Palliative Care. Evidence-Based Complementary and Alternative Medicine, 2013, 510392. Retrieved from http://www.hindawi.com/journals/ecam/2013/510392/

Blair, RE., Deshpande, LS., and  DeLorenzo, RJ. (2015, September). Cannabinoids: is there a potential treatment role in epilepsy? Expert Opinion on Pharmacology, 16(13), 1911-4.

Di Marzo, V., Bifulco, M., and De Petrocellis, L. (2004, September). The endocannabinoid system and its therapeutic exploitation. Nature Reviews, 3(9), 771-84.

Iuvone, T., Esposito, G., Esposito, R., Santamaria, R., Di Rosa, M., and Izzo, A.A. (2004, April). Neuroprotective effect of cannabidiol, a non-psychoactive component from Cannabis sativa, on beta-amyloid-induced toxicity in PC12 cells. Journal of Neurochemistry, 89(1), 134-41.

Kalant, H., and Porath-Waller, A.J. (2014). Clearing the smoke on cannabis: medical use of cannabis and cannabinoids. Canadian Centre on Substance Abuse. Retrieved from http://www.ccsa.ca/.

Lakhan S.E., and Rowland M. (2009). Whole plant cannabis extracts in the treatment of spasticity in multiple sclerosis: a systematic review. BMC Neurology, 9(59), doi:10.1186/1471-2377-9-59.

Latini, L., Bisicchia, E., Sasso, V., Chiurchiu, V., Cavallucci, V., Molinari, M., Maccarrone, M., and Viscomi, M.T. (2014, September 4). Cannabinoid CB2 receptor (CB2R). stimulation delays rubrospinal mitochondrial-dependent degeneration and improves functional recovery after spinal cord hemisection by ERK1/2 inactivation. Cell Death & Disease, e1404.

McAllister, S.D., Soroceanu, L., and Desprez, P.Y. (2015, June). The Antitumor Activity of Plant-Derived Non-Psychoactive Cannabinoids. Journal of Neuroimmune Pharmacology, 10(2), 255-67.

Mechoulam, R., and Shohami, E. (2007, August). Endocannabinoids and traumatic brain injury. Molecular Neurobiology, 36(1), 68-74.

Medical Cannabis Research. (2015). Americans For Safe Access. Retrieved from http://www.safeaccessnow.org/medical_cannabis_research_what_does_the_evidence_say.

More, S.V., and Choi, D.K. (2015, April). Promising cannabinoid-based therapies for Parkinson’s disease: motor symptoms to neuroprotection. Molecular Neurodegeneration, 10, 17.

Pacher, P., Batkai, S., and Kunos, G. (2006, September). The endocannabinoid system as an emerging target of pharmacotherapy. Pharmacological Reviews, 58(3), 389-462.

Pertwee, R.G. (2006, January). Cannabinoid pharmacology: the first 66 years. British Journal of Pharmacology, 147(Suppl 1), S163-S171.

Russo, E.B., Mead, A.P., and Sulak, D. (2015, April). Current Status and Future of Cannabis Research. Clinical Researcher. Retrieved from http://cannabisclinicians.org/wp-content/uploads/2015/05/Russo-et-al-Current-status-and-future-of-cannabis-research-Clin-Researcher-2015.pdf.

Zuardi, A.W. (2006, June). History of cannabis as a medicine: a review. Revista Brasileira de Psiquiatria, 28(2), 153-7.

  • October 14, 2015
  • Eve Ripley