title: Covariation, co-occurrence and epiphenomenal correlation of empirically based syndromes in children and adolescents.
abstract: BACKGROUND
  This paper determines the co-occurrence and correlations of different problem behaviours in children and adolescents in German clinical and general population samples.
  
  
  METHODS
  The 2 samples were matched by age and gender (each sample n = 1,760). Including both categorical and dimensional models, rates of co-occurrence, relative risks, odds ratios and Pearson correlations were calculated.
  
  
  RESULTS
  The bidirectional comorbidity rates ranged from 7.3 to 34.3% (epidemiological sample) and from 22.5 to 54.8% (clinical sample). Most correlations between syndrome scales show medium or large effects. Many can be identified as 'epiphenomenal'; partial correlations from each pair, excluding influences of other syndromes, are much lower.
  
  
  CONCLUSIONS
  This study shows the cross-cultural generalizability of comorbidity rates. The epiphenomenal nature of some comorbidities warrants future attention.
authors.affiliation: Department of Child and Adolescent Psychiatry, University of Cologne, Cologne, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Döpfner
authors.forename: Julia
authors.initials: J
authors.lastname: Plueck
authors.forename: Gerd
authors.initials: G
authors.lastname: Lehmkuhl
authors.forename: Michael
authors.initials: M
authors.lastname: Huss
authors.forename: Klaus
authors.initials: K
authors.lastname: Lenz
authors.forename: Ulrike
authors.initials: U
authors.lastname: Lehmkuhl
authors.forename: Fritz
authors.initials: F
authors.lastname: Poustka
authors.forename: Klaus
authors.initials: K
authors.lastname: Schmeck
authors.forename: Joerg M
authors.initials: JM
authors.lastname: Fegert
mesh_terms: D000293:Adolescent; D002648:Child; D002653:Child Behavior Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology*; D002675:Child, Preschool; D015897:Comorbidity; D039721:Diagnostic and Statistical Manual of Mental Disorders; D036262:Empirical Research; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology*; D011795:Surveys and Questionnaires; D013577:Syndrome