The U.S. Surgeon General in March, 2007 issued a Call to Action to stop America's 11 million current underage drinkers from using alcohol and to keep other young people from starting. Until recently, it was thought that underage drinkers were mostly boys. Now it seems that boys and girls are becoming more similar in their use of alcohol. To understand the possible reasons and implications of this trend Dr. Kimberly Williams, Clinical Neuropsychologist at the NYU Child Study Center, was interviewed for AboutOurKids.org by Dr. Anita Gurian.

What do you think this shift in boy/girl alcohol use is due to?

There are factors which effect both genders, including the huge prevalence of alcohol in American culture, more absent parents, increasing rates of stress, anxiety, and depression among youth, and access to more spending money than previous generations.

The increase in girls' use of alcohol is influenced by several factors.

Increasingly, girls age 12-17 report higher stress levels than boys. This stress is linked to interpersonal relationship distress between peers and family and worries about achievement. Furthermore, parents grossly underestimate the risks of their preteen daughters' exposures to the influence of alcohol and misjudge the seriousness of the issue.

Gender studies show that many girls strive to be "one of the boys." Drinking and partying like boys provides a false sense of liberation and empowerment. In addition, research shows that having male friends increases the risk of alcohol use; spending time with boys makes girls feel more comfortable with sensation seeking and contributes to more adult-like precocious behavior. Girls find that alcohol has a disinhibiting effect that enhances their perception of being more confident, increases social comfort, and offers feelings of being sexually alluring. Being a socially gregarious and sexually provocative partner increases female popularity in many circles.

Finally, for many college age girls, living on campus is often their first time away from home without constant supervision. Many girls take on drinking because they are separated from previous support systems and have new peers they are trying to impress.

Girls are now starting to drink at younger ages. In the 1960s only 7% of girls reported having their first drink between the ages of 10 and 14. Now nearly 25% of girls report having their first drink before age 13. Why do you think girls are starting to drink at earlier ages?

The average onset age of puberty is decreasing, and girls who experience early puberty are apt to engage in substance abuse earlier than girls who mature later. But despite the younger age at which children reach puberty, their social development has not increased, and thus ill informed decisions about drinking can result in health-damaging behaviors.

We also know that the human brain is still developing well into the 20s. It's thought that this longer developmental period contributes to characteristic adolescent behaviors, such as risk taking and poor impulse control, which frequently lead to experimentation with alcohol.

Is this part of a downward trend in general, such as the earlier age at which girls start to diet, to wear teenage-style clothing and to emulate performers such as Britney, Lindsay, and Paris?

When young girls see celebrities drinking, partying, and breaking the law, it conjures up the image that "bad girls have more fun," which incidentally is a logo for a popular brand of rum. This belief is harmful to the development of a healthy self-image, as it promotes false ideas that drinking makes you fun and sexy, and that no matter how ridiculous you act while drunk, everyone will still love and support you. The push to be sexy goes hand-in-hand with the desire to drink. Also, the trends of dieting, wearing revealing clothes, and emulating celebrities, ultimately lead to body shame, depression, eating disorders and low self-esteem.

Damage to the brain is a possible consequence of drinking; is the risk the same for boys and girls?

Women are more sensitive to alcohol-induced brain damage than men. We know that if women drink excessively, over time they experience reduction in the size of a part of the brain, called the corpus callosum, whereas alcoholic men do not. Younger girls will become intoxicated more quickly due to lower body weight and metabolism. Thus they are more susceptible to alcohol poisoning which can reach life-threatening levels of intoxication faster than males of the same age. Females dependent upon alcohol report significantly greater depression, anxiety, and other psychological problems compared to their male counterparts.

Are there other physical differences that might make girls more vulnerable to the effects of alcohol?

Females have less body fluid than males. Therefore, if a female and a male of the same size and weight drink the same amount of alcohol, the female will have a higher concentration of alcohol in her blood. Similarly, young women naturally produce less of the gastric enzyme alcohol dehydrogenase, which breaks down ethanol in the stomach, which also contributes to higher blood alcohol content than men of the same age, even with allowance for size differences.

We also know that alcoholic women do not break down fatty acids as well as alcoholic men. This leads to accumulation of fatty acids in the alcoholic woman's liver, which is why alarming rates of women develop alcoholic liver diseases, particularly cirrhosis and hepatitis, after a comparatively shorter period of heavy drinking and at a lower level of daily drinking than men.

