It's been known for a year or more than Sims can die from being over emotional. The example used was a Sim getting so angry it killed him.
But
you have the control.
http://www.thesimsresource.com/content/view-post/post/25898/page/5/***/5/
Emotions have intensity levels and believe it or not, EA confirmed that a Sim can actually die from its emotions! An example was that a Sim taken through the levels of anger through furious to enraged might result in them having what was described as something like a heart attack where they will break into such an animated rage that they keel over and die!
Speaking of which, EA have changed their philosophy on death for Sims 4. They realized that some things in previous games made death almost not fair and as funny as it was to die by having a satellite land on you from above, it just wasn't right. In Sims 4, death will only ever be a result of your actions, or age, and before a Sim does die from your actions, there will be plenty of warning signs before the event occurs! One thing for sure though; depressed Sims will not commit suicide! EA had no desire to 'gamify' tragic events.