August 19, 2016 7:00 AM

Despite Lack of Evidence, 10 States Allow Medical Marijuana for Alzheimer’s

A survey of state data suggests Alzheimer’s patients may be using cannabis to ease agitation. But little is known about the treatment’s efficacy.

Pain, nausea and lack of appetite may top the list of symptoms medical marijuana laws aim to ease. In 10 of the 25 states with medical marijuana laws, another symptom is on the list as well: the agitation and behavior issues often seen in people with Alzheimer’s disease.

SEE ALSO: Over Time, Marijuana Dampens Brain’s Response to Reward

That finding surprised a University of Michigan Medical School team. After all, only one high-quality trial has ever tested marijuana in agitated Alzheimer’s patients, and it showed no effect.

The team took a detailed look at public records from four of the 10 states, plus Washington, D.C., allowing medical marijuana for Alzheimer’s patients, and found that fewer than 125 patients had actually gotten such licenses.

Even so, the researchers are calling for more awareness among the physicians who care for dementia patients, so they can be ready to talk with patients and their caregivers about the issue.

Because patients with dementia almost certainly aren’t able to navigate the medical marijuana certification process for themselves, the role of caregivers is even more important, says Donovan Maust, M.D., M.S., the first author of the new study that will appear in the September issue of the American Journal of Geriatric Psychiatry.

"There is limited evidence for any of the indications that states give medical marijuana certifications for, and almost none when it comes to agitation due to Alzheimer’s or other causes of dementia."
Donovan Maust, M.D., M.S.

An increase in use?

The idea that marijuana can calm patients with dementia who get upset, confused or even violent might appeal to many families, Maust says. But the only study of any size, which used a low dose in 50 patients, showed no effect on these neuropsychiatric symptoms. A much smaller study, with just 10 participants who made it all the way through, showed a modest effect. 

Meanwhile, a number of studies have shown that marijuana use negatively affects the cognitive functions — memory, thinking and more — that people with dementia are gradually losing.

“There is limited evidence for any of the indications that states give medical marijuana certifications for, and almost none when it comes to agitation due to Alzheimer’s or other causes of dementia,” says Maust.

“But, for me, there’s a distinction with dementia, because family members or other caregivers are making decisions to use marijuana on behalf of the patient,” he adds. “While the family is also making decisions about other medications, those substances have all been through the FDA approval process, so the risks and benefits are much more clear.”

Still, the number of families seeking this certification is expected to rise because there are few good options for calming agitation in Alzheimer’s patients. Antipsychotic drugs are widely used, but research by Maust and his colleagues shows they carry high risks.

Meanwhile, Baby Boomers with more tolerant attitudes toward marijuana are heading for the prime years for the start of dementia, and more states are considering legalizing marijuana use for medical or recreational purposes.

Even since the study concluded, another state has legalized medical marijuana. Several states have certified ballot initiatives that will let voters decide this November whether that number will grow. The team will be monitoring new state laws and certification activity to examine trends.

Providers and cannabis prescriptions

Although the states that specifically allow medical marijuana certifications indicate it is only for agitation associated with Alzheimer’s, there is no process for certifying that a person actually had that condition and not another form of dementia, the research team notes.

SEE ALSO: Why Doctors Love Opioids and Hate Marijuana for Chronic Pain

That physicians have to be involved in certifying a patient before he or she can receive medical marijuana means that physicians need to be aware of the current state of medical evidence, says Maust.

“Given that these conversations will be with people who are concerned about a family member’s cognition, I would be concerned about adding in a substance that affects how the brain processes information,” says Maust.

“Instead, I would recommend turning the conversation to the specific behavior that’s making the family member or patient ask for marijuana certification. There are other strategies to deal with behaviors that are challenging, without substances. And there may be underlying conditions contributing to agitation that can be addressed, such as pain, hunger or even infections.”

Maust cites the DICE model developed by a team co-led by his colleague Helen Kales. Short for Describe, Investigate, Create and Evaluate, the approach is a framework for caregivers and health providers to work together to handle the behavioral aspects of dementia. It aims to anticipate what agitates people with dementia, and advocates the use of environmental modifications and other nonmedication interventions to avoid or minimize these factors.

Additional ongoing research among certified medical marijuana users in Michigan and beyond could help add to the understanding of the drug’s effect in people with dementia and other diagnoses. But with current federal laws — under which the drug is illegal and strictly limited for research use — it would be difficult to do a definitive study to look for signs of efficacy.