What the Research Says About Marijuana

Though marijuana has been around and in use for hundreds of years, research into the depth of the healing powers of this plant are only just now picking up speed. 

Due to the risk of legal consequences, researchers and medical professionals kept their distance from cannabis over the last 125 years. As early as 1906, marijuana was mislabeled as a poison and, by the 1920s, most states in the United States had instated outright prohibition. In the mid-1930s, cannabis was regulated as a drug in every state, including 35 states that adopted the Uniform State Narcotic Drug Act. But, it was perhaps the passage of the Controlled Substances Act in 1970 that did the most damage to research into marijuana and its potential. 

To this day, efforts to reschedule the plant have failed, even though, statistically, one in every 10 citizens in the U.S. are using marijuana legally under state laws.  In the states where marijuana is legal, revenue for cannabis in the U.S. alone is expected to surpass that of the NBA (National Basketball Association) in 2020 and is on target to surpass sales of prescription pain pills by 2024. 

Even though marijuana used for medical purposes – as well as recreationally in states where it is legal – has grown quickly, the miraculous plant is far from reaching full knowledge for its potential. 

As states legalize marijuana, research has begun to flourish within the United States. Data collected from patient use is fueling further study. In addition, medical research from all over the globe is revealing treatment possibilities and effectiveness of marijuana for medicinal purposes.

Following is an overview of some of the promising results.


The Minnesota Department of Health published a report in the Journal of Oncology Practice showing that patients enrolled in Minnesota’s medical marijuana program showed significant improvements in symptoms related to cancer and cancer treatment including reducing symptoms like anxiety, lack of appetite, depression, inability to sleep, fatigue, nausea, and pain.

Chronic Pain

The National Academies of Sciences reported that, “there is conclusive and substantial evidence that cannabis or cannabinoids are effective: 1) for the treatment of chronic pain in adults; 2) as antiemetics in the treatment of chemotherapy-induced nausea, and 3) for improving patient-reported multiple sclerosis spasticity symptoms.” The institution further reported that “there is no conclusive evidence that the drug effects of marijuana are casually linked to subsequent abuse of other drugs.”

Opioid Use

A growing body of research indicates that accessibility to medical marijuana significantly reduces opioid use. Among those recent studies, one conducted at Irving Medical Center at Columbia University and published in the American Academy of Orthopedic Surgeons states with active medical marijuana programs saw certain opioid prescription rates drop nearly 20 percent compared to states without medical marijuana programs. The researchers found that medical marijuana is a particularly appealing alternative pain medication, “… because of its efficacy in treatment of chronic and acute pain and its potential for replacing and/or reducing opioid treatment.”


The first randomized placebo-controlled double-blind trial of CBD in Dravet syndrome was published in the New England Journal of Medicine in May 2017. Conducted at 23 centers in the USA and Europe, this trial included 120 patients with an established diagnosis of Dravet syndrome (mean age 9.8 years, range 2.3 to 18.4 years) were randomized to receive placebo or 20 mg/kg/day CBD in two divided daily administrations. All patients had at least 4 convulsive seizures during a preceding 4-week baseline, and CBD or placebo were added on to pre-existing medications. The duration of treatment was 14 weeks, including a 2-week-titration phase. Compared with baseline, the median monthly frequency of convulsive seizures (defined as the sum of tonic-clonic, tonic, clonic, and atonic seizures) decreased from 12.4 to 5.9 in the CBD group, and from 14.9 to 14.1 in the placebo group. Three patients (5%) became seizure-free during the treatment period in the CBD group, compared with none in the placebo group.

Chrons Disease

Some research suggests that the endocannabinoid system (ECS) might play a role in gut health. Particularly, inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, might be influenced in part by alterations in the ECS, as this system might modulate inflammatory responses. In addition, research shows that levels of anandamide, an endocannabinoid, are much lower in the inflamed gut mucosa of those with IBD than in healthy gut tissue. One retrospective study in Israel asked 30 patients with Crohn’s disease about their disease severity before and after using cannabis and found great improvements. They found that 70% of the patients experienced a decrease in Crohn’s disease symptom severity when using cannabis, and that many were able to reduce or eliminate the medications that they were using.


The emerging literature on the effects of endocannabinoids and new cannabinoid-derived molecules on MS could lead to the development of promising models for the therapy and management of disabling symptoms of the disease. Considering that current treatments of MS are partially effective and have risks of side effects not easily tolerated by patients, the development of new synthetic endocannabinoids or cannabinoid-derived drugs could represent an alternative strategy to pursue. A crucial point that deserves further investigation is the full assessment of the possible psychotropic side effects that represent the limits to the use of cannabimimetic drugs in MS therapy. The possibility of overcoming these side effects to develop novel approaches represents the main open question on the use of cannabinoids as new therapeutic drugs for the treatment of MS.

Find out more

The Healing Clinics follows research and studies in medical marijuana and will share the latest results in a series titled “What the Research Says.” Please subscribe to our blog or newsletter to find out more and to receive alerts when new information is available.


Prescription Rx versus Medical Marijuana: https://mjbizdaily.com/chart-retail-cannabis-sales-surpass-nba-revenue-approach-prescription-pain-meds/

Pain Relief: https://www.nih.gov/news-events/news-releases/nih-investigate-minor-cannabinoids-terpenes-potential-pain-relieving-properties

Pain Relief: https://www.cnet.com/health/cbd-for-pain-relief-what-the-science-says/

Pain Treatment: https://www.marijuanamoment.net/feds-promote-funding-for-studies-on-marijuana-as-pain-treatment-alternative-to-opioids/

Seizures: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5767492/

Chrons Disease: https://badgut.org/information-centre/a-z-digestive-topics/cannabis/

Spasticity and MS: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2626929/