title: Heritability of level of response and association with recent drinking history in nonalcohol-dependent drinkers.
abstract: BACKGROUND
  Level of response (LR) to alcohol has been shown to be associated with the risk of developing alcohol dependence and can be measured using the self-rating of the effects of alcohol (SRE) questionnaire. This study examined the heritability of the SRE-measured LR and the relationship between LR and recent alcohol drinking history (RDH) in a predominantly African American nonalcohol-dependent population.
  
  
  METHODS
  This was a sibling study of 101 social drinkers aged 21 to 35 years recruited from the Washington, DC metropolitan area. Participants were administered the SRE to assess LR and the timeline followback (TLFB) to assess RDH. The indices of SRE used were total SRE score (SRTT), early drinking SRE score (SRED), regular drinking SRE score (SRRD), and heavy drinking SRE score (SRHD). Pearson's product-moment correlation and linear regression were used to analyze SRE indices and RDH variables (quantity and drinks per drinking occasion). Heritability analysis was conducted using Sequential Oligogenic Linkage Analysis Routines (SOLAR) software with SRE indices as traits of interest.
  
  
  RESULTS
  There was a significant relationship between SRE and RDH measures. Drinks per drinking day, maximum drinks, and quantity of drinks were significantly associated with SRTT, SRHD, and SRRD (all p < 0.05). SRTT showed significant heritability (h(2) = 0.67, p = 0.025), however, the SRE subindices (SRED, SRRD, SRHD) were not significantly heritable. Analysis performed in the subset consisting of only African Americans (n = 86) showed similar trends.
  
  
  CONCLUSIONS
  LR, as measured by the SRE, is associated with RDH. The high level of heritability of the SRE total score suggests that genetics accounts for a significant proportion of the variation in the LR to alcohol in social drinkers.
authors.affiliation: Department of Pharmacology, Howard University College of Medicine, Washington, DC 20059, USA. n_kalu@howard.edu
authors.forename: Nnenna
authors.initials: N
authors.lastname: Kalu
authors.forename: Vijay A
authors.initials: VA
authors.lastname: Ramchandani
authors.forename: Vanessa
authors.initials: V
authors.lastname: Marshall
authors.forename: Denise
authors.initials: D
authors.lastname: Scott
authors.forename: Clifford
authors.initials: C
authors.lastname: Ferguson
authors.forename: Gloria
authors.initials: G
authors.lastname: Cain
authors.forename: Robert
authors.initials: R
authors.lastname: Taylor
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000235:genetics* / Q000523:psychology*; D000435:Alcoholic Intoxication / Q000235:genetics* / Q000523:psychology*; D000437:Alcoholism / Q000235:genetics* / Q000523:psychology*; D002492:Central Nervous System Depressants / Q000494:pharmacology; D015331:Cohort Studies; D000431:Ethanol / Q000494:pharmacology; D005260:Female; D006801:Humans; D008297:Male; D012647:Self-Assessment; D035781:Siblings; D011795:Surveys and Questionnaires
chemical_list: D002492:Central Nervous System Depressants; D000431:Ethanol