The researchers examined two large, national surveys and compared lifetime prevalence rates from the same age groups and demographics, while simultaneously controlling for age-related factors.

Richard A. Grucza, an epidemiologist at Washington University School of Medicine in St. Louis said that by looking at two cross-sectional surveys that asked the same questions in the same manner but were conducted 10 years apart, the researchers were able to compare, those age 30 to 40 years in 2001 with those 30 to 40 in 1991.

"Essentially, this allowed us to correct for the effects of age on reporting," Grucza said in a statement.

The study, published in Alcoholism: Clinical & Experimental Research, found that for women born after World War II, there are lower levels of abstaining from alcohol and higher levels of alcohol dependence but there was no significant tendency for more recently born men to have lower levels of abstention or higher levels of alcohol dependence.

Grucza said the findings are probably due to higher levels of alcohol problems among women, while men have been more or less steady in their levels of dependence.