Yes, omega-3 fish oil, particularly the EPA (eicosapentaenoic acid) component, has been shown in several studies to support mood and reduce symptoms of depression in some people. It's often used alongside prescribed treatments, not as a replacement. Some individuals may notice benefits after a few weeks of regular use. However, results can vary from person to person. If you're dealing with depression, it's essential to consult a doctor before starting any supplement to ensure it's safe and suitable for your condition.