Can taking a daily fish oil supplement prevent mental illness in high risk individuals?

A new study (1) has found that taking a daily fish oil supplement that is rich in long-chain omega 3 fatty acids may help to prevent against psychotic disorders.

The study(1) was carried out to see whether a daily long chain omega 3 fatty acid supplement could help reduce the rate of progression to psychotic disorders in adolescents and young adults, aged 13-25 years old, who were at high risk of developing a psychiatric condition.  Long chain omega 3 fatty acids, EPA and DHA, are naturally found in oily fish such as salmon, trout, mackerel and sardines.  There have been numerous studies linking these fatty acids to reduced incidence of depression and other mood related disorders. 


This study (1) was well designed and carried out between 2004 and 2007 and involved 81 individuals at, what the authors describe as, ultra-high risk of psychotic disorder.  The researchers included people who met at least one of the following three criteria: having low-level psychotic symptoms; having transient psychotic symptoms; or having a schizophrenia-like personality disorder or a close relative with schizophrenia, along with a sharp decline in mental function within the past year.  These are individuals which may have weak or transient psychotic symptoms, and already show schizophrenia-like brain changes.  Psychiatrists now know how to identify these at-risk individuals but at the moment they don’t really know how best to treat them in order to prevent disease progression. Prescribing antipsychotic medications is often the course of action and could be helpful, however, these medications have serious side effects, and can also be stigmatizing.  Many individuals also do not wish to take these kinds of medications and look for safer, more natural alternatives.  Also this kind of preventative anti-psychotic medication may not be necessary, since only about a third of people at high risk for psychotic disorders will go on to develop full-fledged mental illness in a given year.  For these reason the authors of the study (1) tested fish oils, a natural and safe option.  The authors of the study note that there is considerable evidence that abnormal fatty acid metabolism may contribute to the development of schizophrenia – that is why they designed the trial


Participants (1) received either 1.2g per day of long chain omega 3 fatty acids or a placebo (inactive dummy pill) for 12 weeks.  This was followed by 40 weeks of monitoring.  Blood tests were used to look at the level of fatty acids in the red blood cells before and after treatment.  At the end of the study 2 out of the 41 individuals (4.9%) in the omega-3 supplement group had transitioned to having a psychotic disorder compared to 11 out of the 40 (27.5%) in the placebo group.  Individuals taking fish oil also showed significant reductions in their psychotic symptoms and improvements in function.

The authors(1) conclude that long chain omega 3 fatty acids reduce the risk of progression to psychotic disorder in young people at risk of developing these disorders.  The researchers note that fish oil could also potentially be used to prevent or delay the onset of chronic depression, bipolar illness, and substance abuse disorder, all of which are far more common than psychotic illness.  They also say that these fatty acid supplements are safe and effective and are now planning a large, multicenter trial, of fish oil supplementation for the prevention of psychotic illness in 320 at-risk people.


It is not exactly known how the fatty acids are working to prevent psychotic illness, however readers of this blog will already be aware of the mounting evidence for the essential health benefits of omega 3 fatty acids.  These fatty acids are essential for the structure and proper functioning of the brain.  They are also key to the proper functioning of two specific brain chemical signalling systems: the dopamine and serotonin systems, which have been implicated in schizophrenia.  Fish oil also boosts levels of the antioxidant glutathione.  Glutathione protects the brain against oxidative stress.


In a BBC News article (2), Alison Cobb, of the mental health charity Mind, said: “If young people can be treated successfully with fish oils, this is hugely preferable to treating them with antipsychotics, which come with a range of problems from weight gain to sexual dysfunction, whereas omega-3s are actually beneficial to their general state of health.  These are promising results and more research is needed to show if omega-3s could be an alternative to antipsychotics in the long term.”

Since Omega 3 fatty acids are so vital for health, as I have previously recommended, it may be worth considering a daily fish oil supplement – especially if you do not regularly (at least twice weekly) consume oily fish.  For vegans and vegetarians a flaxseed oil supplement may be considered.  Unfortunately the shorter chain omega 3 fats (alpha linolenic) provided by flaxseeds are not easily converted by the body into the longer chain forms found in fish oils, but having a dietary source of omega 3 is essential to health.  There are now some EPA/DHA supplements available for vegetarians/vegans that are made from algae.

(1)Amminger GP et al.  Long-chain omega-3 fatty acids for indicated prevention of psychotic disorders: a randomised, placebo-controlled trial.  Arch Gen Psychiatry.  67:146-154
(2)BBC News.  Fish Oil Supplements ‘beat psychotic illness’.  Tuesday 02 February 2010.
Written by Ani Kowal