Fish Oil May Reduced Risk Of Psychotic Disorders In High Risk Individuals

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Main Category: Schizophrenia
Also Included In: Mental Health;  Psychology / Psychiatry;  Pediatrics / Children's Health
Article Date: 03 Feb 2010 - 7:00 PDT

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A new study suggests that people at very high risk of developing psychotic disorders appear less likely to to do so after taking fish oil for three months.

The study was conducted by Dr G Paul Amminger from the Medical University of Vienna in Austria, and the Orygen Youth Health Research Centre in Melbourne, Australia, and colleagues, and is reported in the February issue of the JAMA/Archives journal Archives of General Psychiatry.

As Amminger and colleagues mentioned in their background information, although there is a lot of controversy surrounding the use of current antipsychotic medication to try and prevent psychotic disorders, there is evidence that early treatment in schizophrenia and other psychoses has been linked to better outcomes.

There was also some evidence that long-chain omega-3 polyunsaturated fatty acids (PUFAs) could be be beneficial for schizophrenia and a range of other psychotic conditions, and noted that individuals with schizophrenia may have an underlying dysfunction in fatty acid metabolism.

So, given that omega-3 PUFAs are generally considered good for health and have no clinically relevant adverse side effects, they thought it would be worth investigating whether they might help prevent psychosis.

Their results showed that that individuals at very high risk of developing psychosis seemed less likely to develop psychotic disorders after taking a 12-week course of fish oil capsules that contained long-chain omega-3 PUFAs.

The setting for the randomized, double-blind, placebo-controlled trial, which took place from 2004 to 2007, was the psychosis detection centre of a large public hospital in Vienna.

The researchers wrote that they set out to determine whether omega-3 PUFAs "reduce the rate of progression to first-episode psychotic disorder in adolescents and young adults aged 13 to 25 years with subthreshold psychosis".

81 individuals considered to be at ultra-high risk of psychotic disorder took part in the study. They either had mild psychotic symptoms, transient psychosis or a there was a family history of psychotic disorders and a decrease in functioning. These criteria suggest that the risk of a person becoming psychotic could be as high as 40 per cent in the ensuing 12 months.

The participants were double-blind randomized to take either daily capsules of fish oil or placebo (double blind means neither the participants nor the drug administrators knew whether the capsules they were given contained the active ingredient or a placebo).

The daily dose was 1.2 g of omega-3 PUFA or placebo, and they took the capsules for 12 weeks, then underwent monitoring for a further 40 weeks (total study period was 12 months).

The main outcome that the researchers measured was transition to psychotic disorder. They also measured, as secondary outcomes, symptomatic and functions changes, and the ratio of omega-6 to omega-3 PUFAs in "erythrocytes was used to index pretreatment vs posttreatment fatty acid composition", they wrote.

76 of the 81 participants completed the 12 months of the trial, and after analysing the results, the researchers found that:

• 2 of the 41 subjects in the omega-3 PUFA fish oil group (4.9 per cent) and 11 of the 40 (27.5 per cent) in the placebo group transitioned to psychotic disorder (P=.007).


• The difference between the fish oil and the placebo groups in the cumulative risk of progression to full psychosis was 22.6 per cent (95 per cent confidence interval CI ranged from 4.8 to 40.4 per cent).


• Compared with placebo, omega-3 PUFAs also significantly reduced positive symptoms (P=.01), negative symptoms (P = .02), and general symptoms (P = .01), It also and improved functioning (P = .002) compared with placebo.


• There was no difference in side effects between the two groups.

Based on these results, Amminger and colleagues estimated that 4 adults would need to be treated with omega-3 PUFAs to prevent one from developing psychosis over a 12 month period.

Speculating on how consuming fish oil with omega-3 PUFAs may lead to such changes, the authors said it could be that they affect cell membranes and neurotransmitter chemistry in the brain. They noted that:

"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."

Young people are often put off taking current antipsychotics because of the "stigmatization and adverse effects -- which include metabolic changes, sexual dysfunction and weight gain," they wrote.

In contrast, omega-3 PUFAs may lead to some digestive complaints, but they are largely free of "clinically relevant adverse effects," they noted, adding that they have "excellent tolerability, public acceptance, relatively low costs and benefits for general health".

The researchers concluded that:

"Long-chain omega-3 PUFAs 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: A Randomized, Placebo-Controlled Trial."
G. Paul Amminger; Miriam R. Schäfer; Konstantinos Papageorgiou; Claudia M. Klier; Sue M. Cotton; Susan M. Harrigan; Andrew Mackinnon; Patrick D. McGorry; Gregor E. Berger.
Arch Gen Psychiatry, Feb 2010; 67: 146 - 154.

Source: JAMA and Archives Journals.

Written by: Catharine Paddock, PhD
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