Published in the journal Prostaglandins, Leukotrienes and Essential Fatty Acids, the study gathered researchers from Queen Mary University of London, Combined Universities Brain Imaging Centre and University of Roehampton in London.
“This study was the first to investigate the relationships between omega-3 PUFA status, measures of depression and anxiety, and functional connectivity between different brain regions in young adults with elevated but non-clinical depression,” study author Dr. Simon Dyall of the University of Roehampton told Nutraingredients.
He explained that subthreshold depression is an indicator of progression to major depressive disorder but is largely unexplored, especially in young adults.
“We found patterns of functional connectivity in brain regions shown to play a role in the neurobiology of depression were significantly associated with omega-3 PUFA status,” he added.
“What was really interesting was that these connectivity profiles (and indeed higher DHA and the Omega-3 Index) were associated with lower depression and anxiety.
“Overall, our results reveal previously unknown potential mechanisms linking lower omega-3 PUFAs and increased risk of depression in young adults, and also highlight the importance of exploring intervention studies in this area.”
Study details
The researchers conducted resting-state functional magnetic resonance imaging on 15 participants (three males and 12 females) between the ages of 18 and 29 who scored four or more on the Patient Health Questionnaire-8 (PHQ-8) and five or more on the Generalized Anxiety Disorder Assessment-7 (GAD-7).
Whole-brain, seed-based connectivity analyses were performed, and omega-3 and omega-6 status was assessed using dried bloodspot analysis.
PHQ-8 scores indicating subthreshold depression were negatively associated with DHA levels and Omega-3 Index.
“Both DHA and the Omega-3 Index were associated with i) weaker connectivity of the OFC (orbitofrontal cortex) and the angular gyrus and ii) greater connectivity of the amygdala with the PCC (posterior cingulate cortex), while both of these connectivity profiles (and indeed DHA and the Omega-3 Index) were associated with a lower depression and anxiety,” the researchers reported.
Future directions
Commenting on the study findings, Kaitlin Roke, PhD, director of scientific communication and outreach at the Global Organization for EPA and DHA Omega-3s (GOED), told Nutraingredients: “This research showcases a unique path forward in brain research, where brain imaging is utilized along with other health parameters.”
However, she said that the cost of this type of testing limits the sample size and that future studies should explore sex-specific differences.
The study also did not observe any association between EPA and depression/anxiety ratings or functional brain connectivity.
“Due to the small sample size, we cannot state with confidence that there was no relationship, and further work should seek to explore this relationship in subthreshold depression,” the authors wrote.
Roke noted that previous research supports the relationship between EPA and depression and that future studies should evaluate this association.
“This research may provide insight into the mechanisms behind the unique role of EPA and DHA and their role in supporting brain health,” she said.
”I look forward to all future research to better understand how increased intake of EPA and DHA can support brain health and have specific benefit for various populations.”
Source: Prostaglandins, Leukotrienes and Essential Fatty Acids, Volume 204, 2025, 102664, ISSN 0952-3278. doi: 10.1016/j.plefa.2025.102664. “Long-chain omega-3 polyunsaturated fatty acids are associated with brain connectivity and mood in young adults with subthreshold depression: A preliminary study”. Authors: P. Faulkner et al.
