In recent years, the intersection between physical exercise and its effects on substance use disorders has garnered significant interest within the scientific community. A new study delves into this relationship, exploring how regular physical activity might influence the severity of dependence among individuals who use illicit substances.
The research, published in the Journal of Psychoactive Drugs, provides evidence that engaging in frequent exercise may be associated with lower levels of dependency on various drugs.
Substance use disorders represent a significant challenge to public health systems worldwide, characterized by high rates of relapse post-treatment. Traditional approaches to addiction treatment have often focused on psychological and pharmacological interventions, yet emerging evidence suggests that supplementary strategies, such as exercise, could offer additional benefits.
The rationale behind this study is rooted in the complex interplay between physical activity and the brain’s reward system. Various forms of exercise, including aerobic and resistance training, are known to impact the same neural pathways and receptors influenced by psychoactive substances. This shared mechanism suggests that exercise could offer a natural, alternative means to modulate the brain’s reward system, potentially reducing the appeal of drug use by enhancing overall mental and physical well-being.
“My interest in this topic stemmed from my undergraduate studies in psychology, where I found myself fascinated by substance use behaviors (since everything around it had been kind of a taboo when I was younger) and later I also got very fascinated by the beneficial impact of exercise on mental health,” said study author Baldur Jón Gústafsson of Middlesex University.
“When selecting a topic for my master’s thesis, I had discovered that both exercise and substance use influence similar neurotransmitters and brain receptors. This led me to hypothesize that individuals with multiple ways for activating these mechanisms, might exhibit lower dependency compared to those with only one outlet.
“With the generous assistance of Adam Winstock, the founder of The Global Drug Survey, I gained access to invaluable data to explore this hypothesis. As well as the guidance of esteemed scholars he connected me with, who played a big role in getting this published later on.”
The Global Drug Survey is a comprehensive, anonymous online questionnaire designed to gather detailed information on drug use patterns globally. For their new study, Gustafsson and his colleagues targeted a specific cohort of individuals who reported using at least one of nine designated illicit substances within the past year and provided complete responses to questions assessing their exercise habits and levels of dependency through the Severity of Dependence Scale (SDS).
The sample for this analysis included 57,110 participants who met the criteria for inclusion by having engaged with one of the specified substances and completed all relevant sections of the survey. The substances in question spanned a range including cannabis, MDMA, cocaine, amphetamines (both powder and paste forms), methamphetamine, ketamine, GHB, and mephedrone. Participants were also queried about their exercise frequency over the previous year, with responses categorized into three levels: none or low, moderate, and high.
The researchers found that for a majority of the substances investigated, including cannabis, MDMA, cocaine, and methamphetamine, individuals who reported higher frequencies of exercise tended to have lower SDS scores. This suggests that engaging in regular physical activity may be associated with less severe forms of dependency among users of these substances.
“While further research is needed, preliminary findings suggest that regular exercise could potentially assist individuals in reducing substance use dependency or even mitigate the likelihood of developing dependency among new users,” Gústafsson told PsyPost.
Among the various substances analyzed, cannabis stood out due to its widespread use and the significant inverse relationship observed between exercise frequency and the SDS scores. Specifically, the data revealed that individuals who reported engaging in moderate to high levels of exercise exhibited lower SDS scores for cannabis use.
This finding aligns with theoretical perspectives suggesting that exercise can modulate the brain’s reward system, impacting the release and reuptake of neurotransmitters involved in pleasure and addiction.
“It was interesting to see the strongest connection with cannabis, given the striking similarity between its active psychoactive compounds—like THC and CBD—and our own endocannabinoids,” Gústafsson explained. “They effortlessly bind to our cannabinoid receptors, like a key into a lock.”
“In contrast, stimulants for example, exert their effects on us more indirectly, by affecting the release or recycling of neurotransmitters already present. Conducting a similar study in the future, with opiates as well, could be very interesting, as they, like cannabinoids, directly interact with opiate receptors.”
However, the study’s findings also nuanced the relationship between exercise and substance dependency. For certain substances, such as ketamine, GHB, and mephedrone, the analysis did not reveal a significant impact of exercise frequency on SDS scores. This suggests that the protective effects of exercise against substance dependency may vary depending on the specific drug in question, as well as possibly on the patterns of use and individual user characteristics.
Moreover, the study differentiated between participants who exclusively used one of the nine substances and those who reported polydrug use. This distinction shed light on the complex dynamics of substance use and the potential moderating role of exercise. Among those who used only one drug, the protective effect of exercise appeared more consistently across different substances.
Despite these promising insights, the study is not without limitations. The cross-sectional design precludes definitive conclusions about causality, and the reliance on self-reported data may introduce biases.
“The sample utilized is not based on probability sampling,” Gústafsson said. “Nevertheless, employing non-probability sampling methods, such as anonymous online surveys like the Global Drug Survey, proves to be a pragmatic and efficient approach for gathering data on stigmatized behaviors within difficult-to-access demographics, such as illicit substance users.”
The study, “Sweating for Sobriety: Exploring the Relationship Between Exercise Engagement and Substance Use Disorders,” was authored by Baldur Jón Gústafsson, Cheneal Puljević, Emma L Davies, Monica J. Barratt, Jason Ferris, Adam Winstock, and Timothy Piatkowski.
