From the article:
"They said he had undergone heart surgery a year ago and was on several medications as a result."
When I hear things like this I wonder what effect his cocktail of drugs had on his mental state. No matter how much testing drugs undergo, we don't know specifically how a drug will affect an individual, nor is there testing done on the synergestic effect of each drug combined with every other drug a doctor may prescribe to one individual. A drug by itself may be ok, but combined with another drug or multiple other drugs, or with the specific chemistry of an individual, may have distrastrous results.
Drugs, whether on the street or in the doctor's office, are potentially dangerous.
Heart surgery also causes depression in many cases. It's not always the drugs especially if his doctor was still observing him.