Marijuana use has declined among young people for three years in a row, and may continue to decline for the next 15 years, according to the nation's chief drug abuse officer.

At the same time, he suggested that smoking marijuana may lead to using cocaine and heroin and that researchers should revive that old, discarded theory.

Quoting the preliminary results of a new nationwide survey of drug use among high school seniors, William Pollin, head of the National Institute of Drug Abuse, said yesterday, "The preliminary figures for 1981 show the same trend downward for three years now, and that is coming after two and a half decades of very, very dramatic increases."

He said that, although trends in statistics sometimes appear and disappear unexplainably, this time the numbers in several different surveys coincide. They also find strong support in surveys which show dramatic changes of attitude among high school students about using marijuana.

The decline in marijuana use by white teenagers will probably continue throughout the next 15 years, Pollin testified at a hearing of a Senate Labor and Human Resources subcommittee. He also noted that, while American marijuana use has declined, it is still higher than in any other developed country.

In a telephone interview later, he explained that this decline in drug use may be only one of many manifestations of an important fact about the country--that the number of teenagers is dropping relative to the rest of the population. He said statisticians have begun predicting that this decline will result in a drop in social problems among teenagers--including a halt in the declining scores on educational tests, a relative lowering in crime statistics among teenagers, and other social measurements.

The new survey also shows an attitudinal change toward marijuana, with negative attitudes toward marijuana use increasing from 35 per cent to more than 50 per cent. A majority of high school seniors now believe in the negative health effects of marijuana--that it causes a decrease in energy and an increase in personality problems.

Despite the decline in drug use, Pollin cited another new nationwide survey on marijuana use which suggests that marijuana use leads to cocaine and heroin use by a significant number of people. The study also indicates a link between heavy marijuana use and crime, though it does not indicate if crime results in drug use or vice versa, or whether there is no causal connection.

Pollin testified that the "stepping stone" hypothesis--that a person using marijuana is more likely to move on to harder drugs such as cocaine and heroin--"was rejected prematurely and now needs serious re-evaluation."

He said one recent nationwide study showed that, among those who had never used marijuana, fewer than one percent went on to use cocaine and heroin. But of those who had used marijuana 1,000 times or more, 73 percent went on to cocaine and 33 percent went on to heroin.

Pollin said marijuana smokers use other drugs to a "significantly greater" degree than other people.