Objective: To review preventive studies of disruptive behaviour disorders (DBDs) in light of recent empirical knowledge on their development.
Method: We draw on the results of longitudinal studies of children starting in infancy to examine the onset, development, and risk factors for DBD symptoms. We review randomized controlled trials of preventive interventions provided to families before the child is aged 3 years, with reported outcome measures of DBD symptoms at follow-up.
Results: Children who present high levels of DBD symptoms start to do so in the first 2 years of life and have risk factors that can be identified in the mother during pregnancy or even earlier, and shortly after the child's birth. Most preventive experiments have started relatively late after birth and have targeted parenting, with weak effects on children's DBDs. Preventive experiments that have provided intensive intervention to at-risk mothers starting during pregnancy have shown important effects in reducing key risk factors and some of the most severe consequences of DBDs. However, even those experiments have not succeeded in preventing childhood DBDs in the home and school contexts.
Conclusions: We suggest adopting a sequential, multitarget, intergenerational, experimental approach both to increase our knowledge about causal mechanisms and to increase our effectiveness in curbing DBDs and their serious lifelong consequences.
Can J Psychiatry. 2009;54(4):222-231.
Key Words: prevention, disruptive behaviour disorders, onset, developmental trajectories, risk factors, early childhood, attention-deficit hyperactivity disorder, oppositional defiant disorder, conduct disorder, aggression
Abbreviations used in this article
ADHD attention-deficit hyperactivity disorder
CBCL Child Behaviour Checklist
CD conduct disorder
DBD disruptive behaviour disorder
DSM Diagnostic and Statistical Manual of Mental Disorders
NFP Nurse-Family Partnership
ODD oppositional defiant disorder
RCT randomized controlled trial
SES socioeconomic status
Children's DBDs, which include ODD, CD, and ADHD, are a significant burden to children, their families, and society in general because of their prevalence, lifespan consequences, and economic costs. Symptoms of DBD are among the most common reasons for which children are referred to mental health specialists.1^* These symptoms (especially ADHD and CD) are associated with lower global functioning and have been shown to increase risk for numerous adjustment problems during adolescence and adulthood, such as academic failure, substance abuse, risky sexual behaviour, and antisocial behaviour.5"13 A person showing the most severe of these outcomes - dropping out of school, heavy drug use, and a criminal career - is estimated to incur costs between 1.7 and 2.3 million dollars in the United States.14 Thus the prevention of DBDs can potentially reduce not only the child's and their family's suffering but also substantial public costs.
The essential feature of ODD, as described by DSM-IV,15 is a persistent pattern of negativistic, hostile, and defiant behaviour, which includes overt disruptiveness and disregard for rules (for example, argues, refuses to comply, and blames others) and emotional dysregulation (for example, touchy and loses temper). CD is described as a persistent pattern of behaviour in which the rights of others and age-appropriate social norms are violated. It includes acts of physical aggression, destruction of property, deceitfulness or theft, and breaking major school or home rules.15 Finally, ADHD is characterized by age-inappropriate hyperactive and impulsive behaviour (for example, fidgets and difficulty waiting one's turn) and inattention (for example, easily distracted and difficulty sustaining attention, difficulty organizing tasks).15 There is substantial comorbidity between the DBD symptoms from early childhood onward, 16~19 and strong overlap between their early family risk factors. …