University College London researches believe that middle-aged and older adults who experience pain are more likely to have had worsening symptoms of depression up to eight years before the pain began. The researchers found a similar trend for loneliness which increased both in the years before and after the onset of pain.
The study used data covering 21 years from the English Longitudinal Study of Ageing, in which a nationally representative population sample in England answers a wide range of questions every two years. The researchers compared survey data from 3,668 adults aged over 50 who often experienced moderate to severe pain with a matched group of the same number who did not.
In the pain group, they found that depressive symptoms got rapidly worse in the eight years prior to pain, peaked at the onset of pain, and remained high in the years after, whereas in the non-pain group depressive symptoms were less severe, less prevalent, and relatively constant.
The team suggest that factors such as depression and loneliness can contribute to pain through several mechanisms. By inducing stress, they may increase inflammation, which can lead to pain. They also may increase sensitivity to pain by changing immune responses and by dysregulating the autonomic nervous system, the network of nerves that control unconscious processes such as the ‘flight or fight’ response.
Given that depressive symptoms and loneliness worsen long before pain begins, suggests the potential for early mental health and social support to reduce or delay later pain.