title: Genetic structure of personality factors and bipolar disorder in families segregating bipolar disorder.
abstract: BACKGROUND
  Bipolar disorder (BPD) has been associated with variations in personality dimensions, but the nature of this relationship has been unclear. In this study, the heritabilities of BPD and the Big Five personality factors and the genetic correlations between BPD and personality factors are reported.
  
  
  METHODS
  The participants in this study were 1073 individuals from 172 families of Mexican or Central American ancestry. Heritabilities and genetic correlations were calculated under a polygenic model using the maximum-likelihood method of obtaining variance components implemented in the SOLAR software package.
  
  
  RESULTS
  Heritabilities of 0.49, 0.43, and 0.43 were found for the narrowest phenotype (schizoaffective bipolar and bipolar I), the intermediate phenotype (schizoaffective bipolar, bipolar I, and bipolar II), and the broadest phenotype (schizoaffective bipolar, bipolar I, bipolar II, and recurrent depression), respectively. For the Big Five personality factors, heritabilities were 0.25 for agreeableness, 0.24 for conscientiousness, 0.24 for extraversion, 0.23 for neuroticism, and 0.32 for openness to experience. For the narrowest phenotype, a significant negative correlation (-0.32) with extraversion was found. For the broadest phenotype, negative correlations were found for agreeableness (-0.35), conscientiousness (-0.39), and extraversion (-0.44). A positive correlation (0.37) was found with neuroticism.
  
  
  CONCLUSIONS
  It is not possible to determine whether aspects of personality are factors in the development of bipolar disorder or vice versa. The short form of the NEO does not provide the ability to examine in detail which facets of extraversion are most closely related to bipolar disorder or to compare our results with studies that have used the long version of the scale.
  
  
  CONCLUSIONS
  This study establishes a partial genetic basis for the Big Five personality factors in this set of families, while the environmental variances demonstrate that non-genetic factors are also important in their influence on bipolar and personality phenotypes. BPD may be most associated with decreased extraversion (less interaction with one's surroundings) because patients spend more time in depressive than manic states.
authors: Department of Biological Sciences and Center for Excellence in Neuroscience, Texas Tech University Health Science Center, Paul L. Foster School of Medicine, El Paso, TX, United States. liz.hare@ttuhsc.edu
authors: Elizabeth
authors: E
authors: Hare
authors: Javier
authors: J
authors: Contreras
authors: Henriette
authors: H
authors: Raventos
authors: Deborah
authors: D
authors: Flores
authors: Alvaro
authors: A
authors: Jerez
authors: Humberto
authors: H
authors: Nicolini
authors: Alfonso
authors: A
authors: Ontiveros
authors: Laura
authors: L
authors: Almasy
authors: Michael
authors: M
authors: Escamilla
mesh_terms: D001714:Bipolar Disorder / Q000235:genetics* / Q000523:psychology; D005190:Family / Q000523:psychology*; D006801:Humans; D010551:Personality / Q000235:genetics*; D010552:Personality Assessment