Omega-3 index as risk factor in psychiatric diseases: a narrative review

Helena Sofia Antão, Ema Sacadura-Leite, Narcisa Maria Bandarra, Maria Luisa Figueira

Research output: Contribution to journalReview articlepeer-review

10 Downloads (Pure)


Numerous studies have described associations between the omega-3 index (defined as the RBC percentage of EPA and DHA) and mental conditions, but no risk stratification or target value has gathered consensus so far. This narrative review aims to summarize the published data on the association between omega-3 index and mental illness and to contribute to the concept of an omega-3 index in the field of mental health. The bibliographic searches have been carried out in PubMed, Scopus and Web of Science databases to find relevant English language original research studies related to that association. The study search and selection process were registered in a PRISMA flow. Thirty-six studies were included in this review examining the links between omega-3 index and postpartum depression (3), major depression (15), major depression and bipolar disorder (1), bipolar disorder (4), schizophrenia and major depression (1), schizophrenia and other psychosis (5) and dementia (7). Thirty of these studies found either significant differences in omega-3 index between patients and controls or inverse relationships between omega-3 index and disease severity. The published evidence is compelling enough to suggest omega-3 index as a risk factor for some psychiatric diseases, specifically, major depression, postpartum depression, psychosis, and dementia. In occidental populations, we propose a risk threshold of (a) 4–5% in major depression and dementia, (b) 5% in postpartum depression, and (c) 4% for psychosis transition.

Original languageEnglish
Article number1200403
JournalFrontiers in Psychiatry
Publication statusPublished - 2023


  • biomarker
  • bipolar disorder
  • dementia
  • depression
  • Omega-3 index
  • psychosis
  • risk factor
  • schizophrenia


Dive into the research topics of 'Omega-3 index as risk factor in psychiatric diseases: a narrative review'. Together they form a unique fingerprint.

Cite this