The most compelling argument in favor of interventions targeting children with early-onset externalizing disorders is the research documenting what happens in the absence of such intervention.
Preschool and school-age children who meet the diagnostic criteria for such externalizing disorders as oppositional defiant disorder and conduct disorder are at significantly increased risk for a range of adverse outcomes, including substance abuse, crime, mental illness, suicidality, and violence in adolescence and adulthood, as well as neglectful parenting.
According to the findings of a frequently cited longitudinal study reported in 2005, David M. Fergusson, Ph.D., and his colleagues at the University of Otago, Christchurch (New Zealand), observed a direct link between conduct disorder in middle childhood and poor psychological and social functioning in later life.
The investigators analyzed data gathered over 25 years from a birth cohort of 1,265 children, looking specifically at parent and teacher reports of child conduct problems at 7, 8, and 9 years old; measures of crime, substance use, mental health, sexual/partner relationships, and education/employment; and confounding factors such as childhood, family, and educational characteristics.
After controlling for confounding factors, statistically significant associations emerged between childhood conduct problems and the risk of adverse outcomes across all domains of functioning except education/employment. Those children with the most severe conduct problems at 7, 8, and 9 years old were up to 19 times as likely to exhibit these adverse outcomes, the authors reported (J. Child Psychol. Psychiatry 2005;46:837-49).
The association between early conduct disorder and specific adverse outcomes has also been examined. In a more recent report, Dr. Fergusson and his colleagues used data from the same birth cohort study to examine the association between conduct problems in middle childhood and adolescence and later substance use, abuse, and dependence. After controlling for confounding interpersonal factors, they found that conduct problems at 7-9 years and 14-16 years predicted substance use, abuse, and dependence at 18-25 years (Drug Alcohol Depend. 2007;88[suppl. 1]: S14-26).
In a study by Rolf Loeber, Ph.D., of the University of Pittsburgh and associates, boys diagnosed with conduct disorder in middle childhood were significantly more likely than their peers to carry a concealed gun in late adolescence.
Of 177 boys with behavioral disorders who were first interviewed between the ages of 7 and 12 years old, 20% of those with conduct disorder had carried a concealed gun by the time they were 18 years old. The researchers also found that adult crime was best predicted by gun carrying, conduct disorder, and lack of parental monitoring. "Of all psychiatric diagnoses, only [conduct disorder] was positively associated with gun carrying. This specific link probably rests on the association between delinquent-type symptoms of [conduct disorder], reflecting a delinquent lifestyle, and gun carrying," wrote the authors.
"Conduct disorder, even when controlling for self-reported violent behavior, maternal psychopathy [being diagnosed with a psychiatric disorder], victimization, and [lack of] parental monitoring, increased the risk of gun carrying by a factor of five," Dr. Loeber and his associates reported (Arch. Pediatr. Adolesc. Med. 2004;158:138-45).
The findings of these and other studies "highlight the developmental importance of addressing conduct difficulties in childhood and adolescence," according to Dr. Fergusson. It is critical, he said, to devise effective interventions and treatments to address these problems in order to stem the tide of consequent longer-term problems.
In light of data suggesting the importance of the early years to a child's later social development--specifically, that the pathways to violence and crime might be laid down by age 2 or 3 years and that the earlier aggressive and oppositional traits are established, the worse the long-term outlook tends to be--such interventions should be implemented early, before aggression and violence become stable character traits, suggested Daniel S. …