By now, you may have noticed the term “Omega-3” showing up all over the place — on your orange juice carton, on your cooking oil, even in some pet foods. Research on the health benefits of omega-3 oils (found in fish oil) has been piling up for over 20 years. Some studies have shown that fish oils aid in the treatment of aggressive behavior, ADHD, and autism spectrum disorders.
Here are some links to some studies on ADHD and fish oil supplements:
The most commonly reported side effects of taking fish oil are loose stools and fishy burps. For more information on fish oil and the health benefits of Omega-3, the Omega-3 Wikipedia page has a good overview and links to many more sources and scholarly articles.