Exploring the Link Between Cannabis Use and Subjective Cognitive Decline in Middle-aged and Older Adults


Subjective Cognitive Decline (SCD) has emerged as a significant concern among middle-aged and older adults, with increasing research focusing on its potential relationship with cannabis use. In this article, we delve into the complexities of this association, considering factors such as frequency, method of use, and underlying reasons for cannabis consumption.

The United States (U.S.) Centers for Disease Control and Prevention (CDC) estimates that a considerable percentage of adults in the 45 and older age group experience SCD, which often precedes cognitive impairment and dementia. Research indicates that individuals reporting SCD are at a significantly higher risk of developing dementia.

Over the past decade, cannabis use has seen a notable surge in legalization and acceptance, particularly for medical purposes. This trend has extended to older adults, with a visible increase in cannabis use among those aged 55 years and older. Understanding the impact of cannabis on cognitive function, memory, and decision-making is paramount, given its widespread usage.

Numerous studies have explored the association between cannabis consumption and cognitive function. Longitudinal cohort studies and analyses of national survey data have provided insights into the potential effects of cannabis on verbal recall, cognitive performance, and subjective memory complaints. However, the threshold for considering these effects as indicative of dementia remains a point of discussion, as indicated by the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5).

While past research has primarily focused on the frequency of cannabis use, our study takes a comprehensive approach. We delve into not just how often cannabis is consumed but also the reasons behind its use and the methods of administration. Cannabis comprises various cannabinoids, notably tetrahydrocannabinol (THC) and cannabidiol (CBD), each with distinct effects. The purpose for which cannabis is used, whether for recreational or medicinal purposes, can influence its cognitive impact.

Moreover, the method of cannabis administration, such as smoking, vaping, or edibles, can also play a role in its cognitive effects. Despite these nuances, limited research has explored how these factors intersect with SCD, presenting a critical knowledge gap that our study aims to address.

By comprehensively examining the interplay between reason, frequency, and method of cannabis use with SCD among middle-aged and older adults in the U.S., our research contributes to a nuanced understanding of this complex relationship. This understanding is vital for informing public health policies, clinical practices, and individual decision-making regarding cannabis use in older populations.

Sample Characteristics

The study utilized survey sampling weights for the Behavioral Risk Factor Surveillance System (BRFSS) data, representing 4,744 respondents estimated to represent 563,339 U.S. adults aged 45 years and older. Among them, approximately 10.9% reported experiencing Subjective Cognitive Decline (SCD). The largest proportion of individuals fell into the 60-64 age group, comprising 15.8% of the sample. The sample was predominantly female (52.7%), with 46.2% self-identifying as Asian, 26.5% White, 5.9% Hispanic, and 1.5% Black. Most respondents were college graduates (34.9%) residing in metropolitan counties (78.1%). Regarding health, a significant portion reported very good health (33.9%), with diabetes being the most prevalent health condition (15.4%). On average, respondents experienced poor mental health for 2.8 days within the last 30 days. Substance use data showed that 42.8% consumed alcohol in the past 30 days, while 60.7% had never smoked.

About 7.5% of the respondents were cannabis users, with 3.2% using it for medical purposes, 2.1% for non-medical reasons, and approximately 2.2% for both medical and non-medical reasons. The data included five methods of cannabis use, with smoking being the most common (5.4%), followed by eating (1.2%), drinking (0.2%), vaporizing (0.3%), and dabbing (0.3%). The weighted average of cannabis use in the past 30 days was approximately 1.4 days.

Bivariate Tests

Statistically significant associations were found between reasons for cannabis use and SCD in a weighted chi-square test (p<.001). SCD was more prevalent among those using cannabis for medical (8.7%) and combined medical and non-medical reasons (4.5%) compared to non-medical users (0.5%).

Weighted t-tests revealed a significant association between cannabis use frequency and SCD (p<.01). Those with SCD had a significantly higher average of cannabis consumption days compared to those without SCD.

