College students across seven countries fell into three substance use classes, with polysubstance users showing higher impulsivity and childhood adversity | Research

The takeaway

Across 9,065 college students in seven countries, those in the heaviest polysubstance use class had more adverse childhood experiences, greater impulsivity, and more ruminative thinking than those who primarily drank alcohol or co-used alcohol with cannabis.

University health services, prevention researchers, global substance use epidemiologists

9,065 students across 7 countries; polysubstance users had the highest adverse childhood experiences

What the researchers found

Three substance use classes emerged: polysubstance users, alcohol-marijuana-tobacco co-users, and primarily drinkers. Polysubstance users had significantly higher adverse childhood experiences, more ruminative thinking, and greater impulsivity than the other classes. Country-level comparisons showed the US was most similar to Spain, Argentina, and Uruguay in alcohol-marijuana-tobacco co-use.

Why it matters

Identifying which college students are at highest risk for polysubstance use and what psychological factors distinguish them can help universities target prevention programs more effectively, especially since these vulnerability factors are potentially modifiable.

The numbers in context

9,065 students across 7 countries; 71% women. Three classes identified via latent class analysis. Class 1 (polysubstance users) had greater adverse childhood experiences, higher rumination, and more impulsivity than Classes 2 and 3.

How the study worked

Latent class analysis of an online survey of 9,065 college students (71% women) from the US, Canada, South Africa, Spain, Argentina, England, and Uruguay. Classes were derived from lifetime use of multiple substances. Between-class differences in adverse childhood experiences, ruminative thinking, and impulsivity-like traits were tested.

What this study cannot tell us

Convenience sampling. Lifetime use measure does not capture current patterns or frequency. Cross-sectional design. Self-reported data. The 71% female sample may not represent all college populations.

How to read the evidence

Large multi-country sample with latent class analysis, but convenience sampling and cross-sectional design limit causal interpretation.

When this study was published

2026 publication

The bigger picture

Polysubstance use among college students is not just about access or culture. The finding that childhood adversity and psychological traits differentiate use patterns suggests that early intervention for trauma and emotion regulation could prevent escalation.

Questions still open

Could interventions targeting rumination and impulsivity reduce polysubstance use in this population? Why do country-level patterns differ, and what cultural factors drive these differences?

Common questions

What does "polysubstance use" mean here?

Using multiple substances during one's lifetime, including combinations of alcohol, cannabis, tobacco, and other drugs. The most complex class used the widest range of substances.

Were patterns the same across countries?

No. The US was more similar to Spain, Argentina, and Uruguay in alcohol-marijuana-tobacco co-use, and more similar to South Africa in broader polysubstance use patterns.

Read the original research

A Latent Class Analysis of Polysubstance Use Patterns and Their Association with Ruminative Thinking Styles, Impulsivity-Like Traits, and Adverse Childhood Experiences Among College Students from Seven Countries.

Substance use & misuse, 61(4), 598-608

View on PubMed ↗Publisher’s paper ↗

Citation

Michelini, Yanina; Luque, Maribel; Folivi, Folly; Pilatti, Angelina; Bravo, Adrian J. (2026). A Latent Class Analysis of Polysubstance Use Patterns and Their Association with Ruminative Thinking Styles, Impulsivity-Like Traits, and Adverse Childhood Experiences Among College Students from Seven Countries.. Substance use & misuse, 61(4), 598-608. https://doi.org/10.1080/10826084.2025.2568944