LOS ANGELES (AP) _ Some mental patients suffered severe relapses after researchers studying schizophrenia took them off their medication without getting proper consent, a federal agency said. One patient killed himself.

The Office of Protection from Risk Research, part of the National Institutes of Health, leveled the allegations against the University of California at Los Angeles in a report obtained by The New York Times and the Los Angeles Times.

The report is initial findings and could change after the school has given its formal response, NIH spokesman Don Ralbovsky said today. Among the things that haven't been decided yet is whether the school will face sanctions, he said.

A co-director of the study defended it, saying it is important to determine in early stages of schizophrenia if patients can maintain their equilibrium without medicine.

''Entry into the study was completely voluntary and patients were free to indicate that they wanted to withdraw,'' Keith Nuechterlein, a clinical psychologist, told The Associated Press today.

Nuechterlein said the researchers are rewriting the forms to include more details about the risks. But he said there was no attempt to conceal the risks.

The study still is going on, he said. None of the patients is in a phase of the study in which medication is withheld.

Sophia Glezos, spokeswoman for the National Institute of Mental Health, which funded the study, said the institute approved the study's procedures but did not check the wording of the consent form.

In the study, 23 of 50 patients under treatment for schizophrenia suffered severe relapses after their medication was interrupted, the newspapers said today. Neither Glezos nor Ralbovsky would provide The Associated Press with a copy of the report.

The relapses ranged from depression to paranoia and psychotic episodes, Nuechterlein said.

One patient threatened to kill his parents and tried to go to Washington to assassinate President Bush on orders from space aliens, the newspapers reported. Another jumped to his death off a building at the university.

The patients' parents complained to the NIH, prompting the review.

The report said the research project, which began in 1983, failed to meet standards set by the Department of Health and Human Services.

Nuechterlein said no patients were intentionally plunged into a severe schizophrenic relapse. Rather, he said, they experienced symptoms as a matter of course because they were off their medication.

Medication is withheld because many anti-psychotic drugs can cause severe and irreversible twitching and tremors, he said. He said patients never were denied the opportunity to resume medication.

Patients in the study received ''informed consent'' documents that stated their medical problems could ''improve, worsen or remain unchanged,'' the newspapers said.

Schizophrenia is characterized by delusions, hallucinations, depression and inability to think clearly. The UCLA team has been studying a drug called Prolixin.