Editorial: The passage of time

In this editorial, the author reflects on changes that occurred in the quality of research on developmental psychopathology over the last 35 years. This is illustrated in the increased quality of nine longitudinal studies that are included in the current issue of JCPP. Using approaches that capitalize on the passage of time, ranging from 28 days to 40 years across investigations, these studies employed multiple levels of analysis, used sophisticated statistical methods to control for confounding factors, included measurement at both the biological, cognitive, and behavioral levels, and collectively provided results that allow improved assessment of causality.