Chronic pain and depression

234 Columns Journal of Pain and Symptom Management Literature Update Chronic Pain and Depression Randal D. France Chronic pain is often an accompanying symptom seen in patients presenting with depressive disorder, I and depression is commonly seen in patients with chronic pain syndrome. 2 The incidence of pain in depressed patients is reported to vary from 30% to 80%, I and the incidence of depression in chronic pain patients ranges from 10% to 100%.:\ Pain in patients with indistinctive, cognitive, and emotional depressive symptoms has been conceptualized as masked depression 4 •5 or as a variant of depression. 6 Engel describes specific personality characteristics associated with patients likely to develop a chronic pain state. 7 He labelled these individuals as '''pain-prone'' patients. These patients commonly have the following: a masochistic personality, overwhelming guilt from conflicts over their own aggression or sexuality, reinforcement given by the parents during the time of an illness, and a restrictive upbringing. Engel states that this personality constellation can be seen in a variety of clinical psychiatric syndromes: conversion, depression, hysterical personality disorders, and anxiety disorders. Blumer has extended Engel's original concept and has described a group of patients with what he termed a "pain-prone disorder."6 These patients have continuous pain and often present with the desire for surgical treatment. These patients are moralistic and stoic and are described as solid citizen types. They have a limited education and initiate employment at an early age. He describes these patients as idealizing their family relationships and denying emotional or interpersonal conflicts, although 16% reported physical abuse. Psychological testing in these patients revealed an MMPI proRandal D. Francc, MD, is Assistant Professor of Psychiatry, Dukc Univcrsity ~fcdial Centcr, Durham, North Carolina. . file of rigidity, a strong need to present themselves in a positive image, and somatising during periods of stress. Projective tests showed evidence of depression, lying, rage, and dependency. Prior to the onset of pain, these patients are engaged in excessive activity; excessive passivity follows the onset of the pain. Blumer reported that 80% of these patients are depressed and stated that the pain-prone disorder can be viewed as a variant of depression. One does not have to evaluate many "chronic pain patients" referred for psychiatric evaluation to see the relevance in either Engel's or Blumer's descriptions. Blumer's hypothesis was supported by his studies of rapid eye movement (REM) latency in sleep and the dexamethasone suppression test (DST) in chronic pain patients. 8 Blumer et al reported that chronic pain patients had earlier escape of cortisol in response to a dexamethasone challenge, which is similar to the response of patients with major affective disorder. The frequency of reduced onset of REM latency in sleep of chronic pain patients was similar to the rate seen in patients with major depression. These findings strengthen the concept of the "pain-prone disorder" as a variant of depression and certainly justify chronic pain with no apparent etiology as a distinct psychopathologic condition. Indirect support is seen in the reduction of both pain and. depression in response to the administration of antidepressant medication. 9 - 11 However, the results of other studies on the prevalence of psychiatric disorders, the efficacy of antidepressants in chronic pain, and neuroendocrine studies in chronic pain patients do not support Blumer's hypothesis. In a survey of psychiatric diagnosis in a chronic pain clinic population, Fishbain et al 12 did show that at least 60% of the patients had a depressive ill- Vol. 2 No.4 Fall 1987 ness, but other psychiatric diagnoses were all commonly seen. Degrees of affective disturbance ' :' and subtypes of depression' can be reliably established in chronic pain patients. Furthermore, the severity of depressive symptomatology is related to the SUbtypes of depressive illness.' It appears unlikely that there is a simple psychopathological process explaining the occurrence of depression in chronic pain patients since different SUbtypes of depression and various degrees of depressive symtomatology occur in these patients. Studies have shown that the rate of DST nonsuppression is related to the presence or absence of major depression and not to chronic pain per se. 14 • 15 In addition, DST nonsuppression is not related to the presence or absence of organic findings in chronic pain patients. 