"As soon as he started drinking, you could see a little smile on his face. That's when he could talk to people, or tell a joke." Coders in general are susceptible to alcohol for these kinds of reasons. Add in flexi hours (hey it doesn't matter what time I show up as long as I ship code, right?), and it's practically the ideal job for a functioning alcoholic. I've seen dozens of fellow programmers slip down the slope.…
Add in money and a tendency to have few friends, and almost certainly no SO, and the wonder is there aren't even more casualties. Though there are a huge number of people who get older and wonder where exactly it all went wrong.