For young people at high risk of developing schizophrenia, a 12-week intervention with omega-3 supplements might reduce the long-term risk of progression to the psychotic disorder, according to a paper published Tuesday in the journal Nature Communications.

Researchers from Australia and Austria carried out research over nearly seven years on the effect of omega-3 on the risk of psychotic disorder.

Schizophrenia typically manifests in adolescence or early adulthood and the majority of those affected gradually develop a variety of clinically significant signs and symptoms. Diagnostic criteria, termed "ultra-high risk" criteria have been developed to identify young people more likely to develop psychosis.

Previous studies have implicated a lack of omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) in the development of a number of mental health conditions and several trials have shown that supplementation with omega-3 PUFAs can reduce psychotic symptoms.

In 2010, researchers reported that dietary supplements of omega-3 PUFAs, in participants aged 13 to 25, prevented a first episode of a psychotic disorder for up to one year.

The new report showed that this intervention had long-term effects even after a period of 6.7 years for 71 of the original 81 participants. They found that 9.8 percent of the omega-3 group (4 out 41) developed psychosis compared to 40 percent (16 out of 40) in the placebo group. In addition, the placebo group showed more rapid onset of psychosis and a higher overall incidence of other psychiatric disorders.

But due to the limited size of the sample group, further research was necessary to discover a mechanism by which PUFA supplementation might improve mental health, the researchers also said.