Doctors who prescribe medical cannabis – and the health authorities who approved its sale to the public – have been concerned that it may affection the cognitive functioning including concentration, psychomotor reaction, memory and learning abilities of older patients who use it.
Researchers at the University of Haifa’s School of Public Health investigated this matter and found that medical cannabis does not impair the mental function of its older users.
Patients treated with medical cannabis for the treatment of chronic pain are no different from patients on other medications,” said Dr. Sharon Sznitman and Dr. Galit Weinstein, who headed the study. In the US, people over
60 represent approximately 20% of medical cannabis users, while in Israel, a quarter of legal users are aged 65 years or older.
“More and more adults have been using cannabis in recent years to relieve pain. Our research is the first step in a more accurate assessment of the risk versus benefit of cannabis treatment in this population,” they said.
Chronic pain affects between a fifth and almost two-fifths of the adult population in the world, and many patients and caregivers hope to cope with these pains using medical cannabis. According to the researchers, most studies carried out so far have examined the effect of cannabis use on cognitive function in young people. “It has been known from previous studies that medical cannabis can have long-term effects on the brain when consumed at a young age, but this is not necessarily the same effect when used by the elderly,” the researchers explained.
In the new study published in the journal Drug and Alcohol Review under the title Medical cannabis and cognitive performance in middle to old adults treated for chronic pain,”
Sznitman and Weinstein, together with Dr. Simon Wolfson from Rambam Medical Center and Prof. David Meiri from the Technion-Israel Institute of Technology in Haifa decided to examine the effect of cannabis on cognitive function in older people suffering from chronic pain.
The study involved 125 subjects who suffered from chronic pain, of whom 63 had Health Ministry licenses for the use of medical cannabis and 62 did not. Patients who had been diagnosed with Parkinson’s disease, anxiety or serious mental illness, post-traumatic stress disorder, clinical dementia, multiple sclerosis, a brain tumor, traumatic brain injury,
stroke and cancer patients who received chemotherapy were not included in the study. The mean age of the subjects was 62 years.
Cognitive function is tested through a series of computerized tests that evaluate the functioning of psychomotor responses, concentration, memory and learning abilities.
Participants were asked to refrain from using cannabis three hours before undergoing tests of their cognitive abilities so that they were not under the immediate influence of the drug.
The results of the study show that there are no significant differences in cognitive function between older people who suffer from chronic pain and use medical cannabis and people who suffer from pain to the same extent and do not use medical cannabis. “Although cannabis patients had used it consistently for at least a year, we have not found that their brain function is lower than that of people similar to them in age and background diseases,” the team said.
“Our findings may minimize concerns among physicians dealing with chronic pain and among patients suffering from it regarding the possible effects of cannabis on brain function. But further research should be conducted to substantiate the results of the present study,” the researchers concluded