Comparative Mechanisms (Mediators, Moderators) of Psychosocial Chronic Pain Treatments

Chronic musculoskeletal pain (CP) is a major public health concern. A number of psychosocial treatments
have emerged in recent decades to help address this problem. These interventions have been shown to be
efficacious when compared to largely inert control conditions; however, recent meta-analyses indicate that
most of these treatments are characterized by modest effects on primary outcomes. This is a critical
shortcoming of these otherwise promising approaches. Rather than attempting to boost efficacy only by
developing new and hopefully more powerful interventions, we can also look within our already proven
treatments for ways to enhance the magnitude of treatment effects. One strategy is to increase our
understanding of treatment mediators. Studies of mediators are needed that directly compare different
treatments with each other to determine which mediators are treatment-specific, which are shared across
treatments, and which contribute the most to clinical outcomes. The findings from such research could be used
to inform adaptations to existing treatment that enhance their benefits. A second strategy for increasing the
beneficial effects of existing treatments is to identify the patient characteristics that moderate treatment
responses. Research is needed that is guided by theoretical models and that tests moderators across multiple
treatments. Identifying subgroups of patients more likely to respond to one or another treatment can advance
precision medicine by informing a priori patient-treatment matches that can optimize treatment effects. We will
compare the mechanisms and moderators of Cognitive-Behavioral Therapy (CBT), Acceptance and
Commitment Therapy (ACT), and Emotional Awareness and Expression Therapy (EAET). Examining the
mediators and moderators of these treatments holds great potential for advancing treatment development and
enhancing treatment efficacy. Adults with chronic spinal (axial) pain (N=460) will be randomly assigned to CBT,
ACT, EAET and to treatment-as-usual (TAU). Aim 1 is to identify specific and shared mediators across
treatments. Aim 2 is to identify moderators across treatments. This project can increase the effects of our
psychosocial chronic pain treatments by identifying the most powerful treatment mechanisms – specific and
shared -- and revealing for whom the mediator  outcome pathways are strongest. Via increased
understanding of mediator and moderators, more effective pain treatment approaches can be developed,
tested, and implemented.

Grant Number: 5R01NR020610-03
NIH Institute/Center: NIH
Principal Investigator: John Burns