To give an update on current knowledge about the comorbidity of pain and psychoaffective diseases

Literature search (MEDLINE, PsycINFO, SCOPUS), summary of recent own data

Epidemiological studies report a mean prevalence rate of major depressive disorder in patients with chronic pain assessed in pain clinics of 52%, and a mean prevalence of pain in depressed patients of 65%. Patients with the fibromyalgia syndrome are 4.3 times more likely than healthy control subjects to develop major depressive disorder and 4.7 times more likely to develop an anxiety disorder. The prevalence of anxiety disorders in patients with chronic arthritic pain is elevated relative to the general population (35 vs. 17%). Similar numbers have been reported for migraine and chronic back pain. Many biological factors overlap in patients with depression, chronic pain, and the fibromyalgia syndrome. For example, both patients with depression and patients with chronic pain often have cytokine profiles shifted toware the pro-inflammatory side. The downregulation of the neurotrophic factor brain-derived neurotrophic factor (BDNF) is another common finding in pain and depression. Common genetic determinants have been described.

There is a high comorbidity between pain, depression, and anxiety. The causative connection between these disorders remains to be elucidated. A common biological basis has been hypothesized.