Using the Diffusion of Innovation Theory to explain the declining trend in adolescent drunkenness between 2002 and 2022 across 46 countries

INTRODUCTION: Using Diffusion of Innovations Theory, we investigated whether countries with higher innovation capacity showed earlier tipping points (shift from increasing to decreasing drunkenness) and steeper declines in adolescent drunkenness (2002-2022). Innovation capacity likely facilitates these shifts through knowledge generation, policy implementation, and norm diffusion. METHODS: Trends in adolescent drunkenness were examined across 46 countries using six cross-sectional school-based survey waves from the international HBSC study (N = 319,843 15-year-olds). Data were complemented by country-level innovation capacity, per capita GDP, and Gini-coefficients. Two-level random effects models tested cross-level interactions between innovation capacity and linear and quadratic time trends in adolescent drunkenness frequency. RESULTS: Significant small-to-moderate cross-level interactions were found. Countries with high innovation capacity showed immediate linear declines (B = -.217, SE = .083), that flattened or showed an upward shift by 2022 (B = .031, SE = .007). Countries with low innovation capacity displayed an inverted U-shape trend in the early 2000s with a later tipping point (B = -.006, SE = .002). A steeper linear decline was observed for countries with higher (vs. lower) innovation capacity from their respective tipping point onward (B = -.273, SE = .083). DISCUSSION: Innovation capacity may accelerate adoption and diffusion of healthier behaviors through more rapid translation of health evidence into effective policy, parenting, and norms. While countries with high innovation capacity showed earlier declines, their initially higher levels of drunkenness may have created greater urgency for action. Earlier peaks and subsequent faster reductions in future alcohol-related health care needs are expected in these countries, though the possible recent trend reversal warrants close monitoring.