For years now we and others have been expressing alarm over the increasing abuse of the dangerous drug Phencyclidine, commonly known as PCP. Its use can result in wildly violent behavior. Users can believe they have superhuman strength. They are also oblivious to pain. Chronic use can result in permanent brain damage.

The problem has gotten worse. PCP's use is called "very pervasive," by Jay Carver, director of the city's pretrial services agency. Statistics from city agencies show that, since 1981, emergency room admissions in city hospitals for PCP intoxication have risen 300 percent. PCP-related arrests have risen 600 percent in the same period. City officials say that one-third of the emergency admissions to St. Elizabeths in 1984 involved people suffering from PCP-induced psychosis. A study examining suicides by blacks in the District over a four- year period showed that half of the cases were drug-related, and in 72 percent of those drug-related cases, the drug was PCP. Among juveniles, the drug continues to be a very serious problem. Drug tests for youths coming into the juvenile justice system show that those involved with drugs are "almost exclusively" PCP users.

Why? Despite its potency, it is so cheap for the young and the poor to buy that, in some instances, it is even less expensive than marijuana. It is simple to manufacture. And to youthful buyers, it is very misleading, known on the streets by such seemingly harmless names as "Lovely," "Angel Dust" and "Love Boat." According to one Drug Enforcement Administration official, "They think this stuff is benign because they aren't sticking a needle into their arms."

City officials have had facilities geared toward heroin addicts for years. But PCP users show up in a bewildering array of places: in regular hospitals, at St. Elizabeths, at heroin abuse treatment facilities. Those officials say they will have two new 25- bed residential treatment facilities ready in the next few months for treating users of PCP and other drugs. Plans also call for a 10-to 30-bed PCP detoxification facility for juveniles.

There has been more than enough time to gauge the use and effects of PCP. The city could have been much farther down the road of combating the problem than it is. Others have more of a job to do as well. If juveniles still view this drug as largely harmless, as is reported, then schools, churches and neighborhoods have a larger role to play. PCP won't leave the streets; the only way to prevent its spread, according to one estimate, is to warn users and would-be users that PCP "fries your brain" -- permanently.