The impact of comorbid anxiety on the neuropsychological and clinical features of conduct disorder in adolescence

Conduct disorder (CD) is a common condition that emerges in childhood or adolescence, and is characterised by rule-breaking, aggression and delinquency. CD entails a considerable economic burden and is linked to unfavourable adult outcomes such as antisocial personality disorder and persistent criminality. CD therefore represents a considerable treatment need. However, it remains difficult to treat, and this is partly due to the extensive heterogeneity of the disorder. Part of this heterogeneity is a result of comorbidity with other disorders. There is converging evidence that links CD with anxiety disorders (ADs). However, the precise relationship between CD and ADs is as yet unclear: there is evidence for attenuating and exacerbating effects of ADs on CD severity and prognosis. Furthermore, little is known regarding the neuropsychological profile of individuals with comorbid CD+ADs compared to those with CD alone. This is important given that alterations in emotion processing have been implicated in the aetiologies of both CD and ADs.The present study investigated the effect of comorbid ADs on the clinical presentation and emotion processing styles of adolescents with CD, by comparing groups of adolescents with CD-only (n = 31), ADs-only (n = 23), comorbid CD+ADs (n = 20) and a typically-developing control group (n = 30). We used a range of clinical and questionnaire-based assessments, as well as a series of emotion processing tasks: three threat processing tasks and a facial emotion recognition task. We found that whilst the presence of comorbid ADs in CD had little effect on the clinical and personality characteristics of CD (e.g., callous-unemotional traits), individuals with comorbid CD+ADs performed differently on the emotion processing tasks compared to individuals with CD or ADs alone (and tended to perform similarly to controls, suggesting a protective effect of comorbid ADs). This suggests that the comorbid CD+ADs condition may represent a distinct disorder with its own distinct emotion processing style, which may have implications for the treatment of individuals with CD