Alcoholic typology and season of birth

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 Abu se Prevention and Control Program from 1986 through 1990. Method: Subjects were enrolled for treatment of alcoholism or alcohol-relat ed problems, and were analyzed for half year of birth. Groupings by age and gender, consistent with current theories of alcoholic typology, were compa red, by means of chi-square tests, and by comparisons of two rates or propo rtions. 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 t he normal circannual birth pattern, but in opposite directions. Conclusions: The findings support the differentiation of types of alcoholic s by age, which is a characteristic of Cloninger's classification, suggesti ng a biological, pre-natal factor.