Positioning adolescence in the developmental timeline.

Adolescence, the second decade of life, bridges childhood and adulthood, but also represents a host of unique experiences that impact health and well-being. Lifespan theories often emphasize the continuity of individual characteristics and their contexts from childhood to adolescence, underscoring the distal influence of childhood experiences. Yet, adolescence is marked by transitions that may provoke discontinuities, particularly within individuals, their contexts, and their interactions within those contexts. These discontinuities occur at varied times, orders, and intensities for individual youth, suggesting that adolescence may be a developmental turning point where earlier life experiences may be mediated, reversed, or transformed by proximal events. This perspective piece emphasizes the importance of considering transitions, discontinuities, and developmental turning points in adolescence as well as their potential to explain heterogeneity in adolescent and adult outcomes. We explore one biological and one contextual transition in adolescence and highlight innovative theories and methods for investigating continuity and discontinuity dynamics across development, which could lead to new insights related to the adolescent period and its importance in shaping future life trajectories.