It's honestly a miracle he survived as long as he did. He was definitely a character and the man had his own so voice style that would be recognised straight away.
Dick van Dyke is still around at 97(!) in spite of many years of chain-smoking and alcoholism (he stopped drinking in his late 40s, and smoking in his 70s). Look, I like Dick van Dyke and I wish him many more years, but he ought to have died decades ago.
Biology is funny business.
As for ol' Dicky specifically, he seems to be doing pretty well for his age: https://www.youtube.com/watch?v=oL3AijekRYw
In Shane's case, is it any wonder that a chronic and extreme drinking problem eventually kills you? His quality of life has been impacted for almost as long as Keith Richards has been off the needle.
That's just too much irony.
Depressed and maybe borderline she was, but above all devastated by the preventible suicide of her son. (which is a huge story of Ireland's health service momumental fuckups on its own.)
Drugs just accelerate the melting mind process.