title: Longitudinal stability of the CBCL-juvenile bipolar disorder phenotype: A study in Dutch twins.
abstract: BACKGROUND
  The Child Behavior Checklist-juvenile bipolar disorder phenotype (CBCL-JBD) is a quantitative phenotype that is based on parental ratings of the behavior of the child. The phenotype is predictive of DSM-IV characterizations of BD and has been shown to be sensitive and specific. Its genetic architecture differs from that for inattentive, aggressive, or anxious-depressed syndromes. The purpose of this study is to assess the developmental stability of the CBCL-JBD phenotype across ages 7, 10, and 12 years in a large population-based twin sample and to examine its genetic architecture.
  
  
  METHODS
  Longitudinal data on Dutch mono- and dizygotic twin pairs (N = 8013 pairs) are analyzed to decompose the stability of the CBCL-JBD phenotype into genetic and environmental contributions.
  
  
  RESULTS
  Heritability of the CBCL-JBD increases with age (from 63% to 75%), whereas the effects of shared environment decrease (from 20% to 8%). The stability of the CBCL-JBD phenotype is high, with correlations between .66 and .77 across ages 7, 10, and 12 years. Genetic factors account for the majority of the stability of this phenotype. There were no sex differences in genetic architecture.
  
  
  CONCLUSIONS
  Roughly 80% of the stability in childhood CBCL-JBD is a result of additive genetic effects.
authors.affiliation: Department of Biological Psychology, Vrije Universiteit, Amsterdam, The Netherlands. dorret@psy.vu.nl
authors.forename: Dorret I
authors.initials: DI
authors.lastname: Boomsma
authors.forename: Irene
authors.initials: I
authors.lastname: Rebollo
authors.forename: Eske M
authors.initials: EM
authors.lastname: Derks
authors.forename: Toos C E M
authors.initials: TC
authors.lastname: van Beijsterveldt
authors.forename: Robert R
authors.initials: RR
authors.lastname: Althoff
authors.forename: David C
authors.initials: DC
authors.lastname: Rettew
authors.forename: James J
authors.initials: JJ
authors.lastname: Hudziak
mesh_terms: D000367:Age Factors; D001714:Bipolar Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics* / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D016001:Confidence Intervals; D004200:Diseases in Twins; D004777:Environment; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D010555:Personality Inventory; D010641:Phenotype; D011569:Psychiatric Status Rating Scales; D012044:Regression Analysis; D018433:Twin Studies as Topic; D014427:Twins