Association between stimulant and non-stimulant ADHD medications and completed suicide in adolescents and adults: A population-based nested case-control study

Introduction: ADHD has been linked to an increased risk of completed suicide. The aim of this study was to assess the relationship between ADHD medication use and completed suicide. Methods: This nested case-control study included individuals aged 12–49 in Quebec, Canada, diagnosed with ADHD and/or dispensed ADHD medication. Suicide cases (n = 472) between 2000 and 2021 were matched with 5 controls each (n = 2360) on date of birth, sex, and continuous public drug insurance coverage for at least 365 days before suicide death (index date). Multivariable conditional logistic regression was used to estimate the association between ADHD medication use and completed suicide. The association between specific ADHD medication types and completed suicide was also assessed. Results: After controlling for potential confounders, no significant association was found between ADHD medication use and completed suicide in the overall sample, in individuals aged 12–24 and 25 to 49 years, and those with a prior ADHD physician diagnosis. No significant differences were found when comparing the use of non-stimulants only (aOR 1.27; 95 % CI: 0.62, 2.63), stimulants and non-stimulants (aOR 1.01; 95 % CI: 0.33, 3.08), and ADHD consultation without medication (aOR 0.94; 95 % CI: 0.69, 1.28) against stimulant-only use. Conclusion: Both stimulants and non-stimulants were not associated with the risk of completed suicide. These findings can inform clinical decision-making.