I do have experience with those diagnoses. I do not know her DS of course, but I find it pretty difficult to diagnose any 6yo with ODD. I am not saying you can't or that I haven't. That diagnosis could very well be accurate and I have never met the child...but it is tough to tell at that age whether there are other factors causing a child to be that oppositional. A lot of kids that age are oppositional and behaviors could be related to PDD-NOS and difficulty expressing himself causing him to act out more. Depression easily goes along with ODD and PDD-NOS. Chances are that depression will go away when he is able to communicate things better...as could the ODD as well. Sometimes psychiatrists diagnose without thinking through what all those diagnoses will do to a parent, and how overwhelming it all can be for parents. Remember that they are categories that they feel the child fits into and that unfortunately due to insurances there has to be a diagnosis in order to treat and for the child to get services they need. Hopefully some of those diagnoses will go away in time and the child will be happier and more successful at school and at home. I wish your friend and her son the best of luck.