A D.C. Superior Court judge has found that a residential treatment center in Texas that charges the District $120,000 a year for each District youth treated there is "grossly incompetent, abusive and literally life-threatening."

Judge Curtis von Kann made his findings about the Brown School in Austin after hearing testimony that a 17-year-old District youth placed there was injected with an antipsychotic drug when he refused to put on his pajamas and then received daily dosages of other powerful drugs despite no evidence of psychosis.

In a 78-page ruling, the judge said it was clear to him that authorities at Brown School were not using the drugs to treat the 17-year-old "but rather to control him and to make him compliant."

The judge ordered District officials to find a different program for the youth and strongly suggested that the city review the placement of other District youths who may be there.

It was unclear yesterday how many District youths are at Brown, a psychiatric and educational treatment center, but the judge said the 17-year-old indicated he knew of at least one other District resident at the facility, which was recently renamed the Health Care Rehabilitation center.

Nearly 300 District youths are placed in residential treatment programs outside the city for special therapeutic and educational programs that District officials say are unavailable in the city. About half of them are placed there by court order.

"The court has no reason to believe that the serious mistreatment displayed by Brown is limited to this one patient," the judge wrote in an opinion issued last week.

The residential placement program, administered by the Department of Human Services, has previously been criticized by youth advocates who complain that District officials rarely visit or monitor out-of-state programs. Such a lack of attention, juvenile defense lawyers said yesterday, inevitably leads to cases such as the one before von Kann.

"Most attorneys you talk to who have a child in a residential placement will tell you a horror story about what goes on there," said Diane Shust, head of the juvenile division for the Public Defender Service. "The District spends millions of dollars on this program but nobody really does any monitoring."

D.C. officials responsible for the program were unavailable for comment but a "memorandum of understanding" signed by Mayor Marion Barry and other city officials in December 1985 announced the formation of a monitoring committee to supervise the residential placements.

Brown officials could not be reached for comment yesterday, but defended their treatment of the 17-year-old during a court hearing on his placement.

The youth arrived at the Brown School last October after he pleaded guilty to simple assault in a juvenile case and the Residential Review Committee concluded he needed long-term treatment for emotional and behavioral problems.

The judge said that shortly after the teen-ager arrived at the school he began complaining about his placement in a cottage with children who had serious head and other injuries and said he wanted to go home. When he made threatening comments to other residents on the fourth day, he was escorted to his room and told to put on his pajamas.

When he refused and then resisted staff members' efforts to undress him, the judge said, seven staff members physically restrained the youth in a straitjacket and injected him with Haldol, a drug with painful side effects used most often with psychotic patients or in an emergency to calm violent behavior.

"They just blasted him," one doctor told the judge during the hearing.

Three weeks later the youth was transferred to another unit and a psychiatriast who had no previous contact with him prescribed large daily dosages of Mellaril and lithium, drugs similar to Haldol in use and side effects.

The judge also sharply criticized an additional prescription by the psychiatrist for Mellaril every hour "as needed."

Had the 17-year-old "actually been given 100 milligrams of Mellaril every hour it would have killed him," the judge wrote.

The judge said the youth was allowed to stop taking the Mellaril 15 days later when he developed "the shakes." The youth, who is currently in a group home in the District, left Brown around Christmas after a request for a hearing from his lawyer, Joseph Tulman.