Pain and depressive symptoms are highly prevalent in American veterans 50 years of age or older, and both pain and depressive symptoms seem to have reciprocal effects in this population, according to study findings published in Pain Medicine.
Depression and chronic pain are more prevalent among American veterans. Previous estimates suggest chronic pain in veterans can range from 25%-72%, while 66.7%-69.8% of veterans 50 years of age or older report pain, and 7.1%-11.6% report severe pain. Yet, there is limited long-term data on how pain and depression relate to each other in this patient population.
The objective of the current study was to examine the relationship between depressive symptoms and pain in a group of older American veterans.
The study relied on data from the ongoing, observational Health and Retirement Study (HRS), which included Americans 50 years of age or older. Data in the HRS are collected either in person or via telephone every 2 years. For the study, the researchers relied on data for veteran respondents from the 2002 to 2016 waves of the HRS (n=4302).
The researchers assessed depressive symptoms in the cohort, which was based on the 8-item modified version of the Center for Epidemiologic Studies Depression scale. Additionally, 2 questions focused on the presence and degree of pain were also assessed in the veteran respondents.
A cross-lagged panel model (CLPM) was compared with 2 random-intercepts CLPMs (RI-CLPM), all of which evaluated the association between pain and depressive symptoms during the 2002 to 2016 HRS waves. The first RI-CLPM assessed the bivariate relationship between pain and depressive symptoms. In contrast, the second RI-CLPM adjusted for several baseline demographic variables including age, self-reported health, years of education, marital/partner status, race/ethnicity, and sex. According to the researchers, the RI-CLPM was previously developed to examine reciprocal effects between variables over time.
In the 2002 wave, approximately 26% of respondents endorsed being troubled with pain, including mild pain (30.55%), moderate pain (55.12%), and severe pain (14.32%). The traditional CLPM demonstrated poor fit across indices, and the researchers reported equivalent cross-lagged effects of pain on depressive symptoms and depressive symptoms on pain.
The adjusted RI-CLPM showed good fit across fit indices overall, and the adjusted model pointed to evidence that suggests depressive symptoms and pain feature a trait-like component. Additionally, there appeared to be an association between these trait-like characteristics. Overall, the researchers concluded their analysis shows evidence for a “roughly equivalent” yet “very small” reciprocal effect between symptoms of depression and pain in this older veterans’ population during the 14-year period.
A limitation of the study included the use of only 2 questions to measure pain. The researchers suggest a more comprehensive approach to pain assessment could use a multidimensional scale assessed for psychometric properties.
Despite these limitations, the researchers wrote that the “findings suggest that clinicians should treat both depressive symptoms and pain, rather than assume that treatment benefits in one domain will lead to major benefits in another.”
Griffin SC, Young JR, Naylor JC, Allen KD, Beckham JC, Calhoun PS. Reciprocal effects between depressive symptoms and pain in veterans over 50. Pain Med. Published online October 13, 2021. doi:10.1093/pm/pnab294