Alcohol misuse and relationship breakdown: Findings from a longitudinal birth cohort

Descriptively, male-female differences in alcohol consumption and alcohol use disorders appear to have decreased in birth cohorts reaching adulthood since the 1970s compared to earlier birth cohorts. However, such birth cohort effects on gender differences have never been statistically tested in nationally representative data. The aim of this study was to test the hypothesis that gender differences in alcohol consumption, abuse, and dependence are decreasing over time. Face-to-face survey conducted in the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions among those aged <90 (N=42,693). Birth cohort was divided into four categories: 1913-1932, 1933-1949, 1950-1967, 1968-1984. Outcomes included lifetime largest drinks, frequent binge drinking, DSM-IV defined alcohol abuse, and alcohol dependence, measured with the Alcohol Use Disorder and Associated Disabilities Interview Schedule (AUDADIS-IV). Birth cohort and gender interacted significantly in predicting lifetime largest drinks (F=27.6, [d.f.=3], p<0.0001), frequent binge drinking (F=40.0, [d.f.=3], p<0.0001), alcohol abuse (F=62.0, [d.f.=3], p<0.0001) and alcohol dependence (F=15.3, [d.f.=3], p<0.0001). Cohort-specific ORs indicated monotonic decreases in the gender ratio in more recent birth cohorts for all outcomes. These results suggest that gender differences in the prevalence of all four outcomes are decreasing in younger age cohorts. While these changes are consistent with a cohort effect, the possibility of age and period effects cannot be ruled out but suggest important avenues for more specific hypothesis testing. Further, women in younger cohorts may be in need of new targeted prevention and intervention efforts.

To examine the associations between the frequency of cannabis use and the use of other illicit drugs. A 25-year longitudinal study of the health, development and adjustment of a birth cohort of 1,265 New Zealand children. Annual assessments of the frequency of cannabis use were obtained for the period 14-25 years, together with measures of the use of other illicit drugs from the same time period. The frequency of cannabis use was associated significantly with the use of other illicit drugs, other illicit drug abuse/dependence and the use of a diversity of other drugs. This association was found to be particularly strong during adolescence but declined rapidly as age increased. Statistical control for confounding by both fixed and time dynamic factors using random- and fixed-effects regression models reduced the strength of association between frequency of cannabis use and other illicit drug use, but a strong association between frequency of cannabis use and other illicit drug use remained even after control for non-observed and time-dynamic sources of confounding. Regular or heavy cannabis use was associated with an increased risk of using other illicit drugs, abusing or becoming dependent upon other illicit drugs, and using a wider variety of other illicit drugs. The risks of use, abuse/dependence, and use of a diversity of other drugs declined with increasing age. The findings may support a general causal model such as the cannabis gateway hypothesis, but the actual causal mechanisms underlying such a gateway, and the extent to which these causal mechanisms are direct or indirect, remain unclear.