Human Studies

This study examined psychosocial pain treatment moderation in a secondary analysis of a trial that compared cognitive therapy (CT), mindfulness-meditation (MM), and mindfulness-based cognitive therapy (MBCT) for chronic low back pain (CLBP). The Limit, Activate and Enhance (LA&E) model of moderation provided a framework for testing a priori hypotheses. Adult participants (N=69) with CLBP completed a pre-treatment assessment of hypothesized moderators: pain catastrophizing, brain state as assessed by electroencephalogram, mindful observing, and non-reactivity. Outcomes were pain interference, characteristic pain intensity, physical function, and depression, assessed at pre- and post-treatment. Moderation analyses found significant interaction effects, specifically: (1) higher and lower baseline pain catastrophizing was associated with greater improvement in pain intensity in MM and MBCT, respectively; (2) higher baseline theta power was associated with greater improvement in depression in MBCT and interfered with response to CT; (3) lower baseline non-reactivity was associated with greater improvement in physical function in MM while higher non-reactivity was associated with greater improvement in MBCT. The findings support the possibility that different patients are more or less likely to benefit from various treatments. Theory-driven moderation research has the capacity to inform the development of patient-treatment matching algorithms to optimize outcome. Perspective: This study presents preliminary findings from theory-driven tests of the moderators of mindfulness meditation, cognitive therapy and mindfulness-based cognitive therapy for chronic low back pain. The results of such analyses may inform the understanding of for whom various evidence-based psychosocial pain treatments may engender the most meaningful benefits.

Chronic low back pain (CLBP) is a major cause of global disability and improving management is essential. Acceptance and Commitment Therapy (ACT) is a promising treatment for chronic pain but has not been modified for physical therapy. This randomized controlled trial (RCT) compared physical therapy informed by Acceptance and Commitment Therapy (PACT) against standard care physical therapy for patients with CLBP. Patients with CLBP (duration ≥12 weeks, mean 3 years) were recruited from physical therapy clinics in four UK public hospitals. The Roland-Morris Disability Questionnaire (RMDQ) at 3 months' post randomization was the primary outcome. 248 participants (59% female, mean age=48) were recruited and 219 (88•3%) completed measures at 3 and/or 12 months' follow-up. At 3 months, PACT participants reported better outcomes for disability (RMDQ mean difference =1•07, p=0•037, 95%CI -2•08 to -0•07, d=0•2), Patient Specific Functioning (p=0.008), SF12 physical health (p=0.032), and treatment credibility (p<0.001). At 12 months' follow-up there were no significant differences between groups. PACT was acceptable to patients and clinicians and feasible to deliver. Physical therapists incorporated psychological principles successfully and treatment was delivered with high (≥80%) fidelity. Our results may inform the management of CLBP, with potential benefits for patients, health care providers and society. PERSPECTIVE: Psychologically informed physical therapy has great potential but there are challenges in implementation. The training and support included in the PACT trial enabled the intervention to be delivered as planned. This successfully reduced disability in the short but not long term. Findings could inform physical therapists' treatment of CLBP.

Previous studies have indicated a positive relationship between self-compassion and psychological and emotional well-being in chronic pain populations. However, evidence on the role and mechanisms of self-compassion in pain perception is largely limited. The current study was designed to investigate the effects and a potential mechanism of self-compassion on experimental pain. Thirty healthy participants underwent a compassionate self-talk protocol, which was followed by cold pain exposure during which high-frequency heart rate variability (HF-HRV) was evaluated. The compassionate self-talk protocol successfully generated compassionate statements among the participants. Our behavioral data showed lower pain ratings in the self-compassion compared to the control condition. Moreover, self-compassion manipulation resulted in higher HF-HRV during pain, which was associated with lower pain ratings. We present interesting findings that a short period of compassionate self-talk may decrease experimental pain as well as mechanistic evidence surrounding bodily control over pain-related arousal indicated by HF-HRV. PERSPECTIVE: This study presents the first line of evidence that a short period of compassionate self-talk may be sufficient to reduce experimental pain. We also demonstrate increased bodily control as a potential mechanism underlying this effect.

Pain assessment and treatment is challenging among persons with dementia (PWDs). To better understand reports of pain interference, we examined ratings made by PWDs, as well as corresponding ratings about PWDs, as reported by the caregiver. We aimed to assess alignment between and predictors of caregiver and PWD report of pain interference.

To investigate prognostic factors for physical and emotional functioning following interdisciplinary multimodal pain rehabilitation, by targeting patients' baseline characteristics and health measures.