11-23-2024 8:04am

Cannabis has No Significant Harmful Effects’ On Age-Related Cognitive Decline, Study Shows

Chris Edwards Editor

Per a recent study, since the 1960s, cannabis use has been rapidly increasing, especially among younger people, reaching its peak in the late 1970s (World Health Organization Committee on the Health Effects of Marijuana: An Evidence Review and Research Agenda, Board on Population Health and Public Health Practice, Health and Medicine Division, National Academies of Sciences, Engineering, and Medicine. Cannabis is currently classified under Schedule I of drugs by the United States Drug Enforcement Administration, which is a list including drugs with no currently accepted medical use and a high potential for abuse. Recreational use of cannabis is illegal in Denmark; however, according to a recent report from the Danish Health Authority, 9.7% of the Danish population aged 16–44 use cannabis annually. Given the high prevalence of cannabis use, its potential association with cognitive decline could have significant implications for public health. While there is substantial evidence of the short-term negative effects of cannabis use on cognition and cognitive development, its link to age-related cognitive decline has been sparsely studied and has shown mixed resultsIn new study with a population that consisted of 5162 men who had participated in Danish follow-up studies on cognitive aging. These studies included scores on the military intelligence test Børge Prien's Prøve from both the conscription assessment (mean age = 20 years; p1 and p99: 18 and 26 years) and from the follow-up (mean age = 64 years; p1 and p99: 55 and 72 years) as well as extensive data on lifestyle and health from the follow-up questionnaires. The association between cannabis use and age-related cognitive decline was investigated in linear regression models.

The Results

Men with a history of cannabis use had less cognitive decline from early adulthood to late midlife compared to men without a history of cannabis use. Among cannabis users, neither age of initiation of cannabis use nor frequent use was significantly associated with a greater age-related cognitive decline.

The Discussion and Conclusions

In a sample of more than 5000 men followed for a mean of 44 years, we found no significant harmful effects of cannabis use on age-related cognitive decline. This study contributes to the sparse knowledge on this subject and aligns with most existing studies, suggesting no association between cannabis use and greater cognitive decline. More specifically, in the present study, cannabis users experienced slightly less cognitive decline compared to nonusers, and the association remained significant when controlling for potential confounders. Among cannabis users, no significant association was found with cognitive decline for either age of initiation of cannabis use or frequent cannabis use. Further studies are needed to investigate whether these findings reflect that there are no adverse effects on cognitive decline or that the effects of cannabis are temporary and disappear after a prolonged period of time.