The LPP indexes baseline and treatment-related changes in anxiety sensitivity.

Anxiety Sensitivity (AS) is one of the most well-researched transdiagnostic risk factors for psychopathology, making it an ideal intervention target for treatment of anxiety and mood pathology. Currently, there exists a gap in understanding underlying neural mechanisms of AS. The current study sought to examine the impact of 2 brief computerized interventions on AS in order to assess the P300 and late positive potential (LPP) event-related potential (ERP) components as an index of both baseline and treatment change in AS. Participants received one of the following, with a 1-month follow-up: an anxiety reduction intervention of cognitive anxiety sensitivity treatment (CAST), a mood intervention of cognitive bias modification interpretation (CBMI), a combined CAST and CBM-I intervention, or a repeated contact control group. Baseline AS was significantly related to baseline P3/LPP, such that higher P3/LPP amplitude (heightened emotional reactivity) is associated with higher AS at intake. Further, treatment-related reductions in AS were associated with higher baseline reactivity. Heightened emotional response was predictive of better treatment outcomes. Secondary analyses also revealed unique patterns in predictive utility of P3/LPP with posttreatment change in AS: the CAST group evidenced predictions of treatment outcome parietally, where the CBM-I group evidenced predictions frontally. The Combined group evidenced both frontal and parietal activations, consistent with combinatorial effects from the CAST and CBM-I groups. These findings suggest that the P3/LPP is an index of cognitive-affective processes underlying AS at baseline and has predictive ability in assessing AS treatment outcome in that our observed treatment types engage different neural mechanisms.