A 13-year decline in illicit drug use has halted as Americans are becoming less concerned about the hazards of drugs, say federal researchers, suggesting to some experts that the country's drug problem might be on the brink of worsening.
In an annual survey of households across the country, researchers from the Department of Health and Human Services said yesterday there were already indications of increased drug use in two age groups: teen-agers and those 35 and older.
The survey, by the Substance Abuse and Mental Health Services Administration, consisting of more than 26,000 face-to-face interviews, found that the total number of Americans who used drugs in 1993 had leveled off at 24.4 million, about the same as in 1992, from a high of 35.7 million in 1985.
But it also reported that there had been essentially no change since 1985 in the number of hard-core or heavy drug users, who are the people consuming the bulk of the 300 tons of cocaine sold each year and are responsible for most of the drug-related crime and violence. The survey had a margin of error of less than one percentage point, plus or minus.
The survey estimates that there are at least half a million heavy cocaine users, but government officials say the number may be four times as high because the survey does not reach many of the heaviest drug-using groups.
It also does not reflect the increase in the use of heroin that many experts have been reporting.
The survey indicated that 7.5 million Americans above the age of 35 used drugs during 1993, compared with about 6 million in 1992 and 7.4 million in 1991. In 1993, 2.1 million teen-agers reported using marijuana, compared with 1.7 million the previous year.
Earlier studies of teen-agers' drug habits, by University of Michigan researchers, have shown rising use of marijuana, LSD and prescription stimulants, as well as an increase in the sniffing of fumes from household products like paint thinner and glue.
The researchers said the survey results in many age and drug categories also suggested that the fear of drugs was diminishing.
"We've got things to worry about," said Richard Bonnette, the president and chief executive officer of the Partnership for a Drug Free America, a coalition of publishing, broadcasting and advertising organizations that produce more than $300 million worth of anti-drug advertisements last year.
Mr. Bonnette and other drug experts said that with many people beginning to think of drugs as less dangerous, their use was likely to begin rising.
"This is very troubling," said Dr. Lee Brown, the director of the White House Office on Drug Control Policy. "What we're looking at is a potential problem with another generation experiencing a drug epidemic."
Some drug experts interviewed yesterday suggested that responsibility for the changing situation lay with President Clinton's lack of leadership on the issue.
But Dr. Donna Shalala, the secretary of Health and Human Services, insisted that Mr. Clinton "has shown an unwaivering commitment to stemming drug abuse and its many tragic consequences."