I've used the MASC in the past. I find it to be more useful with younger children than with adolescents. I do also find it underestimates anxiety symptoms in children who are particularly not introspective, or who are reticent (e.g., those on the autistic spectrum, those who are more withdrawn, those with some dissociative/detached qualities).
Remember that a diagnosis should never be made based on a single data source.
This is exactly what I was wondering, thank you--especially because of the ASD, withdrawn, dissociative/detached qualities.
I've also found professionally that I can work with an adolescent with ADHD or relational difficulties, for instance, for months before finally "stumbling" upon anxiety (after much rapport building). This makes me consider my approach.
I think there are some implications for DS' treatment plan, both medical and psychological. Knowing what we need to address seems pretty critical. I would have described DS as highly (but atypically) anxious and also depressed. Evidently, he does not self-report these symptoms (on MASC or CDI), but I'm guessing it's a matter of his answering kind of A) in the moment and B) not introspecting...at all.
