Disregard for rules: the early development and predictors of a specific dimension of disruptive behavior disorders Ame ´ lie Petitclerc, 1 Michel Boivin, 2 Ginette Dionne, 2 Mark Zoccolillo, 3 and Richard E. Tremblay 4 1 University College Dublin, Ireland; 2 Laval University, Quebec, Canada; 3 McGill University, Canada; 4 International Laboratory for Child and Adolescent Mental Health Development: INSERM U669, Paris, France; Universite ´ de Montre ´al, Canada; University College Dublin, Ireland Background:Disregard for rules, an important dimension of oppositional defiant and conduct disor- ders, is frequent during early childhood, but the development of its chronic form has not been studied during this key socialization period. This study aimed to describe the developmental trajectories of disregard for rules during early childhood and identify prenatal and postnatal predictors for a high trajectory. Methods:Participants were involved in a longitudinal study of a birth cohort followed yearly from 5 to 74 months of age (N = 1,942). Prenatal and postnatal predictors were measured by parental report at the beginning of the study, and parents reported child disregard for rules at five time points from 29 to 74 months of age. Results:Four groups of children followed distinct and stable trajectories of mother-rated disregard for rules: Very Low (approximately 9.1%), Low (56.9%), Moderate (29.7%) and Chronic (4.3%). As expected, male sex was a significant predictor of the chronic trajectory (OR = 1.76, CI = 1.09–2.83). Mothers’ history of antisocial behavior (OR = 1.72, CI = 1.02–2.91), and postnatal depressive symptoms experienced by the mother (OR = 1.71, CI = 1.03–2.84) and the father (OR = 2.02, CI = 1.10–3.71) were also important independent predictors. However, contrary to expectations, chil- dren’s difficult temperament and parenting at 5 months did not predict chronic disregard for rules beyond other risk factors. Conclusions:High disregard for rules is fairly stable during early childhood and is associated with risk factors identifiable before and shortly after birth which may be used for targeted prevention. Keywords: Oppositional defiant disorder, disruptive behavior disorders, devel- opmental trajectories, risk factors, child development, early childhood. Among community or primary care samples of chil- dren aged 2 to 5 years, it is estimated that 4% to 8% would meet DSM diagnostic criteria for oppositional defiant disorder (ODD) and up to 4% would meet criteria for conduct disorder (Egger & Angold, 2006). These early disruptive behavior disorders (DBD) are associated with significant impairment (Keenan & Wakschlag, 2000) and are a source of considerable parental concern (Stallard, 1993). Central to the DBD, and to adult antisocial personality disorder and psychopathy, is repeated rule breaking that appears uncurbed by the experience of guilt or the fear of punishment, a pattern we label disregard for rules. Early childhood is particularly relevant to disregard for rules, because this period is marked by significant development of behavioral control, language, and self-evaluative skills, which progres- sively equip children to actively resist their parents’ rules, as well as to comply with and internalize these rules (Kaler & Kopp, 1990; Kochanska, Coy, & Murray, 2001; Kuczynski & Kochanska, 1990; Stipek, Gralinski, & Kopp, 1990). Because disregard for rules is fundamental to disruptive and antisocial behavior, and highly relevant in early childhood, knowledge about its early developmental course and risk factors is essential to guide preventive inter- ventions. Yet, this knowledge is currently limited because most studies of young children have combined sev- eral DBD symptoms and only a few have followed children longitudinally. In a sample of boys from low- income families, a small group (6.7%) was found to follow a high trajectory of mixed DBD symptoms (disregard for rules, temper tantrums, aggression) from ages 2 to 10 years (Shaw, Lacourse, & Nagin, 2005). These boys had younger mothers and, between 18 and 24 months of age, were more likely to exhibit a fearless temperament and be exposed to maternal depressive symptoms and maternal rejection, compared to boys following the lowest trajectory. In a study of DBD symptoms from 18 to 30 months of age, the best 18-month predictors were the child’s difficult temperament and physical health problems, maternal depressive-anxious symptoms and low social support (Mathiesen & Sanson, 2000). One study focusing specifically on noncompliance found that difficult temperament and maternal restrictive control in the first two years predicted persistent noncompliance observed at age 4 (Pettit & Bates, 1989). These results suggest that young motherhood, maternal personality and maternal distress, poor parenting, and a difficult or fearless Conflict of interest statement: No conflicts declared. Journal of Child Psychology and Psychiatry 50:12 (2009), pp 1477–1484 doi:10.1111/j.1469-7610.2009.02118.x Ó 2009 The Authors Journal compilation Ó 2009 Association for Child and Adolescent Mental Health. Published by Blackwell Publishing, 9600 Garsington Road, Oxford OX4 2DQ, UK and 350 Main Street, Malden, MA 02148, USA