Even in their late teens and early 20s, women who chronically abuse alcohol can get serious gastrointestinal problems such as ulcers. Women can also suffer from malnourishment because they're getting most of their calories from alcohol, not food. Women who consume more than two alcoholic drinks per day are more likely than non-drinkers to develop breast cancer, hypertension, and stroke. Finally, women who drink heavily are more likely to experience infertility and miscarriage.

Does marketing specifically target girls?

The alcohol industry knows that the best way to create lifetime heavy drinkers is to start them early. When a Georgetown University team looked at the advertising content and readership ages of popular magazines, they found that underage youths saw more alcohol advertising than did adults in 2002, and that teen girls were far more likely to be exposed to that advertising than teen boys. While underage boys saw 29 percent more beer advertising in 2002 than legal-age men, underage girls saw 68 percent more such advertising than legal women.

Critics also worry that marketers are fueling the trends by targeting younger women with "alcopops," the nickname for sweet, flavored, colored alcoholic "soda-like," beverages. Advertisers suggest that "you can drink more because it doesn't taste bad". A recent American Medical Association study of teens found alcopops most popular with 13-year-old girls, making up 29% of alcohol consumption within the group. For 15-year-old girls, wine was most popular, comprising 34% of alcohol intake, but alcopops were close behind at 26%.

Does the age at which a child starts drinking make a difference in terms of future drinking habits and does it have an impact on health?

New evidence from Duke University shows that heavy drinking during teenage years can cause irreparable brain damage and increases the risk of alcoholism. Using brain-imaging technology, they found that large doses of alcohol shut down neural receptors in the brains of adolescent rats, causing permanent damage. The evidence suggests that the same damage probably occurs in humans as well. Teens who begin drinking before age 15 are five times more likely to develop alcohol dependence than those who begin drinking after age 21.

According to a study by the National Institute of Health, girls are more swayed by peer pressure than boys. Has this been your experience?

Recently a federal study based on confidential surveys on drinking and smoking given to over 4,000 teens in junior-high schools supported this idea. A number of experts were not surprised that friends can sway girls more easily than boys. Girls go through a tremendous amount of emotional and hormonal changes as they go to seventh grade. These changes come at a time when adolescents are trying to establish their identity and gaining independence is really important. The study found that the single most important factor for girls is the behavior of their five closest friends.

Should parents of teenagers allow them to drink at home under their parents' supervision?

Frankly the trends are disturbing. Recent AMA statistics show how easily teens, especially young girls, can get alcohol supplied by legal-age adults, even parents. In a poll of teens aged 13-18, girls nearly always ranked higher than boys in obtaining alcohol. In the adult poll, about one out of four U.S. parents with children, aged 12-20 (26%), agree that teens should be able to drink at home with their parents present. Two out of three teens, aged 13-18, said it is easy to get alcohol from their homes without parents knowing about it. One third responded that it is easy to obtain alcohol from their parents. One in four teens has attended a party where minors were drinking in front of parents. The AMA warns that parents allowing underage children to drink under their supervision are under a dangerous misperception. Injuries and car accidents after such parent-hosted parties remind us that no parent can completely control the actions of intoxicated youth, during or after a party. The message children hear is that drinking illegally is okay. However new social host liability laws in states across the country are changing parents' minds. Under these laws, adults who serve or supply alcohol to persons under the age of 21 can be held liable if any of those underage persons is killed or injured.

How can parents and other significant adults in the lives of girls prevent alcohol use by girls?

Parents should start the conversation early and have it often. Age 11 is not too early to start talking with your daughter about the dangers of underage drinking. Frequent conversations with clear messages and expectation about not drinking should follow and continue throughout a girl's high school years and beyond.

Parents should also be approachable, remember to keep an open mind and try not to overreact during the discussion. It's important to seize opportunities to discuss real life situations and consequences.

Be a parent, not a friend. Share your parental values and set the rules. Make it clear that underage drinking is not okay under any circumstances. To girls who care about their appearance, it may be more beneficial to discuss the toll alcohol takes on the way they look or how it will change their physical characteristics, than to talk about far-off liver disease.

Parents also need to teach their young girls "refusal skills" and come up with alternate social interactions, such as a sports activity or a movie, where chemicals aren't involved.

It's important to supervise your daughter and know who her friends are, where they are going, and what they are doing. Encourage girls to maintain friendships with other girls who make good choices and decisions.