Bidirectional relationship between chronic pain and depressive symptoms in middle-aged and older adults

Objective: To assess the bidirectional association between chronic pain and depressive symptoms among middleaged and older adults from two prospective cohort studies. Methods: We used prospective data (12y of follow-up) from the English Longitudinal Study of Ageing (n n = 9149, 5018 women, 65.0 +/- 10.2y) and the Health and Retirement Study (n n = 16,883, 9810 women, 66.9 +/- 10.3y), including data from seven waves of each cohort between 2006 and 2018/2019. Depressive symptoms were assessed using the Centre of Epidemiological Studies Depression scale, while chronic pain was estimated using questions about the frequency of being troubled with pain. We used random-intercept cross-lagged panel models to assess the bidirectional association between pain and depressive symptoms, adjusting for potential confounders. Results: There was a cross-lagged effect of chronic pain on depressive symptoms (ELSA: R: 0.038; 95%CI: 0.011-0.066. Standardized coefficient (B): 0.021. SHARE: R: 0.044; 95%CI: 0.023-0.065. B: 0.023-0.024) as well as depressive symptoms on pain (ELSA: R: 0.010; 95%CI: 0.002-0.018. B: 0.017-0.019. SHARE: 0.011; 95%CI: 0.005-0.017. B: 0.020-0.021). Moreover, there were auto-regressive effects of both chronic pain (ELSA: R: 0.149; 95%CI: 0.128-0.171. SHARE: R: 0.129; 95%CI: 0.112-0.145) and depressive symptoms (ELSA: R: 0.149; 95%CI: 0.130-0.168. SHARE: R: 0.169; 95%CI: 0.154-0.184). Conclusion: We identified a modest bidirectional association between depressive symptoms and chronic pain, using two large prospective ageing cohorts.