Cannabis is usually associated with cognitive deficits such as short term memory loss, and problems maintaining attention. Research now suggests however that it may work differently on older users. Rather than invoking learning impairments, it may reverse age-related cognitive decline.
In a study, researchers demonstrated that cannabis was able to reverse aging in the brains of mice. To find this out, they treated mice aged between two, 12 and 18 months old with low doses of tetrahydrocannabinol (THC), the psychoactive ingredient in cannabis responsible for feeling ‘high’. They also monitored a control group on a placebo. After the four-week drug regimen, they then tested the learning capacities and memory performance of the mice including orientation skills and their ability to recognize other mice.
In the end, the mice dosed with THC demonstrated cognitive functioning similar to that of the two-month-old control animals. Meanwhile, the mice in the placebo group displayed memory loss and age-dependent decline in learning abilities appropriate for their age.
To explain the findings, Andreas Zimmer, one of the study’s authors, says, "With increasing age, the quantity of the cannabinoids naturally formed in the brain reduces...When the activity of the cannabinoid system declines, we find rapid ageing in the brain."
The researchers also examined the brain tissue and genetic activity of the mice treated with THC. In doing so, they found that the molecular signaling in these mice no longer resembled that of other mice their age. It was instead more similar to the younger mice. The researchers also observed an increase in nerve cells in their brains, something linked to learning and cognitive processing speed.
Although remarkable findings, as human trials assessing the same phenomenon are yet to be conducted, it is too soon to say whether the results translate over to humans. Nevertheless, the researchers say that their findings pave the way for further research avenues assessing the possibility of low doses of THC as a remedy for various brain injuries and treatment of age-related cognitive decline.