[영문]BACKGROUND: The primary aim was to examine correlated growth trajectories and reciprocal effects between academic achievement and drug use over the course of junior high school.METHODS: One hundred and three male and 98 female students from 3 rural junior high schools were surveyed 4 times over the course of 3 years. Dual trajectory latent growth models were estimated.RESULTS: Growth trajectories of school achievement and drug use over the course of junior high were highly correlated. Students who demonstrated deteriorating achievement during the course of junior high school showed an increase in drug use during this same time frame. Cross-process regressions indicated that students who demonstrated superior academic achievement in sixth grade exhibited a shallower rate of increase in drug use (ie, their drug use escalated to a lesser extent).CONCLUSIONS: The processes of academic disengagement (as marked by deteriorating grades) and drug use during adolescence appear to be related to one another. Prevention initiatives aimed at keeping adolescents academically engaged in school may have protective benefits against escalation of drug use.