Hello, I am wondering if there is an actual hypo version of Attention Deficit Disorder? My son is 21 and has struggled his whole life with lethargy, even as a toddler. We ve been told he has Aspergers/Autism, a milder form. But, as a former teacher, I noticed early in his life that it felt like he had ADD with lethargy. He s had many tests done, including endocrinology tests for his thyroid and endocrine system, blood work panels, and even a sleep study that lasted for 24 hours. Everything is normal . If there is such a diagnosis of ADD with HYPO behavior, is there a way to get that diagnosed and with what type of doctor? Thank you, Kathy