A reader writes, "I'm sure this story will sound familiar. It has happened many times. It is about a high school student who got hooked on drugs that were, at first, supplied free to him.

"By the time he was a senior, his need for bigger and bigger doses had gotten him into very substantial debt and the supplier had begun to threaten the young man and his family with bodily harm. To try to extricate himself and keep his family from being harmed, the young man robbed a bank. He was caught, tried, found guilty, and is now awaiting sentence.

"It is easy to ask, 'Where were the boy's parents while all this was going on?' But unless you have yourself raised teen-agers in this era in which narcotics are everywhere and young people feel they must show their 'independence,' you should not be quick to judge.

"The schools have developed all sorts of student organizations: stamp clubs and chess clubs and camera clubs, for example. Perhaps they should encourage the formation of clubs devoted to studying and preventing drug abuse.

"The students themselves are in the best position to know who is using drugs, who is selling them, and when and where the transactions take place.

"They could be a big help to school authorities and to police if a way could be found for them to funnel information to the proper place. Adults, too, should have a number they can call if they see a crime being committed, especially a drug-related crime. Most people with crime information might hesitate to identify themselves for fear of reprisal, but I think the police would be glad to have such information anonymously."

You are right, my friend. Most police departments will check out information even when it is supplied by anonymous tipsters.

D.C. police have long maintained a special confidential phone line that is answered 24 hours a day. Anybody who has information about a crime can call in and tell the police what he has seen or heard that involves any crime, not just a drug-related crime.

The number of the confidential line is 393-2222. I included it in today's headline so that you can clip it and post it near your phone for future reference.

Lt. Daniel J. Kerr of the Community Relations Division of the D.C. police tells me that he will be happy to assign a specially trained officer to address any community group that wants guidance in handling a problem, whether it be a citizens' association concerned about pedestrian safety at a dangerous intersection or a school principal who needs help with the narcotics problem in his school. "If a teacher or a principal wants our cooperation," Kerr told me, "all they have to do is ask. They can write to the Community Relations Division of the Metropolitan Police Department, 300 Indiana Ave. NW. Or they can phone 727-4283."

It should be noted that just a few days ago Mayor Barry launched an appeal for all city employees equipped with two-way radios to report any crimes they see. Arrangements have been made for each department's radio dispatcher to transmit such crime tips to the police at once.

It is true, as school authorities have said, that the narcotics problem is too big for them to handle alone. But now there is no need for them to feel alone. Help is available to those who ask for it and are willing to cooperate with the police.

Excellent self-help may also be available. Many students do not use drugs. They would like to help their friends avoid becoming trapped in a drug habit. If school authorities would organize the constructive peer pressure that's available to them, there might be less need for the police to apprehend drug law violators after they are already in trouble up to their chins. It's worth trying.