Objective-Behavioral inhibition (BI), a temperamental style identifiable in early childhood, is considered a risk factor for the development of anxiety disorders, particularly social anxiety disorder (SAD). However, few studies examining this question have evaluated the stability of BI across multiple developmental time points and followed participants into adolescence-the developmental period during which risk for SAD onset is at its peak. The current study used a prospective longitudinal design to determine whether stable early BI predicted the presence of psychiatric disorders and continuous levels of social anxiety in adolescents. It was hypothesized that stable BI would predict the presence of adolescent psychiatric diagnoses, specifically SAD.Method-Participants included 126 adolescents aged 14 to 16 years who were first recruited at 4 months of age from hospital birth records. Temperament was measured at multiple time points between the ages of 14 months and 7 years. In adolescence, diagnostic interviews were conducted with parents and adolescents, and continuous measures of adolescent-and parent-reported social anxiety were collected.Results-Stable maternal-reported early BI was associated with 3.79 times increased odds of a lifetime SAD diagnosis, but not other diagnoses, during adolescence (95% confidence interval 1.18-12.12). Stable maternal-reported early BI also predicted independent adolescent and parent ratings of ongoing social anxiety symptoms.Conclusions-Findings suggesting that stable maternal-reported early BI predicts lifetime SAD have important implications for the early identification and prevention of SAD. Keywords temperament; behavioral inhibition; social anxiety disorderApproximately 15% to 20% of children can be classified as behaviorally inhibited during early childhood. This temperamental style involves the tendency to show signs of fear, reticence, or wariness in response to unfamiliar situations and to withdraw from unfamiliar peers. 1,2 Approximately half of all children categorized as extremely behaviorally inhibited continue to

The temperamental style of behavioral inhibition has been characterized by exaggerated behavioral and neural responses to cues signaling threat. Virtually no work, however, has addressed whether behavioral inhibition may also confer heightened brain activation in response to positively valenced incentives. We used event-related functional MRI (fMRI) and a monetary incentive delay task to examine whether the neural response to incentives is also greater in adolescents characterized as behaviorally inhibited early in life compared with those characterized as non-inhibited. Whereas task performance did not differ between groups, fMRI revealed greater striatal activation to incentives in behaviorally inhibited adolescents than in non-inhibited adolescents. This was regardless of whether the incentive was an anticipated gain or loss. Alteration in neural systems underlying behavior modulated by both negative and positive contingencies may represent a correlate of behavioral inhibition that also underlies vulnerability to various forms of developmental psychopathology.