The omega-3 polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are found in oily fish. Researchers from the National Institute of Health Research (NIHR) Maudsley Biomedical Research Centre assessed the effects of high doses of EPA and DHA in lab-grown neurones and then in patients to help clarify how they reduce inflammation and depression. This novel approach allowed the scientists to identify an important molecular mechanism which can help inform the development of potential new treatments involving omega-3 fatty acids for patients with depression.