From a psychological perspective, sometimes the demons that drive people to do great things also drive them to suicide. Many great historical figures have been hounded by depression including icons like Lincoln who often disappeared for periods of days (imagine a president who did that today) and suffered from paralyzing morbid depressions (even before he was a war president). I don't like sounding like a pharmaceutical ad, but there are actually organic imbalances that can trigger this. Unfortunately guys, especially macho ones like rock stars, often resist asking for help lest they see themselves a being weak. When it comes to suicide, there are two types...the ones like taking a bunch of pills and then calling your friends which are meant to be manipulative and then the guy type that is methodical and lethal, like Delp. The guys are more likely to "succeed".