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Study breakdown

Even Having Friends Who Use Substances Was Linked to Worse Mental Health in Teens

Cross SectionalStrong evidence
The takeaway

Among 167,504 screened adolescents, five distinct substance use patterns emerged, and all groups, including those who only reported friends' substance use, had higher rates of depression, suicidal ideation, and violence compared to non-using peers.

Pediatricians, school health programs, adolescent mental health clinicians, substance use prevention researchers.

Even teens who only reported friends' substance use had higher rates of depression and suicidal ideation

What the researchers found

Five latent classes of substance use were identified: friends' use only (37%), alcohol use (21%), polysubstance use (20%), cannabis use/some polysubstance use (18%), and other substance use (5%). All classes had higher prevalence of mental health problems and interpersonal violence compared to non-users, with the polysubstance use class showing the greatest differences.

Why it matters

The finding that even adolescents who only report friends' substance use (without personal use) show elevated mental health and violence risks suggests that substance-related screening should capture social context, not just individual behavior. The 17% prevalence of any substance use characteristic is also noteworthy.

The numbers in context

n=167,504 adolescents; 29,288 (17%) reported at least one substance use characteristic; 5 latent classes identified; cannabis/polysubstance class: 18%; outcomes: depressive symptoms, suicidal ideation, bullying, physical abuse, sexual violence, IPV.

How the study worked

Cross-sectional latent class analysis of 167,504 adolescents aged 13-17 screened during well-check visits in a large California healthcare system (2021-2022), examining four substance use behaviors (past-year alcohol, cannabis, other substances, friends' use) and associations with mental health and violence outcomes.

What this study cannot tell us

Cross-sectional design cannot determine temporal direction. Screening during well-check visits may miss adolescents who do not attend regular healthcare. Self-reported substance use may underestimate actual use. California-specific healthcare system may not represent other regions. Latent class analysis identifies patterns but does not explain causation.

How to read the evidence

Strong: Very large sample (167,504) from a real-world healthcare system with comprehensive screening for multiple behavioral health outcomes.

When this study was published

Published in 2025 with 2021-2022 screening data.

The bigger picture

This study supports the growing movement toward comprehensive behavioral health screening during routine adolescent healthcare visits. By showing that substance use patterns are closely intertwined with mental health and violence, it argues against addressing these issues in isolation.

Questions still open

  • Why do adolescents with only friends' substance use show elevated mental health risks? Does peer substance use predict future personal use? Would integrated screening and intervention for substance use, mental health, and violence be more effective than separate programs?

Common questions

Why does having friends who use substances matter?
In this study, adolescents who only reported friends' substance use (without personal use) still had elevated mental health and violence risks. This could reflect shared risk environments, social stress, or early-stage influence that precedes personal substance use.
What is latent class analysis?
Latent class analysis is a statistical method that identifies hidden groups (classes) of individuals who share similar patterns. In this study, it identified five distinct groups of adolescents based on their substance use behaviors, revealing that cannabis users often also used other substances.

Read the original research

Patterns of substance use and associations with mental health and interpersonal violence among adolescents.

Addictive behaviors reports, 21, 100597

Citation

Ogden, Shannon N; Cortez, Catherine; Sterling, Stacy A; Alexeeff, Stacey E; Slama, Natalie E; Campbell, Cynthia I; Satre, Derek D; Asyyed, Asma H; Does, Monique B; Altschuler, Andrea; Lu, Yun; Young-Wolff, Kelly C. (2025). Patterns of substance use and associations with mental health and interpersonal violence among adolescents.. Addictive behaviors reports, 21, 100597. https://doi.org/10.1016/j.abrep.2025.100597

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