WASHINGTON — In what some researchers warned could be the start of a worrisome new trend, an annual federally funded survey has found “significant” increases in the use of marijuana, cocaine, LSD, inhalants and other illicit substances among eighth-graders, most of whom are 13 or 14 years old.

The annual University of Michigan survey found that 11.2 percent of eighth-graders reported trying marijuana in 1992, a full percentage-point jump over a similar sample taken the previous year.

“It’s really the first evidence of an increase in use among young people since 1986 when cocaine started to drop,” said Lloyd Johnston, principal investigator of the survey.

Among high-school seniors, use of most drugs continued a downward trend. But the survey found seniors were increasingly less likely to view experimentation or even occasional use of illicit substances as dangerous, a potential harbinger of increases in use.

Calling the findings “troublesome,” Johnston and other researchers attributed the results to a growing complacency about the problems of drug abuse combined with a lack of attention to the issue by government and the media.

After all the fanfare over the drug problem in the late 1980s, “it’s fallen into a black hole,” Johnston said.

The survey, which anonymously sampled more than 50,000 eighth-, 10th- and 12th-graders in public and private schools across the country, is widely regarded as one of the government’s chief benchmarks for measuring progress in the drug war. In recent years, when the survey has recorded striking declines in drug use across the board, its findings were released at a widely heralded Washington news conference attended by senior government officials and Cabinet members.

But Tuesday, the Department of Health and Human Services simply distributed a news release that included comments from Secretary Donna E. Shalala. Shalala said that while the survey showed “continued improvement among high-school seniors … we need to be sure that younger students are still learning the facts about drug and alcohol abuse.”

As Shalala noted, the overall findings were a mixed bag. Among the 17,000 seniors surveyed in the Class of 1992, 25.1 percent reported having tried marijuana at least once, down from a peak of 58.7 percent in 1982.

Only 6.1 reported ever trying cocaine, down from a peak of 17.3 percent in 1975 when the survey of high-school seniors began.

Even use of LSD, a hallucinogen that some drug specialists had warned last year was on the brink of a comeback, showed no signs of any increases with 8.6 percent reported having tried the drug at least once among the Class of 1992, virtually unchanged from the year before.

But the findings among eighth-graders were described by researchers as more disturbing.

Johnston’s researchers began polling eighth-graders only in 1991, so the increases reported Tuesday covering student responses last year could not be described as a long-term trend.

Nonetheless, the 1992 findings found modest but “statistically significant” increases in eighth-grade use of virtually every drug: 10.8 percent reported having tried stimulants such as amphetamines, up from 10.3 percent in the previous year’s sample; 4.1 percent reported using tranquilizers, up from 3.8 percent the previous year; and 2.9 percent reported having used cocaine, up from 2.3 percent the previous year.

The survey also found some reductions in alcohol use but little change in cigarette smoking, viewed by some officials as the most serious threat to public health. For example, 27.8 percent of 12th-graders reported smoking cigarettes in the previous month.

Herb Kleber, the former deputy director of the White House Office of National Drug Control Policy under President Bush, said Tuesday the findings appeared to reflect a more tolerant attitude toward illicit drugs such as marijuana in recent years.

He suggested the problem may be compounded by the failure of the Clinton administration to focus on the issue, noting that the president has yet even to nominate a drug-policy director.