Trial of Dronabinol Adjunctive Treatment of Agitation in Alzheimer's Disease (THC-AD)

  • End date
    May 14, 2023
  • participants needed
  • sponsor
    Johns Hopkins University
Updated on 4 October 2022
cognitive impairment
psychiatric disorder
alzheimer's disease
neurodegenerative disorders
neuropsychiatric symptoms


Alzheimer's disease (AD) is the most prevalent neurodegenerative disease of aging. Neuropsychiatric symptoms (NPS) in AD are a major cause of burden to patients, caregivers, and society and are near-universal at some point in the AD course. One of the most troubling of these symptoms is agitation (Agit-AD), typified by a variety of problem behaviors including combativeness, yelling, pacing, lack of cooperation with care, insomnia, and restlessness. There is a great need for better interventions that target Agit-AD, a major source of patient disability as well as caregiver burden and stress, particularly in the case of moderate to severe agitation. This pilot trial could open the door to "re-purposing" Dronabinol (Marinol) as a novel and safe treatment for Agit-AD with significant public health impact.


Alzheimer's disease (AD) is the most prevalent neurodegenerative disease of aging, affecting an estimated 5.2 million Americans and predicted to increase to 13.8 million by 2050. AD affects both cognition and emotion. Neuropsychiatric symptoms (NPS) in AD are a major cause of burden to patients, caregivers, and society and are near-universal at some point in the AD course with > 97% of AD patients having at least one symptom reported on the Neuropsychiatric Inventory (NPI).

One of the most troubling of these symptoms is agitation (Agit-AD), typified by a variety of problem behaviors including combativeness, yelling, pacing, lack of cooperation with care, insomnia, and restlessness. In community-based samples, Agit-AD is common. Agit-AD is associated with greater caregiver burden and shorter time to institutionalization, and there is a particularly acute need for interventions for severe Agit-AD in advanced dementia.

While there are currently no FDA approved medications for Agit-AD, psychotropic medications are widely prescribed "off-label" to treat Agit-AD. The most commonly used classes of medications prescribed for "off-label" treatment are antipsychotics and antidepressants. The evidence to date for efficacy remains mixed. Antipsychotics appear to have some degree of efficacy, but the effects are not highly replicable and their use is associated with increased mortality in elderly patients with dementia. Antidepressants (particularly selective serotonin reuptake inhibitors, (SSRI)s) appear to have fewer and less severe adverse effects compared to antipsychotics, as well as no known mortality risks, but are not without limitation. Therefore, exploration of alternative treatments for Agit-AD, particularly severe cases, is timely and warranted.

Dronabinol (Marinol) is FDA-approved for the treatment of anorexia/weight loss in AIDS and for nausea/emesis associated with chemotherapy, which is now being used off-label for Agit-AD. Dronabinol is a synthetic oral formulation of delta-9-tetrahydrocannabinol (THC), a psychoactive constituent of the cannabis plant that acts as a partial agonist at the Type 1 (CB1) and Type 2 (CB2) endocannabinoid receptors. This pharmacology is appropriate for targeting Agit-AD because CB1 receptor agonism can produce anxiolytic and antidepressant effects and CB2 receptor agonism can be anti-inflammatory.

The mechanism by which dronabinol exerts its effects on agitation and aggression in patients with dementia may occur through its action at the CB1 and/or the CB2 receptor. Agonists at the CB1 receptor in the brain improve anxiety and depression in humans as well as animal models. Dronabinol is an effective agonist at the CB1 receptor, which is generally specific to neurons and localized predominantly on the presynaptic terminal where it inhibits glutamatergic, dopaminergic and other neurotransmitter release. The CB1 receptor effects has been observed to mediate the observed anxiolytic and antidepressant effects of THC. Dronabinol is also an agonist at CB2, a potent anti-inflammatory receptor localized on activated microglia. Patients with AD have increased central and peripheral inflammation, likely as a result of the accumulation of beta-amyloid. Increased inflammation may have a number of behavioral effects that could drive the agitation and aggression in dementia patients. Dronabinol's effects at the CB2 receptor therefore could also produce changes in behavior in AD patients by reducing inflammation.

Condition Alzheimer's Disease
Treatment Placebo, Dronabinol (Marinol®)
Clinical Study IdentifierNCT02792257
SponsorJohns Hopkins University
Last Modified on4 October 2022


Yes No Not Sure

Inclusion Criteria

Diagnosis of Dementia due to AD
Presence of Agit-AD as defined by the provisional criteria from the International Psychogeriatric Association (IPA). The definition requires the presence of cognitive impairment, evidence of emotional distress, one of three observable types of behavior (excessive motor activity, verbal aggression, physical aggression), requires that the behavior cause excess disability, and notes that the behaviors cannot be solely attributable to another disorder such as psychiatric illness, medical illness, or effects of substance use
Clinically significant severity of agitation defined by NPI-C Agitation or NPI-C Aggression > 4\
Able to give informed consent, or deemed to lack such capacity by clinical team and legally authorized representative consents
Must be fluent in English and/or Spanish (includes reading, writing, and speech)
Must be admitted to clinical sites associated with McLean Hospital, Johns Hopkins University, and Miami Jewish Health Services as an inpatient/long term care resident during the study duration (3 weeks) OR be able to travel to these locations to enroll as an outpatient
Must be 60-95 years old
Must begin enrollment in study within one week of being determined eligible

Exclusion Criteria

Serious or unstable medical illness, including cardiovascular, hepatic, renal, respiratory, endocrine, neurologic or hematologic disease, which might confound assessment of safety outcomes
Seizure disorder
Baseline delirium as determined by Confusion Assessment Method (CAM) and Diagnostic and Statistical Manual of Mental Disorders (DSM) -5 criteria
Current use of lithium
Inability to swallow a pill
Clear my responses

How to participate?

Step 1 Connect with a study center
What happens next?
  • You can expect the study team to contact you via email or phone in the next few days.
  • Sign up as volunteer  to help accelerate the development of new treatments and to get notified about similar trials.

You are contacting

Investigator Avatar

Primary Contact


Additional screening procedures may be conducted by the study team before you can be confirmed eligible to participate.

Learn more

If you are confirmed eligible after full screening, you will be required to understand and sign the informed consent if you decide to enroll in the study. Once enrolled you may be asked to make scheduled visits over a period of time.

Learn more

Complete your scheduled study participation activities and then you are done. You may receive summary of study results if provided by the sponsor.

Learn more

Similar trials to consider


Browse trials for

Not finding what you're looking for?

Every year hundreds of thousands of volunteers step forward to participate in research. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.

Sign up as volunteer

user name

Added by • 



Reply by • Private

Lorem ipsum dolor sit amet consectetur, adipisicing elit. Ipsa vel nobis alias. Quae eveniet velit voluptate quo doloribus maxime et dicta in sequi, corporis quod. Ea, dolor eius? Dolore, vel!

  The passcode will expire in None.

No annotations made yet

Add a private note
  • abc Select a piece of text from the left.
  • Add notes visible only to you.
  • Send it to people through a passcode protected link.
Add a private note