title: [Early alcohol initiation and increased adult alcohol consumption: cause or indicator?].
abstract: BACKGROUND
  Early alcohol initiation is strongly associated with increased alcohol consumption and alcohol abuse/dependence in adulthood. The mechanisms that underlie this association are unclear.
  
  
  OBJECTIVE
  To examine whether there is a causal link between early alcohol initiation and later alcohol consumption.
  
  
  METHODS
  Survey data were collected from twin pairs (age range 18-80) included in the Netherlands Twin Register (NTR). A discordant twin design was used to examine the origin of the link between early alcohol initiation and adult alcohol consumption. Within monozygotic pairs (82-143 pairs), twins who started drinking early were compared to their brother/sister who started drinking later, on frequency of alcohol use, weekly alcohol consumption, number of alcohol intoxications, excessive drinking, alcohol abuse/-dependence, and hazardous drinking. By drawing comparisons within monozygotic pairs, we were able to control for the effects of genes/shared environment. Additional analyses examined the effects of age, sex, and in-/exclusion of lifelong abstainers.
  
  
  RESULTS
  Within monozygotic twin pairs, the twin who had started drinking early did not differ significantly from his/her brother/sister with respect to future alcohol consumption. Results were independent of age, sex, and in-/exclusion of lifelong abstainers.
  
  
  CONCLUSIONS
  Early alcohol initiation did not have significant causal effects on subsequent alcohol consumption in adulthood and may be an indicator of a predisposition for alcohol consumption. Campaigns aimed at raising the minimum age for alcohol initiation will possibly have only a limited effect on adult alcohol consumption.
authors: Vrije Universiteit, Amsterdam, The Netherlands. L.M.Geels@vu.nl
authors: L M
authors: LM
authors: Geels
authors: J M
authors: JM
authors: Vink
authors: J H D A
authors: JH
authors: van Beek
authors: G
authors: G
authors: Willemsen
authors: M
authors: M
authors: Bartels
authors: D I
authors: DI
authors: Boomsma
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000453:epidemiology*; D000437:Alcoholism / Q000453:epidemiology / Q000209:etiology / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D012307:Risk Factors; D012931:Social Environment; D014430:Twins, Monozygotic; D055815:Young Adult