title: Correlation of psychological and physical symptoms with chronically elevated cytokine levels associated with a common immune dysregulation.
abstract: BACKGROUND
  Chronically elevated levels of proinflammatory cytokines are associated with inflammatory diseases and psychological symptoms of depression and tiredness.
  
  
  OBJECTIVE
  To test the prediction that, in a healthy population without medically diagnosed diseases, psychological symptoms (depression and tiredness) associated with proinflammatory cytokines correlate with physical symptoms associated with inflammatory disease.
  
  
  METHODS
  A total of 1,143 women between 45 and 65 years old completed a health complaint checklist containing 11 target symptoms (5 related to allergy, 4 to gastrointestinal symptoms, and 2 to pain), 7 control symptoms or health complaints, and 2 psychological symptoms (depression and tiredness). They also completed a menopausal quality-of-life questionnaire; to compensate for response bias, we removed variance attributable to quality of life.
  
  
  RESULTS
  The partial correlations show that tiredness (but not depression) correlated with 9 of the 11 target symptoms (P < .001) but with 0 of the 7 control symptoms or complaints. Symptoms of both the specific and the systemic components of inflammatory disease are correlated in a healthy population.
  
  
  CONCLUSIONS
  Immune dysregulation may explain the existence and covariation of psychological and physical symptoms in the healthy population, including people with medically unexplained symptoms.
authors.affiliation: School of Psychology, University of Plymouth, Plymouth, England.
authors.forename: Ben
authors.initials: B
authors.lastname: Whalley
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Jacobs
authors.forename: Michael E
authors.initials: ME
authors.lastname: Hyland
mesh_terms: D001168:Arthritis / Q000209:etiology / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism*; D003863:Depression / Q000209:etiology* / Q000378:metabolism / Q000523:psychology; D005260:Female; D005767:Gastrointestinal Diseases / Q000209:etiology / Q000378:metabolism; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology / Q000378:metabolism; D007154:Immune System Diseases / Q000150:complications* / Q000378:metabolism; D007249:Inflammation / Q000209:etiology / Q000378:metabolism; D005222:Mental Fatigue / Q000209:etiology* / Q000378:metabolism / Q000523:psychology; D008875:Middle Aged; D011788:Quality of Life; D011795:Surveys and Questionnaires
chemical_list: D016207:Cytokines