Medical Marijuana Studies

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.

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.

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.

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.

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.

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.

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.