Medical Marijuana Studies

CannaMD is committed to fostering evidence-based discussion of medical cannabis research and, in the interest of this goal, has curated a number of research studies organized by medical condition. If you are a doctor, please see our Physician Resources page for more information.

ALS (Lou Gehrig’s)

According to a 2010 study published by Rehabilitation Medicine and Palliative Care:

“Ideally, a multi-drug regimen, including glutamate antagonists, antioxidants, a centrally acting anti-inflammatory agent, microglial cell modulators (including tumor necrosis factor alpha [TNF-a] inhibitors), an antiapoptotic agent, one or more neurotrophic growth factors, and a mitochondrial function-enhancing agent would be required to comprehensively address the known pathophysiology of ALS.

Remarkably, cannabis appears to have activity in all of those areas. Preclinical data indicate that cannabis has powerful antioxidative, anti-inflammatory, and neuroprotective effects.”

Read More ALS & Cannabis Studies


According to a recent survey of over 900 cancer patients, less than 15% received information about medical marijuana from their physician or nurse – despite acknowledgement from the National Cancer Institute that cannabis treats a wide variety of disease symptoms and “has been shown to kill cancer cells.”

Research suggests cannabis may exert anti-cancer effects by causing cell death, modulating cell-signaling pathways, and inhibiting tumor invasion. For instance, a 2011 study of cannabidiol (CBD) found that CBD kills breast cancer cells by inducing endoplasmic reticulum stress and inhibiting cell-signaling. Likewise, colon cancer studies show that CBD has a cancer-protective effect and reduces cell proliferation.

Read More Cancer & Cannabis Studies

Crohn’s Disease

A 2013 Gastroenterology and Hepatology study randomly assigned Crohn’s disease patients who didn’t respond to other treatments (including steroids, immunomodulators, and anti-tumor necrosis factor-α agents) to smoke either cannabis cigarettes with or without 9-tetrahydrocannabinol (THC), known as the psychoactive compound in marijuana.

Study results showed complete remission was achieved by 5 of 11 subjects in the cannabis group (45%) and 1 of 10 in the placebo group (10%). A clinical response was observed in 10 of 11 subjects in the cannabis group (90%) and 4 of 10 in the placebo group (40%). Three patients in the cannabis group were weaned from steroid dependency.

Subjects receiving cannabis reported improved appetite and sleep, with no significant side effects.

Read More Crohn’s & Cannabis Studies


In a randomized double-blind, placebo-controlled trial performed at 30 clinic centers, researchers found that the addition of CBD to traditional seizure medication significantly decreased the rate of drop (or atonic) seizures. Specifically, study results showed that in a group of 225 people, drop seizures decreased from baseline by 41.9% in the 20-mg CBD group, 37.2% in the 10-mg CBD group, and 17.2% in the placebo group.

Read More Epilepsy & Cannabis Studies


While researchers are torn on what causes marijuana’s intraocular pressure (IOP) lowering effect – some think it’s related to the plant’s ability to lower blood pressure while others suggest the drug acts on cannabinoid receptors in the eye, decreasing fluid production (instead of directly altering pressure) – one thing is certain:

Marijuana has been shown to consistently lower IOP approximately 25% in the majority (60-65%) of both glaucoma and non-glaucoma patients.

Read More Glaucoma & Cannabis Studies


While it’s unclear how exactly cannabis exerts its influence on HIV/AIDS (study authors describe the question as “complicated due to the multiplicity of cannabinoid-mediated effects”), several lines of evidence indicate that cannabinoid immunomodulation results from cell-mediated events including attenuated cytokine production, decreased inflammatory cell recruitment, and protection from injury resulting from release of toxic mediators by infected cells.

Researchers are also exploring the possibility that marijuana lowers viral replication by mediating neuroinflammation. Additional studies suggest cannabinoid receptor agonists may even work directly to suppress HIV-replication.

Read More HIV/AIDS & Cannabis Studies

Multiple Sclerosis

In 2012, researchers randomly assigned patients with stable MS either an oral cannabis extract or a placebo. After 12 weeks, patients who received the cannabis extract reported a twofold improvement in muscle stiffness compared to those who received a placebo. Improvements were also noted in body pain, spasms, and sleep quality.

Well-controlled clinic trials involving Nabiximols (an oral cannabis spray) lend additional support.

Read More Multiple Sclerosis & Cannabis Studies

Parkinson’s disease

Research suggests that cannabinoids are neuroprotective in acute and chronic neurodegeneration and can delay or even stop progressive degeneration of the brain dopaminergic system, a process that cannot be prevented currently.

And, while current Parkinson’s medications – such as levodepa – only treat motor symptoms (and often include severe side-effects, such as motor fluctuations and dyskinesia), studies show cannabis effectively addresses non-motor symptoms, as well.

Read More Parkinson’s & Cannabis Studies

Post-Traumatic Stress Disorder (PTSD)

Studies suggest PTSD patients may be deficient in anadamine, an endogenous cannabinoid compound. This deficiency could skew performance of cannabinoid receptor, CB-1 – which is charged with deactivating traumatic memories and helping us to forget. Scientists claim CBD delays the re-uptake of anadamine and its inhibition by certain enzymes.

A 2016 Frontiers in Pharmacology study found that CBD may also reduce learned fear – a condition that triggers the fight or flight response at inappropriate times – by decreasing fear expression, disrupting memory reconsolidation, and enhancing extinction (the process by which exposure therapy inhibits learned fear).

On top of that, patients also report better sleep, increased appetite, and pain relief.

Read More PTSD & Cannabis Studies

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