Chronic pain and comorbid conditions

The great social and economic significance of chronic pain is universally recognized. The financial costs for treating back pain alone are three times higher than the costs of treating cancer patients. There is a well-founded opinion that the formation of chronic pain is more dependent on psychological factors than on the intensity of peripheral nociceptive effects.

It was found that the prevalence of major depression among all persons applying for primary health care is 5-10%, and the prevalence of depressive disorders that do not meet the criteria of major depression is 2-3 times higher. Worldwide, depression is the 4th among causes of disability, and by 2020 it is expected to take the 2nd place on this list, second only to oncological diseases. Depression (Latin depressio - suppression, oppression) is a mental disorder characterized by a pathologically lowered mood (hypotomy) with a negative, pessimistic assessment of oneself, one's position in the surrounding reality and one's future. Depressive mood change along with distortion of cognitive processes is accompanied by ideational and motor inhibition, decreased motivation for activity, somatovegetative dysfunctions.

Depressive symptoms adversely affect the social adaptation and quality of life of the patient.

A study of depression in somatic patients (in therapeutic, cardiac and neurological practice) in 2002 showed that 45.9% of patients had symptoms of depression; 22.1% of patients had mild disorders of the depressive spectrum, and 23.8% needed mandatory prescription of antidepressants. At the same time, there were no significant differences in the prevalence of depression in admission from therapists, cardiologists or neurologists. Correct diagnosis of depression is carried out only 10-55% of patients in the general medical network, and only 13% of them receive adequate therapy with antidepressants.

The most common is the relationship (comorbidity) of chronic pain and depression. Depression of varying severity is noted in approximately 50% of patients with chronic pain, and more than 20% of patients have criteria for a major depressive episode. JB Murray (1997) believes that with chronic pain, one must first of all look for depression, referring to the existing opinion that any chronic pain is caused by severe depression. According to other authors, the incidence of depression in chronic pain varies from 10% to 100%. Depression among patients with chronic pain is more common in women. The most controversial is not the fact of the comorbidity of chronic pain and depression, but the causal relationship between them. Three possible options are considered: chronic pain is the cause of depression, depression increases susceptibility to pain, chronic pain and depression are linked by common pathogenetic mechanisms. It was found that the presence of depression reduces pain thresholds, and the presence of anxiety and depression is associated, in particular, with a tension headache with the presence of trigeminal zones of pericranial and cervical muscles. In addition to depression in chronic pain, anxiety disorders often occur in the form of generalized disorder, panic disorder and post-traumatic disorder. Chronic pain syndromes are characterized by a combination of depression and anxiety. In 40-90% of patients with anxiety, depression was present in the past or is presently present. The comorbidity of anxiety and depression is a clinical reality, characterized by high prevalence and can not be reduced to random coincidences or methodological errors. In many patients, psychological disorders are combined with physical symptoms of fevovia: muscle tension, hyperhidrosis, nausea, dizziness, tachycardia, hyperventilation, increased frequency of urination and diarrhea.

More and more work has appeared recently. Indicating a common biochemical defect in the CNS in chronic pain and depression, the leading role in which is the insufficiency of monoaminergic systems of the brain, which is confirmed by the high effectiveness of antidepressants in chronic pain syndromes and the detection of intensive production of autoantibodies to serotonin, dopamine, noradrenaline in experimental animals with neuropathic syndrome. Experimental studies have shown that pain syndrome is more severe when its development is preceded by the development of a depressive syndrome, rather than a rupture.

Chronic pain also depends on the characteristics of personal development, the presence of similar problems in close relatives, and the factor of "beaten paths" after trauma, surgical interventions, somatic diseases.

[1], [2], [3], [4], [5]