title: Predictions and associations of fatigue syndromes and mood disorders that occur after infectious mononucleosis.
abstract: BACKGROUND
  Certain infections can trigger chronic fatigue syndromes (CFS) in a minority of people infected, but the reason is unknown. We describe some factors that predict or are associated with prolonged fatigue after infectious mononucleosis and contrast these factors with those that predicted mood disorders after the same infection.
  
  
  METHODS
  We prospectively studied a cohort of 250 primary-care patients with infectious mononucleosis or ordinary upper-respiratory-tract infections until 6 months after clinical onset. We sought predictors of both acute and chronic fatigue syndromes and mood disorders from clinical, laboratory, and psychosocial measures.
  
  
  RESULTS
  An empirically defined fatigue syndrome 6 months after onset, which excluded comorbid psychiatric disorders, was most reliably predicted by a positive Monospot test at onset (odds ratio 2.1 [95% CI 1.4-3.3]) and lower physical fitness (0.35 [0.15-0.8]). Cervical lymphadenopathy and initial bed rest were associated with, or predicted, a fatigue syndrome up to 2 months after onset. By contrast, mood disorders were predicted by a premorbid psychiatric history (2.3 [1.4-3.9]), an emotional personality score (1.21 [1.11-1.35]), and social adversity (1.7 [1.0-2.9]). Definitions of CFS that included comorbid mood disorders were predicted by a mixture of those factors that predicted either the empirically defined fatigue syndrome or mood disorders.
  
  
  CONCLUSIONS
  The predictors of a prolonged fatigue syndrome after an infection differ with both definition and time, depending particularly on the presence or absence of comorbid mood disorders. The particular infection and its consequent immune reaction may have an early role, but physical deconditioning may also be important. By contrast, mood disorders are predicted by factors that predict mood disorders in general.
authors.affiliation: Department of Psychological Medicine, St Bartholomew's and the Royal London School of Medicine and Dentistry, London, UK. P.D. White@qmul.ac.uk
authors.forename: P D
authors.initials: PD
authors.lastname: White
authors.forename: J M
authors.initials: JM
authors.lastname: Thomas
authors.forename: H O
authors.initials: HO
authors.lastname: Kangro
authors.forename: W D
authors.initials: WD
authors.lastname: Bruce-Jones
authors.forename: J
authors.initials: J
authors.lastname: Amess
authors.forename: D H
authors.initials: DH
authors.lastname: Crawford
authors.forename: S A
authors.initials: SA
authors.lastname: Grover
authors.forename: A W
authors.initials: AW
authors.lastname: Clare
mesh_terms: D016009:Chi-Square Distribution; D015673:Fatigue Syndrome, Chronic / Q000209:etiology* / Q000523:psychology; D005260:Female; D006801:Humans; D007244:Infectious Mononucleosis / Q000150:complications* / Q000175:diagnosis / Q000523:psychology; D008297:Male; D019964:Mood Disorders / Q000209:etiology* / Q000523:psychology; D010809:Physical Fitness; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires