Andreas Zimmer, lead author of the study and professor of psychology at Bonn University in Germany, says that the results of this research aids in understanding marijuana’s use as medicine. “Chronic, low-dose treatment with THC or cannabis extracts could be a potential strategy to slow down or even reverse cognitive decline in the elderly,” he stated in an article on DailyMail.co.uk. “THC treatment for 28 days restored the learning and memory performance of mature and old animals in the water maze, novel object recognition social recognition tests to the levels observed in young mice.”
For the study, Professor Zimmer and his team carried out three experiments. The team gave low doses of THC to mice at three different ages: two months, 12 months, and 18 months. In human age, this is roughly the equivalent to 20, 58, and 64-years old, respectively. Over the course of 28 days, the mice were subjected to three tests. In the first, mice had to learn how to navigate around a water maze. The second experiment had mice locate a specific object. The last test related to partner recognition. In all three tests, mature and old mice performed worse than the young group. However, when these groups were introduced to THC, the scientists found that their performance significantly improved. Researchers also noted a profound enhancement in memory and cognitive performance. Professor Zimmer published their findings in Nature Medicine and concluded with, “Cannabis preparations and THC are used for medicinal purposes. They have an excellent safety record and do not produce adverse side-effects when administered at a low dose to older individuals. Thus, chronic, low-dose treatment with THC or cannabis extracts could be a potential strategy to slow down or even to reverse cognitive decline in the elderly.”
Zameel Cader, an associate professor in clinical neurosciences at Oxford University commented on the study on NewsWeek.com and said the results of the study were “interesting.”
He was mentioned as saying, “first of all there’s clearly growing interest in the potential therapeutic role of cannabinoids, and in this particular case, THC on various human conditions. This paper is addressing a possible role for that compound in memory and cognition, which is relevant to disorders such as Alzheimer's and other dementias.” Professor Cader does caution the public not to jump to conclusions though; these findings are limited to animal models. Testing on humans, he said, would be problematic. “This is a challenge faced by anyone wanting to develop a therapy for a human disorder such as dementia. Human lifespan is very extensive. So the question would be, when would be the most appropriate time to give these kinds of medications? Over what period of time do you need to evaluate the effects? In humans it could be years before an effect is noticed.”
Professor Cader’s statement is reflective of the general medical community’s opinion regarding marijuana use. The issue here is the supposed adverse effects (especially in terms of addiction) marijuana can have. That being said, recent research indicates that cannabis use among older adults is rising. Data from the annual National Survey of Drug Use and Health (NSDUH) showed that from 2002-2014, the number of adults aged 50 to 64 who reported to have used cannabis more than tripled from 2.9 percent to nine percent.