Subjective intoxication in response to alcohol challenge: heritability and covariation with personality, breath alcohol level, and drinking history.
BACKGROUND
Numerous studies have identified differences in subjective response to alcohol in subjects differentiated by family history of alcoholism. Results suggest that genetic influences on individual variation in subjective response to alcohol may be a mechanism for genetic effects on alcohol problems. However, direct evidence for genetic effects on subjective response to alcohol is very limited.


METHODS
In a sample of 99 adult twin pairs, we studied genetic influences on subjective intoxication after alcohol challenge. The twins ingested a standard dose of ethanol (0.70 g/kg for men/0.65 g/kg for women), and two measures of subjective response to alcohol were assessed.


RESULTS
Genetic effects on variation in subjective intoxication reported 1 hr after drinking were significant and substantial: heritability was 0.60 for a 22-item scale and 0.48 for a brief 2-item measure. Self-report measures of neuroticism, psychasthenia, hostility, and family problems shared significant genetic covariation with subjective intoxication. Achieved breath alcohol level, rate of change in breath alcohol on the descending limb, and individual drinking history all shared familial variation with subjective intoxication. No significant genetic effects for subjective intoxication were found 2 hr after drinking, but familial influences remained present, and many of the same personality, drinking history, and breath alcohol variables were predictive of intoxication.


CONCLUSIONS
Subjective response to alcohol is heritable, and genetic effects on subjective intoxication are partly shared with genetic effects on personality.
Viken
Richard J
RJ
Department of Psychology, Purdue School of Science, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA. viken@indiana.edu
Rose
Richard J
RJ
Morzorati
Sandra L
SL
Christian
Joe C
JC
Li
Ting-Kai
TK
D000328:Adult; D000428:Alcohol Drinking; D000435:Alcoholic Intoxication / Q000175:diagnosis / Q000235:genetics* / Q000523:psychology*; D001944:Breath Tests; D004200:Diseases in Twins; D000431:Ethanol / Q000008:administration & dosage* / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010551:Personality / Q000235:genetics*; D012677:Sensation; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics
D000431:Ethanol