The pharmacological treatment of aggression in children and adolescents with conduct disorder. Do callous-unemotional traits modulate the efficacy of medication?

Background: Children and adolescents with conduct disorder (CD) show repetitive and persistent patterns of aggressive behaviour and the more severe forms are often associated with callous-unemotional (CU) traits. Objectives: To systematically review and, where data are adequate, conduct meta-analyses on the efficacy of medication on aggression in children and adolescent with CD considering the impact of CU traits. Results: Few studies have investigated patients with CD as primary diagnosis, and few of these have discriminated between different types of aggression or reported measures of CU traits. Methylphenidate and risperidone showed the largest effects on aggression in randomized controlled trials; other antipsychotics showed clinical efficacy on CD but this evidence is mainly revealed by open label trials. There is some low quality evidence to support a small effect of mood stabilizers and other agents. There were only two papers describing the effects of CU traits thus providing inconclusive results. Conclusion: Considering heterogeneity of the disorder, more proof-of-concept clinical studies are needed to define effects of medication and role of CU traits.