America has virtually abandoned the seriously mentally ill who cannot afford treatment, according to a report released last week by two Washington area advocacy groups.

More than 250,000 people suffering from schizophrenia and manic-depressive illness, both of which are serious thought and mood disorders, live in public shelters, on the streets and in prisons and jails, said the report by Public Citizen and the National Alliance for the Mentally Ill.

Many others among the nation's 2 million seriously mentally ill cannot afford medical treatment or adequate housing and live in communities where no vocational rehabilitation services are available, the groups say.

"The majority of all of these are receiving little or no psychiatric treatment because most public psychiatric services have broken down completely," the report said.

The report, "Care of the Seriously Mentally Ill: A Rating of State Programs," evaluates the services provided by each state and scores them accordingly. The biennial review began in 1986. The report assesses hospital services, outpatient and community support services, vocational rehabilitation, housing services and programs for seriously emotionally disturbed children.

Vermont ranked highest, scoring 17 of a possible 25 points. Hawaii finished last, as it did in the 1986 and 1988 editions of the report, with 2 points.

Sidney Wolfe, who heads the health research group Public Citizen, founded by consumer advocate Ralph Nader, said some communities have built "great model programs." Therefore, he said, "it becomes more and more intolerable when {others} don't adopt them."

Among the problems with the public system are that "too many mental health professionals have abandoned the public sector and {seriously} mentally ill people," said Laurie Flynn, executive director of the National Alliance for the Mentally Ill, a nonprofit Arlington-based group whose members are relatives of the chronically mentally ill.

Since the federal government began subsidizing training of mental health professionals in 1945, the number of psychiatrists has grown from 3,000 to 40,000. The number of psychologists has risen from 4,200 to 70,000 and psychiatric social workers, from 2,000 to about 80,000.

However, the report says, this publicly subsidized training has been "an abysmal failure."

"The reason quite simply is that once psychiatrists, psychologists and psychiatric social workers were trained, almost all of them abandoned the public sector for the monetary rewards of private practice," the report said.

Surveys consistently indicate that psychologists and psychiatrists in private practice see very few people with serious mental illnesses. A 1980 survey found that only 6 percent of patients who had consulted psychiatrists and 3 percent of patients seen by psychologists had ever been hospitalized for mental illness.

The gap is being filled by foreign medical students, who now constitute about two thirds of the physicians in public psychiatric hospitals and clinics, the report said. Another problem, the report said, is that too many mental health programs spend too much time and money counseling people who are not seriously mentally ill.

The report recommends requiring public mental health programs to spend at least 75 percent of resources on the seriously mentally ill. It also suggests psychologists, psychiatrists and psychiatric social workers be required to donate one hour a week to public programs.