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Research has found that cannabis-derived drugs may help improve some Alzheimer’s symptoms. María Soledad Kubat/Stocksy
  • Agitation is a common problem that people with Alzheimer’s disease experience.
  • Researchers are interested in finding the best ways to manage agitation, including determining which medications may be most helpful.
  • One new study suggests that the drug dronabinol derived from cannabis could help reduce agitation in people with Alzheimer’s disease without significantly increasing the risk for adverse events.

Alzheimer’s disease is a chronic and challenging condition to manage, from its diagnosis to the symptoms that individuals experience. For example, people with Alzheimer’s disease can experience agitation that makes care and daily life difficult.

Recent study results were shared at the International Psychogeriatric Association conference that indicate cannabis could help address agitation related to Alzheimer’s disease.

In research including 75 participants over a three-week intervention period, researchers found that the drug dronabinol — a synthetic version of the psychoactive delta-9-tetrahydrocannabinol (THC) compound in cannabis — helped reduce agitation better than the placebo.

The results demonstrate that it might be helpful to use dronabinol in clinical practice for this purpose in the future.

Alzheimer’s disease is a common dementia type that can involve memory loss, changes in learning abilities, and behavioral changes. There is no one test that can diagnose Alzheimer’s disease, which can be challenging for doctors and people experiencing symptoms of Alzheimer’s disease.

Diagnosing Alzheimer’s disease can involve multiple tests, including ways to rule out other causes for the symptoms someone is experiencing.

There are blood tests available that can help with Alzheimer’s disease diagnosis. One recent study found that biomarkers in blood that are related to Alzheimer’s disease may change based on the time of day. Experts may need to take this into account when it comes to diagnosing and treating Alzheimer’s disease. It also implies that there is even more data to consider when it comes to accurately diagnosing Alzheimer’s disease.

After receiving a diagnosis of Alzheimer’s disease, it’s important for everyone to work together to address Alzheimer’s disease symptoms to come up with the best management strategies.

Agitation is a symptom related to Alzheimer’s disease. Authors of the current research note that agitation can lead to some challenging behaviors, including resisting care, trouble sleeping, and combativeness. They note that while behavioral strategies are part of agitation management, medication can also play a role.

This current research explored using the drug dronabinol, which is a synthetic version of delta-9-tetrahydrocannabinol (THC). THC is a compound in cannabis that leads to cannabis’ psychoactive effects. Dronabinol can help with nausea and vomiting and help improve appetite.

Researchers compared the use of dronabinol with placebo to see if there would be a noted reduction in agitation symptoms in participants with Alzheimer’s disease.

The placebo-controlled, double-blind trial had a three-week intervention period. All participants had dementia due to Alzheimer’s disease and were between 60 and 95 years old. Researchers excluded some individuals, such as those taking lithium and those who already had baseline delirium, which is the temporary cognitive and behavioral changes that can occur because someone is taking medication or has a certain illness.

Researchers used several assessment scales to look at participant behavior, including the Pittsburgh agitation scale (PAS) and Neuropsychiatric Inventory, Clinical Version (NPI-C). They utilized questionnaires to look at drug effects and side effects. They also monitored participants for adverse events.

Researchers recruited 75 participants from five different clinical research sites, and 63 participants completed the whole study. The research included inpatient and outpatient participants. Throughout the timeframe, there were no significant differences in adverse events between the control group and placebo group. Three severe adverse events occurred in the intervention group and none in the placebo group, so this was not enough for researchers to make a valid statistical comparison.

Over three weeks, participants received five mg of dronabinol twice a day or a placebo. Overall, researchers found that dronabinol was a safe intervention for participants and helped decrease agitation better than the placebo.

Study author Paul B. Rosenberg, M.D. Professor of Psychiatry and Behavioral Sciences with the Johns Hopkins School of Medicine, noted the following highlights of the study’s findings to Medical News Today:

“We found that dronabinol (a prescription form of THC) was safe and effective in treating agitation in Alzheimer’s disease over a 3-week period in 75 patients. This is particularly relevant because this was very much a ‘real-world’ population in that we did not exclude patients with advanced dementia or taking other medications, so it is all the more impressive that we saw the benefit.”

This study does have limitations. First, the full study has not currently been published and is not available to the general public. Second, it only involved a small number of participants, so larger studies can help confirm the findings. The time of the intervention was only three weeks, so it does not address the potential long-term effects.

Participants in both intervention and placebo groups were also receiving other antipsychotic and antidepressant treatments, which could have impacted the results.

Since the data came from multiple facilities, it’s possible there were inconsistencies in assessments and differences between inpatient and outpatient participants. The trial itself was also affected by the COVID-19 shutdown. One measurement of cognitive function was higher in participants who completed the study than those who did not. 65% of participants were female, so future studies could include more male participants.

It is important to note that dronabinol specifically addressed a symptom related to Alzheimer’s disease, not Alzheimer’s disease itself.

David Merrill, MD, PhD, a board certified geriatric psychiatrist at Providence Saint John’s Health Center in Santa Monica, CA, who was not involved in the study, noted the following:

“While the treatment did show a statistically significant reduction in agitation symptoms, the patients remained with significant symptoms, and the underlying causes of the disease process are not addressed by the drug. The treatment is symptomatic. Similar symptomatic treatments also already exist, and though the authors cite potential side effects of these other drug options, dronabinol itself is not without risks.”

Overall, the study demonstrates that dronabinol may help manage agitation in people with Alzheimer’s disease. If future research confirms the findings, this could lead to dronabinol being used in clinical practice for agitation.

Rosenberg noted the following about continued research in this area:

“We need to determine whether response is long lasting, and we need to study cannabis products available at dispensaries. This latter is very challenging scientifically but very important since we know patients and families are using these products.”