2026-01-15
Depression: What if the solution were on the plate?
Addictology
By Ana Espino | Published on January 15, 2026 | 3 min read
Major depressive disorder (MDD) is one of the most common and disabling psychiatric disorders worldwide. It affects quality of life, increases suicide risk, and represents a heavy burden on healthcare systems. Although conventional antidepressants are the first-line treatment, their effectiveness remains partial and inconsistent, with non-response rates estimated at 30–50%. In addition, management is often limited by side effects, delayed onset of action, and poor adherence.
In this context, the search for complementary or alternative therapies has become a major issue. Omega-3 fatty acids, particularly EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), have emerged as promising therapeutic candidates due to their anti-inflammatory, neuroprotective, and neurotransmitter-modulating effects.
However, clinical trial results have remained heterogeneous, limiting their inclusion in guidelines. The objective of this systematic review and meta-analysis was therefore to synthesize the available data on the efficacy of omega-3s in the treatment of adult MDD, assessing reductions in depressive symptoms, remission rates, and adverse effects.
Twenty studies published between 2000 and 2022 were selected. The analyzed body of evidence included 15 randomized controlled trials (RCTs) and 5 observational studies, totaling more than 2,300 adult patients diagnosed with major depression according to DSM-IV or DSM-5 criteria.
The analysis examined the effectiveness of omega-3 supplementation, alone or in combination with conventional antidepressant treatment. Primary outcomes were changes in depressive symptom severity measured with validated scales (HAM-D, MADRS), remission rates, and tolerability.
The results show a significant reduction in depressive symptoms in patients receiving omega-3s compared with placebo (Hedges’ g = −0.45; p < 0.01), indicating a moderate but clinically relevant effect. The effect was more pronounced in patients with moderate to severe depression and in those receiving EPA combined with an antidepressant. EPA alone, at doses above 1 g/day, appeared more effective than DHA or EPA/DHA mixtures. Side effects were rare and mild, mainly gastrointestinal (nausea, diarrhea).
Major depressive disorder is a chronic, multifactorial condition that is often resistant to standard treatments. One current challenge is to enrich the therapeutic arsenal with complementary, well-tolerated, and accessible approaches, particularly for moderate to severe forms or relapse prevention.
This study aimed to clarify the role of omega-3s in this management. It shows that supplementation—especially EPA—is associated with significant improvement in symptoms, particularly as an adjunct to conventional treatment. It thus supports the value of an integrated nutritional strategy within the global management of the depressed patient.
However, limitations remain and justify further research. Key weaknesses include heterogeneity of formulations, variability in doses and treatment durations, uneven study quality, and a lack of long-term data. It is now essential to define patient profiles most likely to respond, optimize dosing, and standardize omega-3 extracts in trials. Future work should also better explore the differential impact of EPA versus DHA, as well as the integration of omega-3s into personalized care protocols.
Read next:
Major depressive disorder (MDD) is one of the most common and disabling psychiatric disorders worldwide. It affects quality of life, increases suicide risk, and represents a heavy burden on healthcare systems. Although conventional antidepressants are the first-line treatment, their effectiveness remains partial and inconsistent, with non-response rates estimated at 30–50%. In addition, management is often limited by side effects, delayed onset of action, and poor adherence.
In this context, the search for complementary or alternative therapies has become a major issue. Omega-3 fatty acids, particularly EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), have emerged as promising therapeutic candidates due to their anti-inflammatory, neuroprotective, and neurotransmitter-modulating effects.
However, clinical trial results have remained heterogeneous, limiting their inclusion in guidelines. The objective of this systematic review and meta-analysis was therefore to synthesize the available data on the efficacy of omega-3s in the treatment of adult MDD, assessing reductions in depressive symptoms, remission rates, and adverse effects.
Omega-3s against low mood?
Twenty studies published between 2000 and 2022 were selected. The analyzed body of evidence included 15 randomized controlled trials (RCTs) and 5 observational studies, totaling more than 2,300 adult patients diagnosed with major depression according to DSM-IV or DSM-5 criteria.
The analysis examined the effectiveness of omega-3 supplementation, alone or in combination with conventional antidepressant treatment. Primary outcomes were changes in depressive symptom severity measured with validated scales (HAM-D, MADRS), remission rates, and tolerability.
The results show a significant reduction in depressive symptoms in patients receiving omega-3s compared with placebo (Hedges’ g = −0.45; p < 0.01), indicating a moderate but clinically relevant effect. The effect was more pronounced in patients with moderate to severe depression and in those receiving EPA combined with an antidepressant. EPA alone, at doses above 1 g/day, appeared more effective than DHA or EPA/DHA mixtures. Side effects were rare and mild, mainly gastrointestinal (nausea, diarrhea).
EPA, a discreet ally of mood?
Major depressive disorder is a chronic, multifactorial condition that is often resistant to standard treatments. One current challenge is to enrich the therapeutic arsenal with complementary, well-tolerated, and accessible approaches, particularly for moderate to severe forms or relapse prevention.
This study aimed to clarify the role of omega-3s in this management. It shows that supplementation—especially EPA—is associated with significant improvement in symptoms, particularly as an adjunct to conventional treatment. It thus supports the value of an integrated nutritional strategy within the global management of the depressed patient.
However, limitations remain and justify further research. Key weaknesses include heterogeneity of formulations, variability in doses and treatment durations, uneven study quality, and a lack of long-term data. It is now essential to define patient profiles most likely to respond, optimize dosing, and standardize omega-3 extracts in trials. Future work should also better explore the differential impact of EPA versus DHA, as well as the integration of omega-3s into personalized care protocols.
Read next:
About the author – Ana Espino
As a scientific writer, Ana is passionate about bridging the gap between research and real-world impact. With expertise in immunology, virology, oncology, and clinical studies, she makes complex science clear and accessible. Her mission: to accelerate knowledge sharing and empower evidence-based decisions through impactful communication.
PhD in Immunology, specialized in Virology
Last press reviews
Microbiota & Alcohol: toward a new treatment?
By Ana Espino | Published on January 13, 2026 | 3 min read<br>
Alzheimer’s disease & alcohol: a toxic duo for the brain?
By Ana Espino | Published on January 12, 2026 | 3 min read<br>