The relationship between risk factors and adolescent behavior is complex, especially when examining this behavior from a multidimensional, dynamic perspective. The ecological-developmental perspective has emerged as a theoretical framework from which to examine the ever-changing relationship between risk factors and adolescent substance abuse. Five types of change-based mechanisms are identified from the research literature: (1) the changing nature of risk-related norms and expectations that are tied to certain historical periods or eras; (2) individual development which leads to changes in certain risk factors; (3) the notion that drug use progresses and escalates over time; (4) the chain of influence, or chain risk, that begins in early or middle childhood; and (5) the co-occurrence of risk factors, known as cumulative risk. Research that has examined how each of these mechanisms affects adolescent substance abuse is reviewed in turn, followed by a discussion about implications for future research. Several gaps were identified in the understanding of how changes in risk factors related to adolescent substance abuse. Future research should focus on clarifying the changes in risk factors that correspond to changes in particular historical periods and how cumulative risk impacts substance abuse. References