14 Blumer's study of the DST in chronic pain patients,1l did not control for the presence or absence of major depression. Antidepressants have been shown to decrease pain complaints in chronic pain free of affective disturbance((;·'1l and independent of the drug effects on depressive symptomatology.I!'.:!! Furthermore, Bradleyll has demonstrated that in patients where pain and depression occur simultaneously, treatment for the depression resolves both conditions, whereas in patients where the onset of pain precedes the depression, treatment of affective disturbance is successful for depression but not pain. In a comprehensive literature review of the empirical studies on the relationship between chronic pain and depression, Romano and Turner concluded that the extent to which the two syndromes are associated remains unclear.:' However, the frequency of depressive symptomatology is higher in chronic pain patients than in the general and medical population. They cite methodological problems such as accurate assessment of pain and depression, selection of patient populations, and use of contrast groups as limiting the development of testable hypotheses explaining the relationship of chronic pain and depression. While the proposed disorder of the pain-prone patient as developed by Blumer remains intriguing, the studies testing this hypothesis are limited by the methodological problems described by Romano and Turner. Recent studies examining pain and depression fail to confirm the painprone disorder as a variant of depression. 235 Columns The relationship between chronic pain and depression remains obscure. Future studies designed to test models explaining this relationship should address the methods and issues reviewed by Romano and Turner. Despite the lack of data supporting the pain-prone disorder as a variant of depression, the clinical description outlined by Blumer certainly applies to a subgroup of chronic pain patients. It is hoped that an improved understanding of the relationship between chronic pain and depression can lead to more effective treatment of these conditions. References 1. FranceRD, Krishnan KRR, HollptJL, Urban BJ. Clinical characteristics of depression subtypes in chronic pain patients. Manuscript submitted for publication 11-86. 2. Hendler N. Depression caused by chronic pain. J Cline Psychiatry 1984;45:30-6. 3. RomanoJM, TurnerJA. Chronic Pain and depression: does the evidence support a relationship. Psychol Bull 1985;18-34. 4. Lesse S. Masked depression. A diagnostic and therapeutic problem. Dis Nerv Sytst 1968;29:16973. 5. Lopez-Ihor J]. Masked depression. Br J. Psychiatry 1972;120:245-58. 6. Blumer D, Heilbronn 1\[, The pain-prone disorder: a clinical and psychological profile. Psychosomatics 1981 ;22:395-402. 7. Engel GL. "Psychogenic "pain and the pain-prone patient. Am] Med 1959;26:899-918. 8. Blumer D. Zoricj F, Hcilbronn M, et al. Biological markers for depression in chronic pain.] Nerv Ment Dis 1982;170:425-28. 9. Turkington RW. Depression masquerading as diabetic neuropathy. JAMA 1980;243: 1147-50. 10. Hameroff SR, Cork RC, Scherer K, et aI. Doxepin effects on chronic pain, depression and plasma opioids J Clin Psychiatry 1982;43:22-6. 11. Bradley JJ. Severe localized pain associated with the depressive syndrome. Br J Psychiatry 1963;109:741-5. 12. Fishbain Da, Goldberg M, Meagher BR, et aI. Male and female chronic pain patients categorized by DSl\I-III psychiatric diagnostic criteria. Pain 1986;26: 181-97. 13. France RD, Houpt JL, Skott A, et aI. Depression as a psychopathological disorder in chronic low back pain patients. J Psychosom Res 1986;30: 127-33. 236 14. France RD, Krishnan KRR. The dexamethasone suppression test as a biologic marker of depression in chronic pain. Pain 1985;21 :49-55. 15. AtkinsonJN, Kremer EF, Risch SC, et al. Neuroendocrine function and endogenous opioid peptide systems in chronic pain. Psychosomatics 1983;24:899-913. 16. McDonald-Scott WA. The relief of pain with an antidepressant in arthritis. The Practitioner 1969;202:802-7. 17. Gringas 1\1. 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