[Depression and pain: prevalence and clinical implication].

Somatic pains are frequent in patients with major depression. Although they are not included in classical symptoms of depression, physical pains are found in 50-90% of depressed patient. They are more frequent in severe depressions, and especially in psychiatric inpatients with depression. Physical painful symptoms are good indices of depression severity and namely are predictive of poorer responses to treatments, and then of elevated rates of relapse when pains are persistent as residual symptoms after remission of the episode. More frequent pains in depressive patients are headaches, limb, back and joint pains. Aetiological hypothesis to explain the coexistence of physical pains and depression are based on the well-known dysfunction of the serotonergic and noradrenergic pathways in depression, which explains mood symptoms but also a lack of inhibitory control of ascending pain messages, normally controlled in spinal cord by descending serotonergic and noradrenergic projections. This phenomenon could explain the development of an interoceptive painful hypersensitivity, without external sensitivity. Antidepressants with dual serotonergic and noradrenergic actions are efficacious to treat chronic pains, for example in diabetic neuropathy. In line with monoaminergic hypotheses shown above, this is in favour of the use of these serotonin and norepinephrine reuptake inhibitors in depression with important physical pains, but this issue needs further confirmation studies.