Predicting girls' conduct disorder in adolescence from childhood trajectories of disruptive behaviors

Objective: To examine girls' developmental trajectories of disruptive behav iors during the elementary school years and to predict conduct disorder sym ptoms and diagnosis in adolescence with trajectories of these behaviors. Me thod: The sample was 820 girls from the province of Quebec followed over 10 years (1986-1996). A semiparametric mixture model was used to describe gir ls' developmental trajectories of teacher-rated disruptive behaviors betwee n the ages of 6 and 12 years. The trajectories were used to predict conduct disorder symptoms and diagnosis when the girls were on average 15.7 years. Results: Four groups of girls following trajectories with distinct levels of disruptive behaviors were identified: a low, medium, medium-high, and hi gh trajectory. Prediction with the trajectories indicated that girls on the medium, medium-high, and high trajectories reported a significantly higher number of conduct disorder symptoms in adolescence. However. only the girl s on the medium-high and high trajectories were at significantly higher ris k to meet DSM-III-R criteria for conduct disorder, compared with girls in t he low group (odds ratio: 4.46). More than two thirds of the girls with con duct disorder were in the medium or higher-level trajectories. Conclusion: The results suggest that there is an early-onset type of conduct disorder i n girls.