13 percent had at least one serious problem related to underage drinking in the past year
6 percent had built up tolerance to the effects of alcohol
3 percent reported psychological problems related to their drinking
1 percent reported health problems related to their drinking

39 percent had at least one serious problem related to drinking in the past year
18 percent had built up tolerance to the effects of alcohol
8 percent reported psychological problems related to their drinking
4 percent reported health problems related to their drinking

Youth, ages 12-17, who drank heavily (5 or more drinks on 5 or more occasions in the past month):

77 percent had at least one serious problem related to underage drinking in the past year
63 percent had built up tolerance to the effects of alcohol
20 percent reported psychological problems related to their drinking
12 percent reported health problems related to their drinking

Young adults, ages 18-20, who drank heavily (5 or more drinks on 5 or more occasions in the past month):

66 percent drove under the influence of alcohol in the past year
42 percent often drove or rode without wearing a seat belt

Young adults, ages 12-20, rates of alcohol use in 1998:

Among youth ages 12-20, the rates of alcohol use were highest among those 18-20, among whites, male and among those living in the North Central region of the United States. The lowest rates of use were among blacks, females, and youth living in large metropolitan areas.

The rates of current, binge, and heavy alcohol use did not change significantly between 1994-1998. Rates were 30.6 percent, 15.2 percent, and 6.9 percent, respectively, for current, binge, and heavy use.