Eastern European adolescents used to drink less than their counterparts in Western Europe and North America, but over the past decade, they've been getting drunk increasingly often, according to a new study looking at nearly 80,000 15-year-olds in 23 countries.

At the same time, Western teens -- especially boys -- are drinking less, Dr. Emmanuel Kuntsche of Addiction Info Switzerland, Research Institute, in Lausanne and his colleagues found. But girls, particularly in Eastern Europe, are drinking more.

For many years, the researchers note, social control of leisure time and lack of alcohol marketing behind the Iron Curtain seemed to keep adolescent drunkenness down. But in the 1990s, after the fall of the Berlin Wall, increasingly aggressive marketing of alcohol likely helped contribute to an increase in adolescent alcohol use during that decade.

In some Western countries, alcohol use by teen girls has been on the rise, possibly owing to changes in gender roles, the researchers add in the Archives of Pediatrics & Adolescent Medicine.

To look at both gender and East-West patterns of alcohol use among adolescents in more recent years, the researchers looked at surveys done at high schools in 1997/1998 and 2005/2006, of 77,586 adolescents in all.

In all seven Eastern European countries participating in the study, the number of times study participants reported ever having gotten drunk rose by about 40 percent (from about 2 to about 3 times for boys, and from about 1 time to 2 times for girls).

But in the 14 Western European and North American countries in the study, the average frequency of drunkenness decreased by 25 percent, from about 3 to about 2.5 for boys, and from 2.5 to 2 among girls. While gender differences narrowed overall, in most countries, except for Greenland, Norway, and the UK, boys had still gotten drunk more often than girls.

Taken together, the findings are consistent with the hypothesis that in the 8-year period of the study, a cultural convergence and a gender convergence in adolescent drunkenness occurred across countries and subgroups within countries, and adolescents became more uniform in terms of how often they drank to excess, Dr. Kuntsche and colleagues say.

The researchers suggest that the increase in alcohol marketing targeting young people is likely the most important factor behind the increase in drunkenness among Eastern European adolescents. Global marketing appears to have succeeded in increasing excessive alcohol consumption among adolescents in Eastern Europe, they write.

At the same time, they suggest, the saturation of alcohol advertising in the West may have made drinking seem conformist and traditional.

Based on the findings, the researchers say, Eastern European countries should emphasize public health approaches to discourage drunkenness, for example increasing taxes on alcohol and restricting alcohol advertising, while in the West strategies for further reducing drinking could include promoting leisure time activities that don't involve alcohol.

The gender convergence, they add, implies that prevention policy should be less exclusively focused on male adolescents.