Explicit and implicit memory bias in panic disorder with agoraphobia

Abstract

Thirty patients with a diagnosis of panic disorder with agoraphobia and 30 normal controls were compared on explicit memory (cued recall) and implicit memory (word stem completion) for positive, neutral, social threat, and physical threat words. The panic patients showed an explicit memory bias, but no implicit memory bias, for physical threat words. The index of explicit memory bias for physical threat words was found to correlate with anxiety sensitivity and degree of agoraphobic fear and avoidance. The index of baseline bias for threat words on the word completion task, on the other hand, correlated with trait anxiety. Although there were no correlations between explicit and implicit memory bias for physical threat words, explicit memory bias for physical threat words correlated with explicit memory bias indexes for positive words and social threat words. The results are discussed in terms of the functional role of an explicit memory bias for physically threatening events in panic disorder. The negative results on implicit memory bias are discussed in relation to earlier studies, the use of different implicit memory tasks, and the role of baseline bias on implicit memory tasks. Finally, the hypothesis is suggested that explicit and implicit memory bias for emotional information may represent two different styles of information processing, which serve as vulnerability factors for different emotional disorders.