The complex relationship between marijuana use and brain health has taken centre stage in a recent study published in JAMA Neurology. Canadian researchers have been exploring the marijuana dementia risk and its potential long-term effects. Their findings are alarming. Individuals requiring acute hospital care due to marijuana use appear to face an elevated risk. Within five years, they are more likely to develop dementia compared to the general population.

This unprecedented discovery shines a spotlight on the rapidly evolving understanding of cannabis and its effects, particularly on older adults.

Cannabis dementia link explored

The study, conducted in Ontario, Canada, analysed a massive dataset of 6,086,794 individuals aged 45 and above who had no prior diagnosis of dementia. Out of this group, researchers identified 16,275 individuals who visited an emergency department or were hospitalised.

The results? Researchers found that individuals with marijuana-related acute care visits face a staggering 1.7 times greater likelihood of developing dementia. This diagnosis is more likely to occur within five years compared to the general population.

The implications of this research eloquently echo a critical message about monitoring cannabis use and its long-term implications, particularly for older adults whose brains may already be more vulnerable to age-related changes.

Scrutinising the rise in acute care incidents

The study highlights a notable rise in acute care incidents connected to marijuana use over time. Between 2008 and 2021, annual rates of marijuana-related emergency visits spiked impressively by fivefold among individuals aged 45 to 64. However, researchers observed the most dramatic trend among those aged 65 or older, as their rate shot up by a staggering 26.7-fold.

This increase aligns closely with key developments in cannabis policy in Canada. The liberalisation of medical cannabis in 2014 and the Canadian government’s eventual legalisation of recreational cannabis in 2018 marked a turning point in marijuana accessibility and use within the population.

While these legislative changes broadened access, they also highlight a pressing need to better understand the role of cannabis on health, particularly in older demographics.

How marijuana may influence dementia risk

The study stops short of drawing a direct causal relationship between marijuana use and dementia. However, it opens an important dialogue. Researchers explained that cannabis use might alter brain structure and cognitive functions. These changes could potentially heighten the risk of dementia.

But that’s not all. Researchers have also linked marijuana to other well-known contributors to dementia risk, including:

• Reduced educational attainment – Chronic cannabis use is known to negatively impact academic achievements, a factor associated with dementia risk.
• Greater likelihood of hypertension – High blood pressure, or hypertension, is considered a significant risk factor for vascular dementia.
• Higher risk of trauma –Cannabis use, notably through its role in motor vehicle collisions, indirectly increases head trauma incidents and links them to cognitive decline.
• Social isolation and depression – Mental health and social relationships profoundly influence brain health. Cannabis users may face a greater risk of experiencing depressive episodes or withdrawing socially, both of which increase dementia risk over time.

Why age adds complexity to cannabis use

Older adults often face compounding vulnerabilities, including existing health conditions, that may exacerbate the effects of cannabis use on their cognition. With natural ageing already impacting memory, attention, and reasoning abilities, any additional stressors on the brain, like those posed by cannabis, could amplify risk factors for dementia.

The researchers highlighted that much of the growth in cannabis-related acute care started in 2015, following changes in policy, reinforcing the need to focus on how societal changes shape usage trends.

A wake-up call for monitoring brain health

With marijuana becoming increasingly accessible and accepted, this study highlights the need for vigilance in understanding its potential risks. For public health professionals and caregivers, it underscores the importance of staying critically aware of the challenges older adults face and implementing strategies to protect brain health.

The potential link between cannabis use and dementia, especially for those requiring hospital-based care, serves as a sobering reminder to approach the evolving cannabis landscape with caution. Monitoring usage patterns, particularly among older and vulnerable populations, could play a key role in mitigating the risks of cannabis-induced cognitive impairments. Read more