If someone in the Secret Service’s care tries to commit suicide, what are the Secret Service agents assigned to protect them obliged to do?
Has this ever come up in the past?
There mission is to protect the President; they would attempt to stop him from harming himself.
There was a very recent thread on this. A much older thread and then this one are the ones I find doing a quick search.
Too bad you didn’t ask sooner, I actually met a Secret Service Agent serving jury duty two days ago. 
I don’t see it as being any different than other law enforcement. We get them the medical treatment they need.