Alireza Amirsadri, a Wayne State University School of Medicine psychiatrist who studies Seasonal Affective Disorder (SAD), said that fish and fish oil supplements are some of the means used to offset depression and heart disease. While no conclusions have been reached yet, doctors recommending the supplements say evidence is building that fish and fish oil supplements work to protect your heart and improve your mood. "Fish oil is good for many reasons including cardiovascular and cognitive preventive measures," said Amirsadri. "It is a mood modulator and reduces anxiety and depression or even manic symptoms."