New research out of Israel shows marijuana can help improve symptoms of Alzheimer's disease. A low dose of the cannabinoid found in marijuana, tetrahydrocannabinol (THC), was found to show significant improvements of several behavioral domains related to the neuropsychiatric symptoms associated with Alzheimer's disease dementia.

The goal of the study was to measure both efficacy and safety related to the consumption of a medical cannabis oil containing THC. Assaf Shelef, M.D., from Abarbanel Mental Health Center and Sackler Faculty of Medicine at Tel-Aviv University, led the team reporting the improvement in behaviors related to dementia.

The study was limited in that only 10 subjects were included in the four-week prospective trial. However, the subjects did report significant decreases in delusions, aggression, agitation, irritability, apathy and sleep problems. Furthermore, the caregivers reported less personal distress during the treatment of the participants with Alzheimer's disease.

The research group concluded that the use of medical cannabis oil is safe and shows promise as a treatment option.

Another team led by Geke A.H. van den Elsen, M.D., from the Departments of Geriatric Medicine/Radboudumc Alzheimer Centre in the Netherlands, also reported the use of a low dose of THC in a medical oil to be safe. They studied 24 patients with dementia using the THC oil and another 26 patients with dementia who received a placebo.

The researchers found the symptoms were reduced in both groups, but the differences between the groups were not significantly different. The side effects were also not significantly different between the groups. The conclusion was that the THC oil was safe at those doses, clearing concerns for further testing at higher doses.

Earlier studies demonstrated that cannabinoids were effecting in treating structural indications of Alzheimer's disease. THC has been shown to slow down the clumping of the amyloid proteins that contribute to Alzheimer's disease. Studies using low concentrations of THC on cell models show that not only does THC inhibit clumping, but also enhances positive aspects of the cell functions.

THC appears to have therapeutic potential through multiple functions and pathways within the body. However, the reports of improving neuropsychiatric symptoms have been sparse.

A literature review concluded there is evidence supporting the use of synthetic cannabinoids for the treatment of dementia. However, definitive conclusions cannot be made in general for cannabinoids — including THC — as the studies are often limited by small sample size, short trial duration and a lack of placebo controls in some studies.

Further study is certainly warranted.