Of course Hungtington's and addiction are in different catagories, but I strongly believe that genetic makeup plays a role in each. An addict won't automatically grab for heroin, a drink or some other poison but there has to be a reason why I can handle a drink or two but it becomes the start of a binge for a friend of mine. Yes, there is a choice involved, but there are also urges that are too strong for some people to handle without help.

As for why some artists can handle it and others can't, I think that also can be traced to genetics.   Why is Keith Richards still walking the earth and Gram Parsons gone?

I do agree, JT was a very moving part of the documentary. He has inherited his father's gift of eloquence, and it appears he has a good head on his shoulders.