Obtaining a second opinion never hurts. The description you provide does lead in the direction of PDD, and in many youngsters with a PDD diagnosis, OCD-type symptoms are prevalent and the child can display OCD alongside the PDD. The recommendation for medication is not surprising, even though your son is very young. When you use the term 'succumb' to characterize a possible decison to use medication, it implies that medication should be avoided. Try to regard it as a possible sensible intervention, though of course you never want to rush into the use of medication.