Two studies were conducted to determine whether physical signs of fatty acid deficiencies such as dry hair and skin, frequent thirst and urination were a good indicator of whether fatty acid supplementation could potentially improve ADHD symptoms in children both with ADHD and those without the disorder. It was found that the physical symptoms of deficiency did not reliably predict which children would have behavioural benefits from supplementation.

abstract :Physical fatty acid deficiency signs in children with ADHD symptoms, Sinn N, Prostaglandins Leukot Essent Fatty Acids. 2007 Aug;77(2):109-15

Ref: food for the brain (+)