They may have golden promise, but more trials are needed sidsnapper/Getty

There may finally be a way to stop people progressing beyond the first signs of schizophrenia – fish oil. When people with early-stage symptoms took omega-3 supplements for three months, they had much lower rates of progression than those who did not, according to one small-scale trial.

People with schizophrenia are usually diagnosed in their teens or 20s, but may experience symptoms for years beforehand, such as minor delusions or paranoid thoughts. Only about a third of people with such symptoms do go on to develop psychosis, however, and antipsychotic drugs can cause nasty side effects, so these are rarely given as a preventative.

Fish oil supplements, which contain polyunsaturated fatty acids like omega-3, may be a benign alternative. These fatty acids may normally help dampen inflammation in the brain and protect neurons from damage, and lower levels in the brain have been implicated in several mental illnesses.


Tests have found that people with schizophrenia have lower levels of these fatty acids in their blood cells, suggesting the same could be true for their brain cells. Fish oil supplements have been investigated as a treatment for adults with schizophrenia, but so far results have been mixed – four trials found no benefit while another four found a small reduction in symptoms.

But a study that gave omega-3 fish oil pills to younger people suggests that what matters is catching the condition in time. The trial followed 81 people aged 13 to 25 with early signs of schizophrenia. Roughly half took fish oil pills and half took placebo tablets for three months. A year later, those given fish oils were less likely to have developed psychosis.

New trajectory

That was seven years ago. The researchers have now followed up 71 of the participants and found that just 10 per cent of those given fish oils went on to develop schizophrenia, compared with 40 per cent of the placebo group. “We may have put them on a different trajectory,” says team member Paul Amminger of the University of Melbourne, Australia.

The results are striking, says David Taylor of the Maudsley Hospital in London. But he cautions that this was a small trial and the results need to be reproduced.

Nigel Barnes of Birmingham and Solihull Mental Health NHS Foundation Trust in the UK agrees that the study needs repeating with a larger group, but says that it’s reasonable for people to give fish oils a try. However, he warns that over-the-counter products may not have the right dose of the right fatty acids to be of use.

Amminger says the best approach for those at risk of developing schizophrenia would probably be to combine fish oil supplements with talking therapies.

Journal reference: Nature Communications, DOI: 10.1038/ncomms8934