Ask the Expert: Medical Marijuana – What Do We Know?

With many states legalizing the use of medical marijuana (compounds called cannabinoids), and some even making it legal for recreational use, you might be wondering if it would be beneficial to people with Lewy body dementias (LBD).  But with the severe medication sensitivities common in LBD, caution is always urged when considering any medications that can impact mood, cognition or movement.

So, what has research revealed so far about the benefits or risk of using medical marijuana in disorders like LBD? So we asked Dr. Carol Lippa, Director of the Division of Cognitive Disorders at Thomas Jefferson University and member of LBDA’s Scientific Advisory Council, to shed some light on the subject.

Laboratory research shows these agents may reduce amyloid pathology in Alzheimer’s disease, and studies done in animal models show possible behavioral benefits. However, there is no strong evidence yet that cannabinoids can slow or reverse the degenerative disease process in humans. Prior research has shown clear links between longstanding cannabis use, memory loss and psychosis.There are currently over 150 clinical trials listed on to study their use in a variety of medical conditions. However, there have been no large-scale studies demonstrating a beneficial effect of cannabinoids yet on either cognition or behavioral symptoms Alzheimer’s disease, LBD or other dementias. 

Since cannabinoids may help with some psychiatric problems, there is interest in studying these agents for certain behavioral changes experienced in LBD, such as agitation.  However, there are many different types of cannabinoids, and there is evidence that some may worsen psychosis while others may provide benefit. Oil that contain concentrations of cannabinoids (CBD oil) is gaining increased attention for the treatment of pain, particularly chronic forms of pain that do not respond to opioids, or where opioids are contraindicated.  This is relevant in LBD where pain is common but not always verbally expressed. Instead, pain may be identified through increased confusion and behavioral changes in individuals with dementia. 

The National Academies of Sciences, Engineering and Medicine recently published a report after doing a comprehensive scientific review of the existing evidence of using medical marijuana in a wide array of medical conditions. They concluded there is some limited evidence that medical marijuana is not effective for symptoms associated with dementia.

In summary, what is certain is that much more research is needed to provide the type of sound scientific evidence that guides physicians treating individuals with any type of dementia. Until then, hold off on baking up that ‘special’ batch of brownies.