To Örebro University

OBJECTIVES: We recently developed a transdiagnostic exposure treatment ("the hybrid treatment") for chronic pain patients with concurrent emotional difficulties. This paper investigates the hypothesized treatment processes, specifically: a) if changes on pain-related dysregulation (catastrophizing, fear-avoidance and non-acceptance of pain) and general emotion dysregulation (difficulties to regulate a broad spectrum of emotional responses) mediate effects on outcomes; and b) if mediation is more pronounced for patients who score higher on these processes pre-treatment.

METHODS: Structural equation modeling for longitudinal data using the full intention-to-treat sample was used to test whether proposed variables mediated the effect of the hybrid treatment (n=58) compared to a guided internet delivered pain management treatment based on cognitive-behavioral principles (iCBT; n=57) on pain interference and depressive symptoms at 9-months follow up. To make full use of the multiple process-measures collected in the trial, we modeled mediators as two continuous latent variables: pain-related dysregulation and general emotion dysregulation.

RESULTS: Reduced pain-related dysregulation mediated the effects of treatment on both outcomes, whereas reduced general emotion dysregulation mediated the effects on depressive symptoms only. In the hybrid treatment, the mediated effect was more pronounced for participants who scored higher on pain-related dysregulation pre-treatment relative to those who scored lower.

DISCUSSION: Our findings provide initial support for the transdiagnostic theoretical underpinnings of the hybrid treatment model. Using a hybrid treatment approach that centers on teaching patients emotion regulation skills before commencing broad exposure, successfully influenced both pain-related dysregulation and general emotion dysregulation, which in turn was associated with better treatment outcomes. It appears central to address these processes in pain patients with comorbid emotional problems, especially among patients scoring high on measures regarding catastrophizing, fear-avoidance and non-acceptance of pain.