Loyola researchers find psychedelic use linked to lower overdose, relapse risks

Using national electronic health record data from more than 3 million patients, a team of researchers from Loyola University Chicago’s Parkinson School of Health Sciences and Public Health discovered that individuals with substance use disorders who had documented psychedelic exposure experienced substantially fewer overdoses, relapses, and psychiatric emergencies compared with similar patients who had not used psychedelics.  

In the recently published study, researchers observed reduced risks across different types of substance use and persisted after accounting for age, sex, and co-occurring conditions.  

Problem and significance

Substance use disorders are a major public health crisis, contributing to rising overdose and mental health emergencies across the United States. Despite ongoing efforts, many patients continue to relapse or experience severe adverse outcomes even while receiving care.  

Psychedelic and anesthetic compounds have gained renewed attention as potential therapeutic tools, yet large-scale evidence from real-world clinical data has been scarce. These findings highlight the potential of large-scale, real-world data to uncover patterns that might otherwise remain hidden in smaller clinical studies. 

“Our findings expand the scientific conversation beyond traditional treatment models and suggest that both psychedelics and anesthetics may have underrecognized protective roles worth exploring in future research,” said lead researcher Fares Qeadan, associate professor of biostatistics in Parkinson. 

Three key takeaways

1. Novel discovery: The study uncovered a previously unreported protective association between anesthetic exposure and reduced all-drug overdose risk; a finding that opens new lines of inquiry into potential neurobiological or care-related mechanisms.  
2. Consistent protective trends: Across substance use categories, psychedelic exposure was linked to lower overdose and relapse rates, even after adjusting for demographics and comorbidities.  
3. Path forward for clinical research: The findings underscore the need for controlled trials to understand mechanisms, optimize safety, and determine how psychedelic- and anesthetic-assisted therapies could be responsibly introduced into mainstream addiction treatment. 

Using the findings

The study is one of the first large-scale, real-world analyses of psychedelics in clinical populations and provides new evidence that these compounds may have therapeutic potential when used safely and in appropriate medical contexts. The findings lay the groundwork for future studies exploring how psychedelic-assisted therapies could be integrated into addiction and mental-health treatment. 

“One of the most surprising discoveries was that anesthetic exposure, such as medications used in outpatient procedures, was linked to a lower risk of all-drug overdose among patients with substance use disorders,” Qeadan said. “This protective association was not part of our initial hypothesis and represents a novel finding that warrants deeper investigation. It suggests that physiological or behavioral factors surrounding anesthetic use may play a previously unrecognized role in stabilizing high-risk patients. For our team, this unexpected result underscored how large-scale real-world data can reveal new, actionable insights about addiction and recovery pathways sometimes in places we least expect to find them.” 

Read more stories from the Parkinson School of Health Sciences and Public Health.

Contact the researcher:

Fares Qeadan
Associate Professor of Biostatistics
fqeadan@luc.edu