Heterogeneity in Fear Processing across and within Anxiety, Eating, and Compulsive Disorders

Abstract

BACKGROUNDTo assess within and across diagnosis variability we examined fear processing in healthy controls (HC) and three diagnostic groups that share symptoms of pathological anxiety: obsessive compulsive disorder (OCD); social anxiety disorder (SAD), and anorexia nervosa (AN). METHODSUnmedicated adults (N=166) participated in a paradigm assessing associative fear acquisition, extinction, extinction recall, and fear renewal. Data were analyzed from two perspectives: comparison of each disorder to HC and exploratory latent class analysis (LCA) of the combined data. RESULTSThe diagnosis-based analyses indicated significantly increased fear renewal in OCD and trends toward decreased extinction recall in OCD and increased renewal in SAD. The LCA indicated four Response Types, none of which were congruent with the diagnostic categories. Most participants had a normative response (50%) or a moderate extinction recall deficit (30%). The two remaining groups (8% each) had more extreme responses: one showed complete failure of extinction recall; the other persistent arousal in expectation of, but prior to, actual conditioning (threat sensitivity). LIMITATIONSDue to small sample size (N=20) results for AN are regarded as preliminary. CONCLUSIONSOur diagnosis-based findings are consistent with previous data suggesting an association between pathological anxiety and difficulties maintaining fear extinction. The LCA reveal substantial within-diagnosis heterogeneity in fear processing and support inclusion of empirically driven approaches as a complement to standard analyses. This heterogeneity may also have implications for treatment, particularly cognitive behavioral therapy, which relies on strengthening extinction recall and requires patients to tolerate anxious expectation in order to engage with feared situations.