A leading authority on drug abuse, both in its clinical and societal aspects, Dr. Robert DuPont not only grasps the extent of this growing problem but urges a dynamic approach by family members in preventing and treating drug abuse.

"Gateway drugs" -- alcohol, marijuana and cocaine -- are the ones that lead young people into drug dependence, says DuPont; they're the gateway to all other drugs. And they are the most widely used of the mind-altering drugs.

A professor, practicing psychaiatrist and internationally known figure in the battle against drugs, DuPont tries hard to arouse his fellow citizens to take an active part in reversing it. The gateway drugs, he says, are widely believed to be harmless, nonaddictive and easy to control or quit -- but they're not.

And the belief that they're harmless, he says, makes them all the more likely to produce full-blown dependence. While many people can get by with casual use of drugs for years with few resulting problems, there's no telling when the "addiction switch" will turn on, DuPont says. "We are all vulnerable to drug dependence, and that vulnerability is more likely to be revealed if we use any drug regularly and heavily for a prolonged period of time."

The three drugs he designated as "gateway" are the most widely used of the mind-altering, or psychoactive, drugs: 100 million Americans currenly use alcohol, 57 million have used marijuana at least once, and 22 million have tried cocaine. The proportions of those who become dependent are less clear, but DuPont says that particularly among adolescents, the rates of drug usage are 20 to 30 times what they were two decades ago.

DuPont starts by mapping the drug problem: the unprecedented rise in drug use by massive numbers of people, the explosive growth of the cocaine market. (The U.S. cocaine marked, he says, is estimated at more than $25 billion a year.) Because nobody in America is insulated from effects of the drug problem, this book provides all of us an opportunity to take its measure and to face the tough question: What are we going to do about it?

DuPont urges family members to take firm charge and get the user to a treatment program. "Parents need hardly apologize for this purposeful and temporary tyrany," he says.

The book is directed toward family members, all ages. Drug users, DuPont believes, are not likely to read it or to apply it to themselves and their problems, denial being such a powerful trait in drug behavior. But a concerned family member not personally into drugs can be guided to take constructive action with some confidence of doing the right thing and with deepened understanding of the drug victim.

Discussion is not limited to the three gateway drugs, and not entirely directed to family members. The community is involved, too, says DuPont; this means the schools, the police, military service, prisons, professional sports. Prescription drug dependence is examined. DuPont describes the various drug abuse treatment programs, tells how to go about making treatment succeed, gives some key principles to apply.

Ann Landers has written a vigorous preface for the book. DuPont has for some years been on her roster of experts consulted for authoritative advice.