title: Heritability of functioning in families with schizophrenia in relation to neurocognition.
abstract: The role of daily functioning is an integral part of the schizophrenia (SZ) phenotype and deficits in this trait appear to be present in both affected persons and some unaffected relatives; hence we have examined its heritability in our cohort of African American schizophrenia families. There is now ample evidence that deficits in cognitive function can impact family members who are not themselves diagnosed with SZ; there is some, but less evidence that role function behaves likewise. We evaluate whether role function tends to "run in families" who were ascertained because they contain an African American proband diagnosed with SZ.
  
  
  METHODS
  We analyzed heritability for selected traits related to daily function, employment, living situation, marital status, and Global Assessment Scale (GAS) score; modeling age, gender, along with neurocognition and diagnosis as covariates in a family based African-American sample (N=2488 individuals including 979 probands).
  
  
  RESULTS
  Measures of role function were heritable in models including neurocognitive domains and factor analytically derived neurocognitive summary scores and demographics as covariates; the most heritable estimate was obtained from the current GAS scores (h2=0.72). Neurocognition was not a significant contributor to heritability of role function.
  
  
  CONCLUSIONS
  Commonly assessed demographic and clinical indicators of functioning are heritable with a global rating of functioning being the most heritable. Measures of neurocognition had little impact on heritability of functioning overall. The family covariance for functioning, reflected in its heritability, supports the concept that interventions at the family level, such as evidenced-based family psychoeducation may be beneficial in schizophrenia.
authors.affiliation: Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA. rsavage@uab.edu
authors.forename: R M
authors.initials: RM
authors.lastname: Savage
authors.forename: H W
authors.initials: HW
authors.lastname: Wiener
authors.forename: V
authors.initials: V
authors.lastname: Nimgaonkar
authors.forename: B
authors.initials: B
authors.lastname: Devlin
authors.forename: M E
authors.initials: ME
authors.lastname: Calkins
authors.forename: R E
authors.initials: RE
authors.lastname: Gur
authors.forename: J
authors.initials: J
authors.lastname: O'Jile
authors.forename: L D
authors.initials: LD
authors.lastname: Bradford
authors.forename: N
authors.initials: N
authors.lastname: Edwards
authors.forename: J
authors.initials: J
authors.lastname: Kwentus
authors.forename: T
authors.initials: T
authors.lastname: Allen
authors.forename: J P
authors.initials: JP
authors.lastname: McEvoy
authors.forename: H
authors.initials: H
authors.lastname: Nasrallah
authors.forename: A B
authors.initials: AB
authors.lastname: Santos
authors.forename: T
authors.initials: T
authors.lastname: Aduroja
authors.forename: A
authors.initials: A
authors.lastname: Lahti
authors.forename: R S
authors.initials: RS
authors.lastname: May
authors.forename: L
authors.initials: L
authors.lastname: Montgomery-Barefield
authors.forename: R C P
authors.initials: RC
authors.lastname: Go
mesh_terms: D000203:Activities of Daily Living; D000293:Adolescent; D000328:Adult; D001741:Black or African American; D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000209:etiology* / Q000235:genetics; D004651:Employment; D005163:Factor Analysis, Statistical; D005192:Family Health; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010641:Phenotype; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000150:complications* / Q000235:genetics*; D012565:Schizophrenic Psychology; D012720:Severity of Illness Index; D055815:Young Adult