Targeting avoidance via compound extinction

Avoidance towards innocuous cues is a key diagnostic criterion across anxiety-related disorders. Importantly, the most effective intervention for anxiety-related disorders, exposure therapy with response prevention, sometimes does not prevent the relapse of anxiety's symptomatology. We tested whether extinction effects, the experimental proxy of exposure, are enhanced by increasing the discrepancy between the prediction of an unpleasant event happening (shock presentation), and the actual event (shock omission). Forty-eight individuals first saw pictures of three stimuli. Two pictures (CSA, CSB) were followed by a shock (US) and one (CS-) was not. Next, participants learned to avoid the US by pressing a computer key. An extinction and response prevention procedure followed. In the first part of it, participants saw unreinforced presentations of all CSs. In the second part, the single group saw unreinforced presentations of the CSA and CS-. The compound group encountered compound unreinforced presentations of the CSA and CSB, and separate presentations of the CS-. Return of avoidance and fear was tested after unsignalled presentations of the US. Compound extinction resulted in comparable reduction of fear and avoidance compared to standard extinction. We discuss how future research could enhance extinction effects by adding costs to the avoidance behaviour.