What is the name of this 'Sherlock Holmes themed' movie?

Factual Questions
1

I’m looking for the name of modern ‘Sherlock Holmes’ movie , seen within the last 20 years. The movie opens in a clinical setting, the staff watching
a group of mentally challenged teenagers getting their candy treats. A staffer notices that one boy always gets the M&M candies. Further review shows that he asks for M&M’s but is speaking in a mentally challenged voice. The staff suspects misdiagnosis. IIRC the hero solves some crimes and his nurse is Dr Watson.

Thanks
softie

2

Closed duplicate.

softie, your first thread was moved to Cafe Society. Look for it there. Do not open a new one.