Background. Genetic influences on alcoholism risk
are well-documented in men, but uncertain in
women. We tested for gender differences in genetic influences on, and
risk-factors for, DSM-III-R alcohol dependence (AD).
Method. Diagnostic follow-up interviews were conducted in
1992–3 by telephone with twins from
an Australian twin panel first surveyed in 1980–82
(N=5889 respondents). Data were analysed
using logistic regression models.
Results. Significantly higher twin pair concordances were observed
in MZ compared to DZ same-sex twin pairs in women and men, even when data
were weighted to adjust for over-representation
of well-educated respondents, and for selective attrition. AD risk was
increased in younger birth
cohorts, in Catholic males or women reporting no religious affiliation,
those reporting a history
of conduct disorder or major depression and in those with high Neuroticism,
Social Non-conformity, Toughmindedness, Novelty-Seeking or (in women only)
Extraversion scores; and
decreased in ‘Other Protestants’, weekly church attenders,
and university-educated males.
Controlling for these variables, however, did not remove the significant
association with having an
alcoholic MZ co-twin, implying that much of the genetic influence on AD
unexplained. No significant gender difference in the genetic variance in
was found (64% heritability, 95% confidence interval 32–73%).
Conclusions. Genetic risk-factors play as important a role
determining AD risk in women as in
men. With the exception of certain sociocultural variables such as
religious affiliation, the same
personality, sociodemographic and axis I correlates of alcoholism risk
observed in women and men.