The Effects of Socioeconomic Position on Endogenous Pain Modulation: A Quasi-Experimental Approach

Nandini Raghuraman; Titilola Akintola; Fenan R Rassu; Timothy D O'Connor; Shuo Chen; Ann Gruber-Baldini; Luana Colloca

doi:10.1016/j.jpain.2025.104778

The Effects of Socioeconomic Position on Endogenous Pain Modulation: A Quasi-Experimental Approach

J Pain. 2025 Jan 10:104778. doi: 10.1016/j.jpain.2025.104778. Online ahead of print.

Authors

Nandini Raghuraman¹, Titilola Akintola², Fenan R Rassu³, Timothy D O'Connor⁴, Shuo Chen⁵, Ann Gruber-Baldini⁵, Luana Colloca⁶

Affiliations

¹ Department of Pain Translational Symptom Science, School of Nursing, University of Maryland, Baltimore, USA; Graduate Program in Life Sciences, Program in Epidemiology and Human Genetics, University of Maryland School of Medicine, Baltimore, USA; Placebo Beyond Opinions Center, University of Maryland School of Nursing, Baltimore.
² Department of Pain Translational Symptom Science, School of Nursing, University of Maryland, Baltimore, USA; Center to Advance Chronic Pain Research, University of Maryland, Baltimore, USA; Placebo Beyond Opinions Center, University of Maryland School of Nursing, Baltimore.
³ Department of Physical Medicine and Rehabilitation, School of Medicine, The Johns Hopkins University, Baltimore, USA.
⁴ Institute for Genome Sciences, School of Medicine, University of Maryland, Baltimore, USA; Program in Health Equity and Population Health, School of Medicine, University of Baltimore, USA; Program in Personalized and Genomic Medicine, School of Medicine, University of Maryland, Baltimore, USA.
⁵ Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, USA.
⁶ Department of Pain Translational Symptom Science, School of Nursing, University of Maryland, Baltimore, USA; Center to Advance Chronic Pain Research, University of Maryland, Baltimore, USA; Department of Anesthesiology and Psychiatry, University of Maryland School of Medicine, Baltimore, USA; Placebo Beyond Opinions Center, University of Maryland School of Nursing, Baltimore. Electronic address: colloca@umaryland.edu.

PMID: 39800249
DOI: 10.1016/j.jpain.2025.104778

Abstract

Socioeconomic Position (SEP) is a multidimensional construct encompassing education, income, occupation, and neighborhood distress, influencing chronic pain severity, interference, and duration. However, its impact on placebo analgesia, where reduced pain perception occurs due to treatment belief, remains understudied. Using a quasi-experimental approach, we investigated SEP's influence on placebo analgesia in 401 participants with temporomandibular disorder (TMD) and 400 pain-free individuals. Using latent class analysis, we grouped participants into two SEP groups based on self-reported education, income, occupation, and neighborhood distress indices, including the area deprivation and distressed community indexes. Ancestry Informative Markers (AIMs) and self-reported race were included to account for genetic and demographic influences. Placebo analgesia was elicited using verbal suggestion and classical conditioning. Linear mixed models were employed to analyze SEP's impact, while multiple regression and ANCOVA assessed AIMs' and race's effects. Comparable placebo effects were observed between participants with TMD and pain-free individuals (F(1,4765.73) = 0.49, p = 0.48). A trend was noted in the main effect of SEP (F(1,4764.5) = 3.64, p = 0.056). Among TMD participants, those with distressed SEP exhibited lower placebo analgesia (F(1,4765.73) = 7.9, p = 0.005), while placebo response did not differ by SEP in pain-free participants (F(1,4765.73) = 0.27, p = 0.59). East Asian ancestry (β = 5.71, 95% CI [1.50, 9.92]) and self-reported Asian (mean = 24.20, sem = 1.52, p = 0.020) were associated with greater placebo analgesia. This study highlights the interplay of SEP, AIMs, and race in placebo analgesia and calls for tailored pain management interventions. PERSPECTIVE: SEP significantly contributes to pain disparities. This quasi-experimental study demonstrates analogous placebo analgesia between chronic pain and pain-free individuals but finds lower placebo analgesia only among individuals with chronic pain and distressed SEP. This highlights a link between chronic pain, SEP, and impaired placebo effects, suggesting new avenues for research.

Keywords: Ancestry Informative Markers; Conditioning; Expectations; Latent Class Analysis; Pain severity; Placebo; Social disparities.