It didn't take long for Mario to realize that Angus was abusing drugs. After Angus responded to the accusation with anger and denial, Mario turned to Angus’ brother, Mike.
When confronted by Mike after the ER came out of Code Black, Angus admitted that he turned to Adderall after Malaya's attack. In a very powerful moment, Mike assured his younger brother that they would find help. He also reinforced that Angus was still a good person and an amazing doctor.