Pain and Comorbid Psychiatric Illnesses in Elderly People
Chronic pain is often associated with anxiety, depression, and frailty. The relationship between pain and mental illness is complex and bidirectional. In elderly people, poor self-rated health is strongly associated with pain severity, and pain-related interference with daily activities leads to depression. There is a shared neural substrate within the central nervous system (CNS) between pain and depression, which have a common neuroanatomical organization within the CNS. The close association between pain and depression means that assessment of pain should be accompanied by assessment of depression even if by the single question, “Are you depressed?” The physiological changes in aging influence the pain experience and analgesic tolerance, which diminishes in the presence of comorbidities. Tolerance to antidepressants is also diminished, with a greater risk for drug–drug interactions due to polypharmacy, which accompanies older age.