Of all the reasons to reform medical marijuana laws, one of them is a little counter-intuitive: we don't actually know how useful medical marijuana really is. It's been approved for a range of potential conditions; in New York, for example, it can be sought by sufferers of Parkinson's, HIV/AIDS, epilepsy, and multiple sclerosis. Particularly in the United States, though, legal restrictions and limited funding have made it hard to test its actual efficacy. In a study published today by the journal Neurology, researchers from the Netherlands say that patients with Alzheimer's or other forms of dementia might want to look beyond pot... at least for the time being.
Early studies in mice and humans have suggested that THC (naturally found in marijuana) could help alleviate some symptoms that accompany dementia, including agitation and motor control problems. Study co-author Marcel Olde Rikkert, a geriatrics researcher from Radboud Univerity Medical Centre, says that these were either too small or not well-controlled enough to definitively show a benefit, but they were enough to warrant a more detailed study, especially because current treatments like antipsychotics can have dangerous side effects for aging patients.
The placebo group showed about as much improvement
The team recruited 50 patients with dementia and without other severe illnesses, putting 26 on a placebo and 24 on 4.5 milligrams of THC (in pill form) daily. The study was double-blinded, so neither the researchers nor the patients knew which group was which. At the beginning, the patients' caregivers scored their levels of symptoms like agitation and aggression. After two and three weeks, they repeated the survey, letting researchers compare the scores.
The researchers noted that scores for patients using THC improved over the course of the study. Unfortunately, so did the placebo recipients — there was no statistically significant difference between the groups. Patients weren't getting as high a dose of THC as someone smoking recreationally or taking it for other medical purposes, but Olde Rikkert says it was comparable to previous studies about dementia. "We suggest that former results were biased by not being strictly blinded or otherwise biased," he says.
This doesn't mean that it's time to give up on testing THC for dementia sufferers. The drug was tolerated well, says Olde Rikkert, making it potentially safe to try in higher doses that could have real effects. "There were no side effects, no ‘high’ feelings, and with very sensitive gait and balance measures we could only find minor changes." It also doesn't tell us much about the potential benefits in other areas, like multiple sclerosis pain — which Olde Rikkert cites as a better-researched example — and epilepsy. But it does show that despite the broad potential of medical marijuana, we're still in the early stages of figuring out how to use it.