Fear ConditionIng In Panic Disorder: Enhanced Resistance To ExtInction

Journal of Abnormal Psychology 2007, Vol. 116, No. 3, 612– 617

Copyright 2007 by the American Psychological Association 0021-843X/07/$12.00 DOI: 10.1037/0021-843X.116.3.612

Fear Conditioning in Panic Disorder: Enhanced Resistance to Extinction
Tanja Michael, Jens Blechert, Noortje Vriends, Jurgen Margraf, and Frank H. Wilhelm ¨
University of Basel
Enhanced conditionability has beenproposed as a crucial factor in the etiology and maintenance of panic disorder (PD). To test this assumption, the authors of the current study examined the acquisition and extinction of conditioned responses to aversive stimuli in PD. Thirty-nine PD patients and 33 healthy control participants took part in a differential aversive conditioning experiment. A highly annoying but not painful electricalstimulus served as the unconditioned stimulus (US), and two neutral pictures were used as either the paired conditioned stimulus (CS ) or the unpaired conditioned stimulus (CS ). Results indicate that PD patients do not show larger conditioned responses during acquisition than control participants. However, in contrast to control participants, PD patients exhibited larger skin conductance responsesto CS stimuli during extinction and maintained a more negative evaluation of them, as indicated by valence ratings obtained several times throughout the experiment. This suggests that PD patients show enhanced conditionability with respect to extinction. Keywords: anxiety disorders, panic attacks, classical conditioning, electrodermal activity, emotion

Fear learning is considered to be a highlyadaptive response to aversive events that ensures survival in changing and novel environments (LeDoux, 1995). One form of fear learning is fear conditioning (FC), which involves the pairing of a neutral (conditioned) stimulus (CS) with an aversive (unconditioned) stimulus (US). The CS becomes a signal for imminent US onset and thus provokes a conditioned response (CR). This serves to prepare theorganism for the US and the associated unconditioned response (UR). Extinction refers to the decrement in response to subsequent CS–alone trials, which is now recognized as additional learning (that the CS has a different meaning) rather than erasure of the original CS–US association (Bouton, 2002). Although FC is generally an adaptive process, it may turn into clinically relevant fear whenreactivity to the CS persists in the absence of a CS–US contingency. While FC accounts of anxiety disorders (ADs) have been widely criticized since the 1970s (Rachman, 1990), more recently a resurgence of interest has occurred. FC is an integral part of modern learning accounts of ADs that incorporate some complexities of contemporary learning theory and provide a compelling explanation for thedevelopment and persistence of ADs (e.g., Mineka & Zinbarg, 1996, 2006). Lissek et al. (2005) recently conducted a meta-analysis of FC studies of ADs that shows a modest elevation in both acquisition of fear and

Tanja Michael, Jens Blechert, Noortje Vriends, Jurgen Margraf, and ¨ Frank H. Wilhelm, Department of Clinical Psychology and Psychotherapy, Institute for Psychology, University of Basel, Basel,Switzerland. This research was supported by Swiss National Science Foundation Grants 105311-104038 and 105311-105850, and by a grant from the Academic Society of Basel (Freiwillige Akademische Gesellschaft Basel). We would like to thank Andrea Meyer for helpful suggestions with the statistical analysis, as well as Nathalie Erpelding, Rebecca Frey, and Tanja Meier for their help with the datacollection. Correspondence concerning this article should be addressed to Tanja Michael, University of Basel, Institute for Psychology, Missionsstrasse 60/62, CH-4055, Basel, Switzerland. E-mail: tanja.michael@unibas.ch 612

conditioned responding during extinction among anxiety patients. Thus, it has been proposed that AD patients are characterized by enhanced conditionability and that this is one...