Inhibitory Learning versus Habituation in an Experimental Exposure Intervention for People With Heightened Health Anxiety: Increase of Distress Tolerance as a Joint Mechanism of Change?

The Inhibitory Learning Theory (ILT; Craske et al., 2008) changed the focus of exposure-based treatment from erasing excitatory associations and fear reduction (habituation (HA)) to reinforcing inhibitory associations and fear toleration (inhibitory learning (IL)). Studies which directly compare both approaches, IL versus HA, are scarce. The present study aimed at implementing and comparing an IL-based (n = 26; Age: M = 23.59, SD = 4.38) with a HA-based (n = 28; Age: M = 25.46, SD = 6.22) experimental exposure approach (including in vivo, interoceptive, and in sensu exposure) in a sample of people with heightened health anxiety. A significant pre- to post-intervention reduction of state health anxiety (p < .001), which was especially associated with an increase of distress tolerance (DT) pre- to post-exposure (F (1, 50) = 12.2, p < .001, ηp2 = .20), was observed. A superiority of the IL-based over the HA-based exposure intervention was not detected in relation to major outcomes (e.g., state health anxiety), as well as in relation to a change of DT. The present study underlines the importance of strengthening DT (for heightened health anxiety) during an exposure-based intervention.