Many young adults experience their spring vacations through an alcoholic haze, a new national survey by the American Medical Association shows. Forty percent of the 18-to-30-year-olds surveyed admit they become mentally and physically tipsy from booze. College graduates are found more likely to drink, but those who completed only high school are most likely to drink heavily, the survey, published in Chicago, found. One in five of the 800 respondents said they binge drink, defined as consuming five or more drinks by males (four by females) during a single session. Young adults in the northeast United States are almost twice as likely to binge drink as those in any other region, while in the Pacific Northwest almost three-fourths of young adults do not binge.