This study is for people with depression that doesn't get better with regular medicine. It tests if omega-3 fatty acids (a type of healthy fat found in fish) can help improve depression by reducing inflammation (swelling and irritation in the body). Participants will be randomly assigned to take either omega-3 or a placebo (a harmless pill that doesn't do anything) for 12 weeks. The study will include blood tests and questionnaires to check for changes. Omega-3 may increase compounds that reduce inflammation and help with depression symptoms.

• The study lasts 12 weeks, and you'll need to take pills and get blood tests.
• Participants must be 18-65 years old with depression not improved by antidepressants.
• If you have certain medical conditions or take certain medicines, you might not be eligible.