It is thought that among children at a high risk for antisocial personality disorder, the level of individual anxiety might constitute an important marker with respect to symptomatology and prognosis. The aim of the present study was to examine whether associations between anxiety and subtypes of aggression (proactive and reactive) exist in boys with early-onset subtype of conduct disorder (CD) and co-morbid attention-deficit hyperactivity disorder (ADHD). A detailed psychometric characterization of boys with ADHD and the early-onset subtype of CD (n = 33) compared to healthy controls (n = 33) was performed. The assessment included trait anxiety, internalizing and externalizing problems, symptoms of psychopathy and temperament traits, as well as subtypes of aggressive behavior. Descriptive statistics, correlation analyses, and group comparisons were calculated. The clinical group was characterized by higher levels of externalizing and internalizing symptoms. Individual anxiety was positively associated with harm avoidance, symptoms of oppositional defiant disorder (ODD), and by trend with reactive aggression. In contrast, boys with reduced levels of anxiety exhibited more callous-unemotional traits. Our results indicate that children with the early-onset subtype of CD and ADHD constitute a psychopathological heterogeneous group. The associations between individual levels of trait anxiety, temperament traits, and subtypes of aggressive behavior in children with ADHD and severe antisocial behavior emphasize the impact of anxiety as a potential key factor that might also be crucial for improvement in therapeutic strategies and outcome measures. Anxiety should be considered carefully in children with ADHD and the early-onset subtype of CD in order to optimize current therapeutic interventions.

The current selective review emphasizes the heterogeneity of antisocial behaviour in children and adolescents. It focuses on the development of children of the early-starter subtype of conduct disorder who are at high risk for the development of an antisocial personality disorder. Especially the autonomic stress system seems to have an important impact on symptoms and the prognosis of antisocial individuals. While autonomic hypoarousal and a reduced autonomic reagibility seem to be associated with more proactive aggressiveness and a negative outcome, increased autonomic arousal and reagibility might be related to reactive aggressiveness and constitutes possibly a protective trait. Data of the current psychophysiological and neuroendocrinological literature are summarized. Moreover, the impact of comorbid attention deficit hyperactivity disorder and anxiety disorders on dissocial development is illustrated. Particularly early diagnostic assessment of the individual's extent of trait anxiety might help to specify therapeutic opportunities and could thereby improve therapeutic efficiency.