A significant association was also observed between the method of cannabis use and SCD (p<.001). Generally, SCD was more common among cannabis users, particularly smokers, with a higher prevalence of SCD compared to non-users.

Multiple Logistic Regression

Multiple logistic regression analysis confirmed a significant association between cannabis use reason and SCD across all models. Non-medical cannabis use was associated with significantly decreased odds of SCD (aOR=0.04, 95% CI=0.01-0.44, p<.05) after adjusting for covariates. However, medical use and combined medical and non-medical use showed lower odds of SCD but were not statistically significant.

Cannabis consumption frequency showed a slight positive association with SCD but was not significant. Similarly, all methods of cannabis use were associated with increased odds of SCD, with smoking showing the highest odds, although not statistically significant.

Among covariates, education level, general health, history of heart disease, history of depression, and days of poor mental health were significantly associated with SCD. For example, respondents with a college education had decreased odds of SCD, while those with excellent general health had lower odds of SCD. Conversely, a history of heart disease or depression increased the odds of SCD.

No significant associations were found between SCD and other substance use behaviors, such as alcohol and cigarette smoking.


This study delves into the intricate relationship between various aspects of cannabis use – encompassing reasons, frequency, and methods of administration – and Subjective Cognitive Decline (SCD) in a national U.S. sample of middle-aged and older adults. The findings reveal a significant association between non-medical cannabis use and reduced odds of SCD compared to non-users. Several factors could contribute to this observation.

Non-medical cannabis often contains tetrahydrocannabinol (THC), a psychoactive component responsible for the “high” sensation, whereas cannabidiol (CBD) is non-psychoactive and commonly used for anxiety and chronic pain management. Interestingly, a mouse study in 2017 suggested that very low doses of THC might improve cognitive impairment among older female mice, although the applicability to humans requires further investigation.

Insomnia is a commonly reported reason for cannabis use, and its efficacy in alleviating sleep disturbances, particularly when related to factors like nightmares and PTSD, has been debated. Some studies associate non-medical THC use with decreased insomnia and improved sleep quality, which could contribute to the observed decrease in SCD.

Stress reduction is another motivation for cannabis use, with CBD known to effectively reduce stress. Elevated stress levels are linked to reduced cognitive function among older adults, further highlighting the potential cognitive benefits of cannabis use.

Although bivariate tests suggested a positive association between cannabis use frequency and SCD, this association was not significant after adjusting for reasons, methods of use, and other covariates in regression models. While heavier cannabis use is generally associated with cognitive impairment, its impact may vary across age groups, with younger populations potentially experiencing more pronounced effects than older adults.

The study’s findings regarding different methods of cannabis use and their association with SCD did not show significant differences. This contrasts with prior research primarily focusing on smoking as the main method of cannabis use. However, it’s crucial to consider that smoking cannabis leads to more immediate effects due to rapid absorption through the lungs, whereas other methods like edibles or beverages have a delayed onset.

The study also highlights significant associations between education level, general health, mental health, history of heart disease, and history of depression with SCD. These findings align with previous research, emphasizing the multifaceted nature of cognitive decline risk factors.

Early diagnosis and intervention for conditions like dementia are critical for effective management. SCD serves as a crucial precursor to dementia, emphasizing the importance of early detection and intervention strategies. Public health initiatives aimed at increasing awareness and encouraging medical consultation for SCD can facilitate timely interventions and lifestyle adaptations.

Despite the advancements in understanding cognitive decline, several limitations exist in this study. The analysis did not consider geographical variations in cannabis regulations, potentially introducing bias. Self-reported data on cannabis use and SCD may also be subject to reporting bias. Additionally, the study focused on adults aged 45 and older, warranting further research on younger populations and more objective measures of cognitive impairment.

Nevertheless, the study’s strengths lie in its use of a national dataset with sampling weights, enhancing the generalizability of findings. It also comprehensively explores different facets of cannabis use, providing valuable insights into the complex relationship with SCD. Further research is warranted to elucidate the mechanisms underlying these associations and inform targeted interventions for cognitive health in aging populations.

reference link : https://www.eurekaselect.com/article/138726


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