Fish oil may reduce the risk of psychotic disorders in high-risk individuals

Individuals at extremely high risk of developing psychosis appear less likely to develop psychotic disorders following a 12-week course of fish oil capsules containing long-chain omega-3 polyunsaturated fatty acids, according to a report in the February issue of Archives of General Psychiatry.

Researchers at the Medical University of Vienna in Austria conducted a randomised, double-blind, placebo-controlled clinical trial to asses the effect of long-chain omega-3 polyunsaturated fatty acids on the risk developing full-blown psychosis in 81 individuals considered at ultra—high risk. These individuals either had mild psychotic symptoms, transient psychosis or a family history of psychotic disorders plus a decrease in functioning.

For 12 weeks, 41 individuals were assigned to take daily fish oil capsules containing 1.2g of Omega-3 polyunsaturated fatty acids, while 40 were assigned to take aplacebo. A total of 76 (93.8 per cent) completed the intervention. By the end of the study, two (4.9 per cent) in the Omega-3 group and 11 (27.5 per cent) in the placebo group had transitioned to psychotic disorder. The difference between progression to psychosis was 22.6 per cent.

The researchers concluded that the fatty acids were are a promising intervention in individuals with schizophrenia, who may have an underlying dysfunction in fatty acid metabolism. "Early treatment in schizophrenia and other psychoses has been linked to better outcomes," the authors of the paper wrote.

"Given that sub-clinical psychotic symptoms may predict psychotic disorder and psychosis proneness in a population may be related to the rate of psychotic disorder, intervention in at-risk individuals holds the promise of even better outcomes, with the potential to prevent full-blown psychotic disorders."

Based on the results, the authors said they estimated that four adults would need to be treated with omega-3 fatty acids to prevent one from developing psychosis over a 12-month period. Polyunsaturated fatty acids also significantly reduced symptoms and improved functioning compared with the placebo. Rates of adverse effects were minimal and similar between the two groups.

The potential effects of fatty acids on psychosis development could result from changes to cell membranes and interactions with neurotransmitter systems in the brain, the authors noted. "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 antipsychotics for the prodromal \[early symptomatic\] phase," they wrote. "Stigmatisation and adverse effects — which include metabolic changes, sexual dysfunction and weight gain — associated with the use of antipsychotics are often not acceptable for young people."

In contrast, they said, omega-3 fatty acids were linked with some digestive complications but largely were "free of clinically relevant adverse effects", adding: "They have the advantage of excellent tolerability, public acceptance, relatively low costs and benefits for general health."

They concluded: "Long-chain omega-3 fatty polyunsaturated fatty acids reduce the risk of progression to psychotic disorder and may offer a safe and efficacious strategy for indicated prevention in young people with subthreshold psychotic states."

'Long-Chain Omega-3 Fatty Acids for Indicated Prevention of Psychotic Disorders', by G Paul Amminger et al. Arch Gen Psychiatry. 2010;67\[2\]:146-154.

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