This happened to my son. He was actually misdiagnosed twice--once with ADHD/ODD and once with bipolar. He has Pervasive Developmental Disorder (PDD)-not otherwise specified or high functioning autism. The more independent the kids had to be in school along with the harder work load and organization, the further behind he fell. He is doing really well now, and has had lots of supports. I'd take her to a neuropsychologist for an evaluation. They do a great job of nailing down the problem areas and why they are problem areas. It's not, in our case, that cognitive abilities went down. It's that independent work and multi-tasking went up. My son needed help with that and had an aide for several years. He rarely uses her anymore, but still goes to Special Education one period every day. He is now in seventh grade and always makes the honor roll. He still has some life skill/social skill deficits that I expect will continue, but he's also much better with those too than he used to be.
