Baseline Chronic Pain Intensity and Long‐Term Depressive Symptoms in French Older Community‐Dwelling Adults: A 12‐Year Prospective Cohort Study

BACKGROUND: Chronic pain (CP) in older adults was associated with depression in numerous cross-sectional studies. However, the longitudinal link between CP characteristics and depressive symptoms in this population remains unsettled. We aimed to assess the prospective link between CP intensity and long-term depressive symptoms in a population-based cohort of older participants, considering numerous potential confounders. METHODS: The study sample was gathered from the PAQUID study, a prospective cohort study of community-dwellers above 65. Information regarding CP characteristics was collected at the 3-year follow-up visit. The sample included the 742 participants who fulfilled this CP questionnaire. Three CP groups were distinguished: no (n = 504), mild (n = 101), and intense (n = 137) CP. Depressive symptoms were assessed with the Center for Epidemiologic Studies Depression scale (CES-D) every 2-3 years during 12 years (6 waves). The association between CP and the 12-year CES-D course (12 years after the 3-year visit) was investigated using a multivariate latent process mixed model for curvilinear data. RESULTS: Compared with the participants without CP, those with moderate and intense CP had significantly higher CES-D levels at baseline with a dose-response relationship as a function of pain intensity (β = 0.366, p = 0.0308; 0.607, p < 0.0001, respectively). However, the time course was comparable in the three groups (β = -0.003, p = 0.8351; -0.003, p = 0.8516, for mild and intense CP, respectively). CONCLUSION: CP intensity is associated with higher levels of depressive symptoms persisting throughout the long period of follow-up. This finding reinforces the importance of early treatment of CP in older adults to prevent its sustainable psychological consequences. SIGNIFICANCE STATEMENT: Depression and chronic pain (CP) have been frequently associated in older adults. The longitudinal relationship between CP characteristics and the long-term course of depressive symptoms in this population has yet to be specified. The present results showed that CP intensity is associated with higher levels of depressive symptoms persisting throughout a 15-year follow-up period, with a dose-response relationship. This finding reinforces the importance of early treatment of CP in the older population, in order to prevent its lasting psychological consequences.