Fear extinction in anxiety patients Comparing the different fear responses of anxiety patients and healthy controls and assessing the predictive value of fear extinction on exposure therapy treatment outcome.

Abstract

Fear conditioning is often used in research to study which processes are involved in the extinction of fear. Comparing the fear extinction abilities of anxiety patients with healthy controls can enhance knowledge in how to treat anxiety disorders and comparing an anxiety patient’s fear extinction before and after treatment can give valuable insight into the predictive value of fear extinction. A total of 135 participants, of which 70 were anxiety patients and 65 were healthy controls, participated in a fear conditioning experiment containing five phases; the habituation, uninstructed acquisition, instructed acquisition, uninstructed extinction and instructed extinction phase. Of those anxiety patients, 13 participated in the follow-up measurements. During each phase, pictures of two neutral faces served as either a danger cue (CS+) or a safety cue (CS-). During the acquisition phases of the conditioning task, an electric shock (US) was only administered after the CS+ was displayed. During the instructed phases, the participants were informed about the CS-US relationship. The subjective anxiety scores and the expectancy of a shock scores were measured using a VAS scale (0-100) and the objective anxiety was measured using startle responses that were provoked by aversive noises. Results demonstrate that anxiety patients show stronger fear responses to the CS+ and CS- than the control group in the extinction phases. There were no significant differences in how well both groups could discriminate the CS+ and the CS-. Finally, explorative studies demonstrated that anxiety patients had lower fearresponses at their post-treatment measurement in comparison with their pre-treatment measurements. Future research could focus on using fear-relevant stimuli, the use of verbal instructions or the use of Dcycloserine as an enhancer of fear extinction. It is important to further investigate the fear extinction process, because it is closely related to exposure therapy and could be of predictive value for treatment outcome.