Overall, drug use among Americans of all ages remained level, but use among young adults continued its steady rise, according to the annual household survey of 25,500 people, ages 12 and up.
All told, 78 million Americans had tried illegal drugs at some point in their lives. Marijuana remained far and away the most popular drug, but 41.3 million Americans also had tried heroin, cocaine or some other illegal drug, the survey said.
Of them, 13.6 million were current users, about half what it was at its 1979 peak.
The National Household Survey on Drug Abuse also measured cigarette smoking and found it down to 27.7 percent overall, the lowest rate recorded. But smoking remained steady among teens and continued to rise among young adults. Cigar use edged up.
In a written statement, reports CBS News White House Correspondent Mark Knoller, the president hailed some of the findings, saying the nation has turned an important corner on youth drug use.
The president called it "encouraging news [that] shows more young people are getting the message that drugs are wrong, illegal and can kill you.
"While these results give us reason to be optimistic, we can not let up on our efforts," the statement said.
The portion of teens saying they had ever used drugs was also down, from 18.8 percent in 1997 to 16.4 percent last year.
The declines were driven by older teens - ages 16 and 17 - with the percentage having used drugs in the past year falling from 30.7 percent to 26.8 percent.
Marijuana, the most popular drug, tends to fuel the overall rate, though its usage has fluctuated over the past few years. Last year, it fell to 8.3 percent among teens, back to its 1995 level and still significantly higher than the 3.4 percent recorded in 1992.
Overall, teen drug use rose through much of the 1990s and is still much higher than it was in 1991 and 1992. Researchers attribute the rise to a relaxing of the intense prevention efforts of the 1980s.
Wednesday's news was not as good for young adults aged 18 to 25. The survey found 16.1 percent of them were "current users," meaning they had used drugs in the past month. That rate has been gradually ising, up from 13.3 percent in 1994.
In particular, cocaine use was up, from 1.2 percent in 1997 to 2 percent in 1998.
Officials suspect that the rising statistics relate to this particular group, the same people who were more likely to use drugs when they were teen-agers and who have now become young adults.
Overall, drug use among all ages remained level in 1998, with 13.6 million current users. That's 6.2 percent of the population, statistically unchanged from 6.4 percent in 1997.
But the rates have increased among minority groups. The percent of blacks currently using drugs jumped from 5.8 percent in 1993 to 8.2 percent last year. Hispanics saw a similar rise, from 4.4 percent to 6.1 percent over those five years.
Overall use of marijuana was steady in 1998, with about 11 million Americans smoking it in the month preceding the survey - nearly twice as many users as cocaine, heroine, LSD and other drugs combined.
You can see a summary of the 1998 National Household Survey on Drug Abuse on the Internet.