Fear Conditioning in Adolescents With Anxiety Disorders: Results From a Novel Experimental Paradigm

Abstract

Objective-Considerable research examines fear conditioning in adult anxiety disorders but few studies examine youths. Adult data suggest that anxiety disorders involve elevated fear but intact differential conditioning. We used a novel paradigm to assess fear conditioning in pediatric anxiety patients.Method-Sixteen individuals with anxiety disorders and 38 healthy comparisons viewed two photographs of actresses displaying neutral expressions. One picture served as the conditioned stimulus (CS), paired with a fearful expression and a shrieking scream (CS+), whereas the other picture served as a CS unpaired with the aversive outcome (CS−). Conditioning was indexed by selfreported fear. Subjects participated in two visits involving conditioning and extinction trials.Results-Both groups developed greater fear of the CS+ relative to CS−. Higher fear levels collapsed across each CS characterized anxious relative to healthy subjects, but no significant interaction between group and stimulus type emerged. Fear levels at visit 1 predicted avoidance of visit 2. Fear levels to both CS types showed stability even after extinction.Conclusions-Consistent with adult data, pediatric anxiety involves higher fear levels following conditioning but not greater differential conditioning. Extending these methods to neuroimaging studies may elucidate neural correlates of fear conditioning. Implications for exposure therapies are discussed. Keywords pediatric anxiety disorders; fear conditioning; extinctionFear conditioning is the process by which a neutral stimulus (e.g., tone) acquires the feareliciting properties of an aversive unconditioned stimulus (e.g., shock) through repeated pairings of these stimuli. Associative learning mechanisms enable the neutral stimulus to become a conditioned stimulus (CS) that evokes fear independently of the unconditioned stimulus (UCS). Extinction, by comparison, is the process by which fear associated with the CS declines after repeated presentation of the CS in the absence of the UCS. Many theories

Integrating research on development and fear learning: a vision for clinical neuroscience?

“…This is because the neural correlates of many anxiety-related states each appear to be heavily context specific; the amygdala response to threats in healthy children, pediatric anxiety disorders, and pediatric major depressive disorder can appear similar when children are cued to attend to some aspects of threats. [14,15] In other contexts, when children are cued to attend to other aspects of threats, both pediatric anxiety and major depressive disorders can appear similarly hypersensitive to threats, whereas in still other contexts, all three groups of children can appear distinct, in terms of their amygdala-based sensitivities. [9] Thus, experimental manipulation of the psychological context can either acutely unmask or obscure anxiety-related between-group differences in fear-circuit function.…”

“…As predicted, anxious children and adolescents studied with this paradigm develop greater fear responses than healthy individuals to conditioned fear cues; moreover, as in both clinically anxious adults and animal models of pathological anxiety, these increased responses appear indiscriminately to both conditioned and unconditioned cues. [14,15] Thus, data in adults suggest that one fundamental deficit in anxiety disorders is a lowering of the threshold for eliciting defensive behavior, due to failure to discriminate appropriately overt as opposed to ambiguous threats. Figure 1 illustrates potential methods for evaluating with precision the ability of anxious youth to exhibit discriminate responding in such circumstances.…”

Distinct neural signatures of threat learning in adolescents and adults

“…To overcome these barriers, we developed a unique task that capitalizes on the intrinsic aversiveness of witnessing fear in others (24). Thus, the task uses a fearful facial expression paired with a scream as the UCS (23). This UCS is paired with a photograph of one actor, the CS+ (threat stimulus), but is never paired with a photograph of another actor, the CS− (safety stimulus) (Fig.…”

“…Ethical factors complicate this work. Electrical shocks, the most widely used UCS in adults, may not be appropriate for adolescents, yet less noxious UCSs typically provoke minimal fear in adolescents (23). To overcome these barriers, we developed a unique task that capitalizes on the intrinsic aversiveness of witnessing fear in others (24).…”

Tenho medo de quê?

“…Objects and situations that are in principal neutral come to be symbolically charged and become external objects of phobia. This can then trigger avoidance behaviors to escape from situations that arouse anxiety (7,8) . In this manner, problems resolving psychosocial tasks make people more susceptible to fears and insecurities (9) .…”