New research has shown that adolescents with higher levels of omega-3s in their blood are less likely to develop a psychotic disorder in early adulthood, suggesting that this may have a preventative effect on reducing the risk of psychosis.

The study, led by researchers from the RCSI University of Medicine and Health Sciences, is published in Translational Psychiatry.

Over 3,800 people in the Bristol Children of the 1990s Health Study were screened for psychotic disorders, depressive disorders, and generalized anxiety disorders, ages 17 and 24.

During these tests, blood samples were taken and the researchers measured the levels of omega-6 fatty acids, which generally increase inflammation in the body, and omega-3 fatty acids, which generally decrease inflammation.

While there was little evidence that fatty acids were associated with mental disorders by the age of 17, researchers found that 24-year-olds with psychotic disorders, depressive disorders, and generalized anxiety disorders had higher levels of omega-6 than those compared to these Omega-3 fatty acids exhibited without these disorders.

The researchers also found that 24-year-olds with psychotic disorder had lower levels of DHA, an omega-3 fatty acid typically found in oily fish or supplements, than 24-year-olds without psychotic disorder. In a group of over 2,700 people tracked over time, teenagers with higher DHA levels were 56% less likely to develop a psychotic disorder by the age of 17 seven years later by the age of 24 . This suggests that DHA in adolescence may have a potential preventative effect in reducing the risk of psychosis in early adulthood.

These results remained consistent when other factors such as gender, body mass index, tobacco smoking, and socioeconomic status were taken into account.

“The study needs to be repeated, but if the results are consistent, these results suggest that improved dietary intake of omega-3 fatty acids in adolescents, for example from oily fish like mackerel, might prevent some people from developing early psychosis develop twenties, “said Professor David Cotter, lead study author and professor of molecular psychiatry at RCSI.

“The results may also raise questions about the relationship between the development of mental disorders and omega-6 fatty acids, which are typically found in vegetable oils.”

David Mongan, RCSI PhD student and ICAT (Irish Clinical Academic Training) fellow, analyzed the data under the supervision of Professor David Cotter and Professor Mary Cannon of the RCSI Department of Psychiatry. The ICAT program is supported by the Wellcome Trust and the Health Research Board, the National Doctors Training and Planning of the Health Service Executive, and the Department of Health and Social Services, Research and Development in Northern Ireland.

We need to do more research to understand the mechanisms behind this effect, but it could potentially be related to reducing inflammation or reducing inadequate clipping of brain connections during puberty. “

Dr. David Mongan, first author of the study, trainee psychiatry and PhD student at RCSI

This research was supported in part by a Science Foundation Ireland (SFI) research grant and co-funded under the European Regional Development Fund. The UK Medical Research Council, Wellcome Trust and the University of Bristol provided key support for Children of the 1990s, also known as the Avon Longitudinal Study of Parents and Children (ALSPAC). The data collection used in this study was jointly funded by the Medical Research Council and the Wellcome Trust.


Journal reference:

Mongan, D. et al. (2021) Plasma Polyunsaturated Fatty Acids and Mental Disorders in Adolescence and Early Adulthood: Cross-Sectional and Longitudinal Associations in a General Population Cohort. Translational Psychiatry.


Please enter your comment!
Please enter your name here