Researchers from Switzerland, Austria and Australia have found that fish oil supplements can reduce the risk of developing schizophrenia and other psychotic disorders.

The new study included 81 high-risk patients with either mild psychotic symptoms, transient psychosis or a family history of psychotic disorders, plus a decrease in daily functioning. These criteria identify people whose risk of becoming psychotic may be as high as 40 percent in a one-year period.

For 12 weeks, 41 participants were assigned to take daily fish oil capsules containing 1.2 grams of omega-3 polyunsaturated fatty acids and 40 were given a placebo. Of the 76 patients who completed the study, two (4.9 percent) in the fish oil group and 11 (27.5 percent) in the placebo group progressed to psychosis, a difference of 22.6 percent.

The researchers believe it is the omega-3 in fish oil - that has beneficial effects in the brain. 

Dr G Paul Amminger of the Medical University of Vienna and his study colleagues said: "The finding that treatment with a natural substance may prevent, or at least delay, the onset of psychotic disorder gives hope that there may be alternatives to antipsychotic drugs."