Fear conditioning and extinction in anxious and non-anxious youth: A meta-analysis.

Fear conditioning and extinction have been implicated in the etiology and maintenance of anxiety disorders. Most fear conditioning studies have been conducted with adult samples and the few published developmental studies in clinically anxious youth have yielded inconsistent results. The aim of the current review was to use meta-analysis to examine possible differences in fear conditioning and extinction in clinically anxious and non-anxious youth. Seven fear conditioning studies were included in the analysis, with a total of 160 clinically anxious and 166 non-anxious youth. All the studies included in the meta-analysis used a differential conditioning paradigm with at least one or more of the primary dependent variables: self-reported fear, skin conductance response (SCR) and fear potentiated startle (FPS). Similar differential fear acquisition and extinction patterns were observed in anxious and non-anxious individuals. However, anxious youth exhibited stronger fear responses to individual stimuli compared to their non-anxious counterparts. Results in clinically anxious youth resemble those reported in previous studies with clinically anxious adults. Importantly, due to the small number of fear learning studies conducted among youth, these results should be interpreted with caution. Further research is needed so as to better understand fear acquisition and extinction processes in developmental populations. In addition, future studies should focus on other fear-related learning processes such as differences in return of fear, retrieval of fear memory and more subtle differences in fear generalization.