What would be the difference between childhood disintegrative disorder and other similar types of conditions, such as autism, or schizophrenia? Is age and pace of onset the only criteria? what about eeg, ct, or MRI studies?:scared:
Age of onset would certainly be the differentiating factor for Step 1 purposes: autism the earliest, child disintegrative disorder between three and adolescence, and schizophrenia from adolescence onward. Autism is more likely to be a male child.
Since they are all syndromal and of still-uncertain etiology, no laboratory tests can rule any of those in or out, recent research notwithstanding. You'd want to do EEG to rule out seizure disorder, Landau-Kleffner, etc. You'd want to rule out lead poisoning. You might use MRI or CT to rule out lesions, hydrocephalus, etc. Lab tests could separate some the genetic developmental disorders out, ie Prader-Willi or Angelman's in a very young child with developmental arrest, Rett's syndrome in a slightly older girl, etc.
I think for Step 1 questions they'd give some extra hint if they really wanted a diagnosis. Hope this helps!