Rationale and design of a multisite randomized clinical trial examining an integrated behavioral treatment for veterans with co-occurring chronic pain and opioid use disorder: The pain and opioids integrated treatment in veterans (POSITIVE) trial.

BACKGROUND: Chronic pain and opioid use disorder (OUD) individually represent a risk to health and well-being. Concerningly, there is evidence that they are frequently co-morbid. While few treatments exist that simultaneously target both conditions, preliminary work has supported the feasibility of an integrated behavioral treatment targeting pain interference and opioid misuse. This treatment combined Acceptance and Commitment Therapy (ACT) and Mindfulness-Based Relapse Prevention (ACT+MBRP). This paper describes the protocol for the adequately powered efficacy study of this integrated treatment. METHODS: A multisite randomized controlled trial will examine the efficacy of ACT+MBRP in comparison to a parallel education control condition, focusing on opioid safety and pain education. Participants include veterans (n = 160; 21-75 years old) recruited from three Veterans Administration (VA) Healthcare Systems with chronic pain who are on a stable dose of buprenorphine. Both conditions include twelve weekly 90 min group sessions delivered via telehealth. Primary outcomes include pain interference (Patient Reported Outcome Measurement Information System - Pain Interference) and hazardous opioid use (Current Opioid Misuse Measure), which will be examined at the end of the active treatment phase and through 12 months post-intervention. Secondary analyses will evaluate outcomes including pain intensity, depression, pain-related fear, and substance use, as well as treatment mechanisms. CONCLUSION: This study will determine the efficacy of an integrated behavioral treatment program for pain interference and hazardous opioid use among veterans with chronic pain and OUD who are prescribed buprenorphine, addressing a critical need for more integrated treatments for chronic pain and OUD. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04648228.

Emotional modulation of pain and spinal nociception in persons with major depressive disorder (MDD).

Major depressive disorder (MDD) is associated with risk for chronic pain, but the mechanisms contributing to the MDD and pain relationship are unclear. To examine whether disrupted emotional modulation of pain might contribute, this study assessed emotional processing and emotional modulation of pain in healthy controls and unmedicated persons with MDD (14 MDD, 14 controls). Emotionally charged pictures (erotica, neutral, mutilation) were presented in 4 blocks. Two blocks assessed physiological-emotional reactions (pleasure/arousal ratings, corrugator electromyography (EMG), startle modulation, skin conductance) in the absence of pain and 2 blocks assessed emotional modulation of pain and the nociceptive flexion reflex (NFR, a physiological measure of spinal nociception) evoked by suprathreshold electric stimulations. Results indicated pictures generally evoked the intended emotional responses; erotic pictures elicited pleasure, subjective arousal, and smaller startle magnitudes, whereas mutilation pictures elicited displeasure, corrugator EMG activation, and subjective/physiological arousal. However, emotional processing was partially disrupted in MDD, as evidenced by a blunted pleasure response to erotica and a failure to modulate startle according to a valence linear trend. Furthermore, emotional modulation of pain was observed in controls but not MDD, even though there were no group differences in NFR threshold or emotional modulation of NFR. Together, these results suggest supraspinal processes associated with emotion processing and emotional modulation of pain may be disrupted in MDD, but brain to spinal cord processes that modulate spinal nociception are intact. Thus, emotional modulation of pain deficits may be a phenotypic marker for future pain risk in MDD.

Respiration-induced hypoalgesia: exploration of potential mechanisms.

UNLABELLED: Slow breathing is used as a means to reduce pain, yet the mechanisms responsible for respiration-induced hypoalgesia are poorly understood. The present study asked 30 healthy participants (M(age) = 21 years, M(education) = 15 years, 80% white non-Hispanic) to breathe at normal, slow (50% normal), and fast (125% normal) rates while constant-intensity, suprathreshold electric stimulations were delivered to the sural nerve to elicit pain and the nociceptive flexion reflex (NFR, a measure of spinal nociception). Stimulations were equally balanced across inhalations and exhalations to determine whether parasympathetic activation during exhalations contributes to hypoalgesia. Respiration rate, heart rate variability (HRV, a measure of parasympathetic activity), heart rate, and subjective arousal were assessed as manipulation checks. Slow breathing reduced pain relative to normal breathing and fast breathing, but NFR was not influenced by breathing. Further, pain and NFR did not differ between exhalations and inhalations, and changes in HRV did not correlate with changes in pain or NFR. Together, these findings suggest that respiration-induced hypoalgesia does not require gating of spinal nociception or changes in parasympathetic activity. PERSPECTIVE: Slow breathing reduced pain relative to normal and fast breathing. This respiration-induced hypoalgesia does not appear to be due to gating of spinal nociception or changes in parasympathetic activity.