Fish Oil  Studies show that omega-3 essential fatty acids (EFAs) may stimulate brain and nerve function, improving ADHD symptoms such as focus and hyperactivity in some patients. Outside of sardines, tuna, and salmon, the best source of EFAs is a fish-oil supplement with roughly a 4:1 ratio of EFAs to omega-6 fatty acids (DHAs) Adhd Diet, Adhd Brain, Trouble, Fish Oil