Behavioral inhibition in boys with externalizing disorders

Abstract

Behavioral inhibition mechanisms make it possible to stop unwanted responses that have already been initiated before they are fully executed. This ability is particularly important in everyday situations in which behavioral goals change, behavior must still be suppressed because of possible consequences, or errors need to be corrected. Conversely, uncontrolled behavior results from an inhibition deficit. In ADHD, impulsive behavior is one of the three core symptoms. Children with conduct disorder (CD) also show impulsive behavior, often violating existing rules. In recent years, the theory has been proposed that impulsivity in hyperactive children is caused by a deficit in inhibitory control. However, because previous research findings are inconsistent and it remains unclear when boys with ADHD show an inhibition deficit and what effect comorbidity with conduct disorder has on inhibitory control, the present study examined four groups of participants (ADHD, CD, ADHD+CD, and controls) using a uniform study design and compared their results.