Cannabinoids for Behavioural Symptoms in Adults with Dementia: A Review of Clinical Effectiveness and Guidelines

Key Message

A total of four publications met the inclusion criteria: two systematic reviews and two randomized cross-over trials. No evidence-based guidelines were identified. The systematic reviews collectively included eight unique studies, which primarily studied treatment with dronabinol. Nabilone treatment was limited to a single case report. Interpretation of the findings presented narratively by the systematic reviews is hampered by sparse reporting. In particular, it is difficult to discern much about the patient population studied due to a lack of reporting detail about patient characteristics, including age, sex, severity of dementia, co-morbidities, concomitant medications, and setting (i.e., community versus long-term care). Although the studies of dronabinol treatment are consistent in reporting a reduction in behavioural symptoms, the exposure to treatment tended to be short, and almost half of the studies had no comparator. Moreover, adverse event reporting was limited to three of the eight studies, further complicating risk-benefit determinations. The two randomized cross-over trials, despite better reporting, contribute little to the evidentiary base as they were small, exploratory safety sub-studies of short-term treatment exposure to a formulation of THC unavailable in Canada. Thus, there remains a gap in the evidence on the use of cannabinoids in the treatment of dementia, which currently makes evidence-informed decision-making challenging.