A multi-national, multi-disciplinary Delphi consensus study on using omega-3 polyunsaturated fatty acids (n-3 PUFAs) for the treatment of major depressive disorder

Introduction: Omega-3 polyunsaturated fatty acids (n-3 PUFAs) are recommended as an integrative treatment for major depressive disorder (MDD). In 2019, the International Society for Nutritional Psychiatry Research (ISNPR) developed the first practice guidelines for n-3 PUFA treatment of MDD. To strengthen these guidelines and enhance their clinical applicability, we synthesized the evidence and clinical experiences previously obtained through the Delphi methodology. Methods: Nineteen statements covering five major domains in MDD treatment were formulated through internal meetings. Fourteen international experts were invited to participate in the web-based Delphi process that validated the statements. Likert scales were used, and consensus level was set at 7.0/10.0, with the equivocal level set at 5.1–6.9. The items with scores < 5.0 were allocated into a second round Delphi survey with inverse questions. Results: All panelists completed the survey. Sixteen statements reached consensus, and the statement “n-3 PUFAs are one of the potential adjunctive treatments for adult MDD” reached the highest agreement. “N-3 PUFAs are one of the potential monotherapies for adult MDD” instead scored lowest. Regarding “special populations,” many items, reached high consensus despite sub-optimal supportive evidence. Limitation: The panelists had a specialized interest in n-3 PUFAs; focus was placed on clinical issues rather than on biological mechanisms. Conclusions: The Delphi process helps bridge the gap between scientific evidence and clinical practice, supports certain uses of PUFA and identifies insufficiency in current evidence that merit future research.