It is possible, It can take a lot of work, trying to find the cause and fix it, but I have treated many successfully.
About Dr. Mary Ann Block
Dr. Mary Ann Block is Medical Director of The Block Center, an international clinic for the treatment of chronic health problems in children and adults. She is an international expert on the treatment of ADHD without psychiatric drugs. Her approach is to look for and treat the underlying problem instead of covering the symptoms with drugs.