Does pain mediate or moderate the relationship between physical activity and depressive symptoms in older people? Findings from The Irish Longitudinal Study on Ageing (TILDA)
Background. Depression is an increasing problem in older adults, which is exacerbated by under diagnosis and ineffective treatment options. Broadly speaking, as people age, their levels of regular physical activity (PA) decrease, while their experience of chronic pain increases. PA has been shown to be an effective, yet under-utilised, treatment for depression in this age-cohort although the influence of pain on the relationship between PA and depressive symptoms has not been considered. Methods. Secondary analysis of national data from The Irish Longitudinal Study on Ageing (TILDA, 2011) (n = 8163 participants aged 50 years and older) examined the mediating or moderating role of pain in the relationship between depressive symptoms and PA, and the impact of PA, pain and depressive symptoms on health-care utilisation. Results. Approximately 8.5% TILDA older adults were depressed. No mediating or moderating effects of pain were found in the association between PA and depressive symptoms. Higher levels of PA were found to be independently associated with lower depressive symptoms, while higher levels of pain significantly increased the likelihood of depressive symptoms supporting previous findings. Depressive symptoms and higher levels of pain were also found to significantly increase health-care utilisation. Conclusions. Consistent with previous findings in this field, both PA and pain were found to be independently associated with depressive symptoms in Irish older adults. Furthermore, pain does not play a mediating or moderating role in the relationship between PA and depressive symptoms. Continued support for ongoing initiatives in this area aimed at increasing PA in older adults as a means to improve both physical and mental well-being is advised. The absence of any synergistic effect between PA and pain suggests that clinicians and health service providers should continue to promote PA as a treatment for depression, irrespective of the pain levels of their patients.