Individual- and school-level patterns of substance use and mental health symptoms in a population-based sample of secondary students: A multilevel latent profile analysis.

Background: While substance use and mental health symptoms commonly co-occur among adolescents, few population-level studies have examined profiles of co-occurrence to inform tailored prevention and early interventions.

Methods: A multilevel latent profile analysis was conducted on a representative sample of 11,994 students in 68 secondary schools to: 1) identify distinct profiles of co-occurring substance use and mental health symptoms; 2) identify types of schools based on student profiles; and 3) explore school correlates of student profiles and school types, including school climate, belonging, and safety.

Results: Five student profiles and three school types were identified. Among students, 57.6 % were in a low substance use and mental health profile, 22.5 % were in a high mental health but low substance use profile, 9.7 % were in a heavy drinking and cannabis use profile, 3.7 % were in a heavy drinking and smoking profile, and 6.5 % were in a high substance use and mental health profile. Positive school climate, belonging, and safety increased the odds of students being in the low profile, with belonging yielding larger effects among females. Among schools, 28 % had low, 57 % had moderate, and 15 % had high levels of student substance use and comorbid mental health symptoms. Rural schools were disproportionately represented in higher risk school types.

Conclusions: The identified student substance use and mental health symptom profiles can serve as targets for tailored prevention and early interventions. Results support examining school-based interventions targeting school climate, belonging, and safety with potential benefits to both substance use and mental health.