Adolescent alcohol consumption has been in decline across many high-income countries since the early to mid-2000s. This is a significant public health trend, with few documented examples from history where such a global downward shift in alcohol consumption has occurred primarily among the adolescent segment of the population. In this commentary we describe the nature and breadth of the trend; reflect on the environmental, social and policy factors that have been proffered; and argue that to adequately understand and support the maintenance of these trends, three important methodological considerations are needed for future research. Firstly, longitudinal panel and qualitative studies are needed to complement and inform continuing cross-sectional research. Secondly, a collaborative cross-cultural approach is needed to contextualise the international scale of the trend and thirdly, future research must be situated within a historical and generational perspective to understand declines in adolescent drinking in the context of a broader shift in adolescent behaviours.