Psychiatric researchers here are about to begin a series of carefully controlled experiments to determine if schizophrenics can be cured by cleansing their blood with an artificial kidney machine.

The $200,000, federally funded study follows an earlier, uncontrolled experiment in Florida which was said to show "remarkable improvement" in 14 of 16 schizophrenic patients who underwent similar treatment.

Dr. William T. Carpenter Jr., director of the Maryland Psychiatric Research Center, said today he doubts the treatment will work. But he said it's important to keep an open mind.

Carpenter's center is conducting the research in cooperation with the University of Maryland Hospital.

He said the study is desperately needed, whether or not he believes the treatment will be effective, because news of the Florida study has generated more inquiries at the National Institute of Mental Health about hemodialysis, the use of the artificial kidney, "than any other subject in the history of the institute."

Schizophrenia, a mental disorder characterized by disturbances of thinking, mood and behavior, is one of the most disabling, least understood forms of mental illness. There are records of it having been observed for at least 3,400 years, but there is no known cure.

It is estimated that between 500,000 and one million people in the United States need treatment for schizophrenia, but the only treatments available now are drugs, which are only partially effective and which may have severe side effects.

Dr. Robert Cade, a Florida kidney specialist and the developer of the drink Gatorade, began the first experiments with dialysis and schizophrenics when he observed that a schizophrenic he was treating for kidney disease improved after her blood was cleansed by being run through the kidney machine.

But Cade's later study of 16 patients was uncontrolled. That is, all the patients received dialysis; all knew they were receiving dialysis, and all expected that the treatments would work. Carpenter said any of those factors could have affected the study's apparent outcome.

The Maryland researchers hope to avoid the pitfalls of the Florida group. Each of the 20 or 22 schizophrenic patients in the study will undergo minor surgery on one arm to provide easy access for the needles that will draw the blood from their bodies into the dialysis machine and return it to their bodies after it is cleansed.

The group will then be divided in half, and each group will begin a 10-week program of twice-a-week, six-hour dialysis sessions.

One group, however, will be receiving what Carpenter and Kidney specialist Dr. John H. Sadler described as "sham dialysis." The patient's blood will be drawn through the tubing of the kidney machine, but it will not pass through a series of filters and cleansing fluid, as it will with the patients actually receiving dialysis.

The only person who will know which patients are receiving real dialysis and which are receiving the sham will be the technician who sets up the machines before each session, Carpenter said. At the end of the first 10 weeks, the two groups will be switched.

It has long been theorized that schizophrenia might be caused by some chemical imbalance or toxic substance in the blood, but no one has ever isolated such a substance.

If the dialysis experiment proves successful, said Carpenter, the next step would be to attempt to find the element the machine eliminates from the blood which causes the patient's schizophrenic behavior.

But if the Maryland experiment and a second federally funded test being conducted by Cade in Florida are successful, they will present the country with a potentially enormous financial and moral dilemma.

The government estimates it will soon be spending $3 billion a year for the care of 50,000 kidney patients receiving regular dialysis to keep them alive. Even assuming that schizophrenics would require only a fraction of the medical care, the cost of providing regular dialysis to a million scizophrenics could run as high as the combined cost of all federal health programs.The principal programs, Medicare and Medicaid, cost nearly $50 billion a year.

But, "if there is an effective treatment, it should be known so the decision can be made as to how much can be afforded and who would get it," Carpenter said.

The knowledge gained from dialysis experiments, he said, may pave the way for simpler treatments with less risk and less cost.

And if such experiments are not carried out, "it seems like you could have a multi-billion-dollar business in schizophrenia treatment before you even knew if it works."