You are correct in your analysis. Quick data inquiry of medical/pharmaceutical research documents will reveal that scientists confirm that generic Concerta (Methylphenidate Extended Release) is a BIOEQUIVALENT, that is, the generic tablets have the same biochemical make-up of the Concerta, however the effectiveness of the proprietary delivery system (it is patented) of the Concerta is NOT part of the generic. The absence of the effective delivery system greatly reduces the generic Concerta efficacy. The FDA only certifies prescription generics on a basis of bioequivalency; not delivery.
What makes Concerta unique as an extended release is in fact the way the medicine is delivered throughout the day via a tiny hole in one end of the pill. This provides a slow dosage of the medicine over time, and greatly reduces side effects of headaches and loss of appetite since the medicine is not absorbed into the blood stream all at once.
CERTIFIED GENERIC CONCERTA will have the tiny end hole in the pill, as will name-brand Concerta. Do not accept any other generic prescription. You will have to advocate for this at the pharmacy, since many pharmacists will not be aware of this issue with the Concerta.
If you have not picked up by now, we had this issue with our daughter last fall. I am so sorry to hear your son’s gpa took a hit, but then the positive is that you found a medicine that is very effective for him.