title: Latent class analysis shows strong heritability of the child behavior checklist-juvenile bipolar phenotype.
abstract: BACKGROUND
  The Child Behavior Checklist (CBCL) has been used to provide a quantitative description of childhood bipolar disorder (BPAD). Many have reported that children in the clinical range on the Attention Problems (AP), Aggressive Behavior (AGG), and Anxious-Depressed (A/D) syndromes simultaneously are more likely to meet the criteria for childhood BPAD. The purpose of this study was to determine if Latent Class Analysis (LCA) could identify heritable phenotypes representing the CBCL-Juvenile Bipolar (CBCL-JBD) profile and whether this phenotype demonstrates increased frequency of suicidal endorsement.
  
  
  METHODS
  The CBCL data were received by survey of mothers of twins in two large twin samples, the Netherlands Twin Registry. The setting for the study was the general community twin sample. Participants included 6246 10-year-old Dutch twins from the Netherlands Twin Registry. The main outcome measure consisted of the LCA on the items comprising the AP, AGG, and A/D subscales and means from the suicidal items #18 and #91 within classes.
  
  
  RESULTS
  A 7 class model fit best for girls and an 8 class fit best for boys. The most common class for boys or girls was one with no symptoms. The CBCL-JBD phenotype was the least common--about 4%-5% of the boys and girls. This class was the only one that had significant elevations on the suicidal items of the CBCL. Gender differences were present across latent classes with girls showing no aggression without the CBCL-JBD phenotype and rarely showing attention problems in isolation. Evidence of high heritability of these latent classes was found with odds ratios.
  
  
  CONCLUSIONS
  In a general population sample, LCA identifies a CBCL-JBD phenotype latent class that is associated with high rates of suicidality, is highly heritable, and speaks to the comorbidity between attention problems, aggressive behavior, and anxious/depression in children.
authors.affiliation: Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Robert R
authors.initials: RR
authors.lastname: Althoff
authors.forename: David C
authors.initials: DC
authors.lastname: Rettew
authors.forename: Stephen V
authors.initials: SV
authors.lastname: Faraone
authors.forename: Dorret I
authors.initials: DI
authors.lastname: Boomsma
authors.forename: James J
authors.initials: JJ
authors.lastname: Hudziak
mesh_terms: D000374:Aggression / Q000502:physiology; D001007:Anxiety / Q000503:physiopathology; D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology; D001714:Bipolar Disorder / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D004200:Diseases in Twins; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D016017:Odds Ratio; D010555:Personality Inventory / Q000706:statistics & numerical data*; D011569:Psychiatric Status Rating Scales; D012189:Retrospective Studies; D012737:Sex Factors; D013405:Suicide; D018433:Twin Studies as Topic