CHICAGO — Fish oil pills might be able to save some young people with signs of mental illness from descending into schizophrenia, according to a preliminary but first-of-its-kind study.

The Austrian study of just 81 patients comes from leaders in the field of youth mental health and adds to evidence suggesting severe mental illness might be prevented with the right intervention.

Though it sounds incredibly simple, fish oil fits one hypothesis for what causes schizophrenia, a possible difference in how the body handles fatty acids.

"If it works, it will be an absolutely tremendous development," said Dr. Jeffrey Lieberman, chairman of psychiatry at Columbia University Medical Center in New York, who wasn't involved in the new study. More research is needed to see if the results are accurate, he said.

The researchers are beginning a larger international study in eight cities with hopes of replicating their findings.

Schizophrenia is a severe mental illness that strikes adolescents and young adults. About 2.4 million Americans have the disorder, which is treated with antipsychotic medication.

Since the 1990s, researchers have wondered if the disease could be stopped in its earliest stages, before it fully overpowers a person's grip on reality. Studies have tried antipsychotics in select young people, but troubling side effects pose ethical questions and results have been mixed.

For the new study, researchers identified 81 people, ages 13 to 25, with warning signs of psychosis. The signs include sleeping dramatically more or less than usual, growing suspicious of others, believing someone is putting thoughts in their head or thinking they have magical powers. The young people in the study sought professional help and most were referred by psychiatrists at the Medical University of Vienna, Austria.

Researchers randomly assigned 41 of the patients to take four fish oil pills a day for three months. The daily dose of 1,200 milligrams was about what many people take to get the protective benefits of fish oil for the heart and costs less than 40 cents a day. The rest of the patients received dummy pills. After one year of monitoring, 2 of 41 patients in the fish oil group, or about 5 percent, had become psychotic, or completely out of touch with reality. In the placebo group, 11 of 40 became psychotic, about 28 percent.

No one knows what causes schizophrenia, but one hypothesis says people with the disease don't process fatty acids correctly, leading to damaged brain cells.

Omega-3 fatty acids in fish oil could help brain cells to repair and stabilize, the researchers speculate. Some prior studies on omega-3 supplements in people with full-blown schizophrenia have shown benefits.