title: Alcoholic typology and season of birth.
abstract: OBJECTIVE
  This study analyzed the half years of birth of a large (n = 113,276) population of alcoholic patients in the U.S. Army Alcohol and Drug Abuse Prevention and Control Program from 1986 through 1990.
  
  
  METHODS
  Subjects were enrolled for treatment of alcoholism or alcohol-related problems, and were analyzed for half year of birth. Groupings by age and gender, consistent with current theories of alcoholic typology, were compared, by means of chi-square tests, and by comparisons of two rates or proportions.
  
  
  RESULTS
  The 17-21 year old and the 22-39 year old age groups differed by 5.1% in regard to half year of birth (chi-square = 260.317, p < 0.001, 95% CI:4.481 to 5.725, odds ratio: 1.23). Both groups differed significantly from the normal circannual birth pattern, but in opposite directions.
  
  
  CONCLUSIONS
  The findings support the differentiation of types of alcoholics by age, which is a characteristic of Cloninger's classification, suggesting a biological, pre-natal factor.
authors.affiliation: Department of Psychiatry, Brooke Army Medical Center, Fort Sam Houston, TX 78234, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Levine
authors.forename: B E
authors.initials: BE
authors.lastname: Wojcik
mesh_terms: D000293:Adolescent; D000328:Adult; D000437:Alcoholism / Q000453:epidemiology* / Q000523:psychology / Q000534:rehabilitation; D001723:Birth Rate; D005260:Female; D006801:Humans; D008297:Male; D008889:Military Personnel / Q000523:psychology; D012621:Seasons; D013997:Time Factors; D014481:United States / Q000453:epidemiology