Joint Developmental Trajectories of Conduct Problems and Hyperactivity/Inattention: Antecedent Risk Markers for Group Membership.

This study investigated joint trajectories of conduct problems and hyperactivity/inattention from age three to nine in a cohort of 7,507 children in Ireland (50.3% males; 84.9% Irish). The parent-reported Strengths and Difficulties Questionnaire was used to collect information on conduct problems (CP) and hyperactivity/inattention (HI). Information regarding risk markers was collected when participants were nine-months-old via parent report and standardised assessments. Using a person-centred approach (i.e., group-based multi trajectory modelling), six trajectories were identified: no CP/low HI, low-stable CP/HI, low-declining CP/stable HI, desisting co-occurring CP/HI, pure-increasing HI, and high chronic co-occurring CP/HI. Specific risk markers for group membership included: male sex; birth complications; perceived difficult temperament; lower primary caregiver age and education level, and higher stress level; prenatal exposure to smoking, and indicators of lower socioeconomic status. Primary caregiver-child bonding and having siblings were protective markers against membership in elevated groups. Results suggest support for both 'pure' HI and co-occurring trajectories of CP and HI emerging in toddlerhood. However, no support was found for a 'pure' CP trajectory, which may support the suggestion that children on a persistent CP trajectory will have coexisting HI. Intervention efforts may benefit from starting early in life and targeting multiple risk markers in families with fewer resources.