The last time was his July 2007 motorcycle accident when he wasn't wearing a helmet and his head hit and scraped the pavement. That's the picture at left. He was lucky it wasn't a lot worse.
But that luck may have been only partial. We have been hearing a lot lately about the concussions that damage the brains of football players. Today I read an article in Scientific American that says that even mild concussions raise the risk of depression and suicide three times or more.
A Single Concussion May Triple the Long-Term Risk of Suicide
They don't know what the mechanism is, but the evidence is clear, that even mild concussions cause brain damage that has severe consequences.
Maybe in Leif's case, he might have been able to handle any combination of all the problems he faced if he hadn't had the head injuries, or the asthma, which bothered him greatly. Both head injuries and asthma are also associated with depression. Several studies have shown a link between asthma and increased suicide rates, too, particularly with severe asthma.
Too many risk factors for one man to escape.
Who knows, maybe without the injuries and the asthma, he would still be alive.