title: The search for genetic risk factors associated with suicidal behavior.
abstract: BACKGROUND
  Suicide and suicidal behavior are prevalent among individuals with psychiatric disorders, including alcohol dependence. A genome screen was performed in multiplex alcohol dependent families ascertained as part of the Collaborative Study on the Genetics of Alcoholism to identify chromosomal regions of interest related to two types of suicidal behavior: suicide attempts and suicidality.
  
  
  METHODS
  Sibling pair analyses were used to conduct linkage analyses using both qualitative and quantitative suicide-related phenotypes. The qualitative trait of "suicide attempts" was examined using 59 affected sibling pairs. The quantitative trait of "suicidality" was examined using all possible 1366 sibling pairs and 705 independent sibling pairs.
  
  
  RESULTS
  For the qualitative phenotype suicide attempts, chromosome 2 yielded a maximum lod score of 4.2. For the quantitative suicidality index, a maximum lod score of 1.8 was observed on chromosome 3, and a lod score of 1.5 was found on chromosome 1.
  
  
  CONCLUSIONS
  This study represents the first genome-wide scan of suicidal behavior. Significant evidence of linkage was found on chromosome 2 for the phenotype suicide attempts, the same chromosomal region previously reported to be linked to alcohol dependence in this sample. This finding does not seem to be due solely to an association between suicide and alcohol dependence. There was more modest evidence of linkage to chromosomes 1 and 3 for suicidality; however, these findings did not reach statistical significance. There was no overlap in findings for these two phenotypes of suicidal behavior.
authors.affiliation: Department of Psychiatry, University of Connecticut School of Medicine, Farmington, Connecticut, USA. hesselb@psychiatry.uuchc.edu
authors.forename: Victor
authors.initials: V
authors.lastname: Hesselbrock
authors.forename: Danielle
authors.initials: D
authors.lastname: Dick
authors.forename: Michie
authors.initials: M
authors.lastname: Hesselbrock
authors.forename: Tatiana
authors.initials: T
authors.lastname: Foroud
authors.forename: Marc
authors.initials: M
authors.lastname: Schuckit
authors.forename: Howard
authors.initials: H
authors.lastname: Edenberg
authors.forename: Kathy
authors.initials: K
authors.lastname: Bucholz
authors.forename: John
authors.initials: J
authors.lastname: Kramer
authors.forename: Theodore
authors.initials: T
authors.lastname: Reich
authors.forename: Alison
authors.initials: A
authors.lastname: Goate
authors.forename: Laura
authors.initials: L
authors.lastname: Bierut
authors.forename: John P
authors.initials: JP
authors.lastname: Rice
authors.forename: John I
authors.initials: JI
authors.lastname: Nurnberger
mesh_terms: D000437:Alcoholism / Q000453:epidemiology / Q000235:genetics*; D002889:Chromosomes, Human, Pair 2 / Q000235:genetics; D005260:Female; D008040:Genetic Linkage / Q000235:genetics*; D020022:Genetic Predisposition to Disease / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D008126:Lod Score; D008297:Male; D010641:Phenotype; D012307:Risk Factors; D013405:Suicide / Q000706:statistics & numerical data