man i thought this was an achewood thread at first haha ;_;
i know way too many dudes (practically lived with em) who fit most or all of the kinda categories your friend pat fell into. dudes who'd get all worked up on whatever substance and as soon as they were sober they'd be incredibly friendly, apologetic, and do whatever they could to make reparations for anything they messed up on their imbibing spree (when they remembered what they'd done at any rate)
the longest i've known some of them is about seven years, and none of them are dead that i know of, but most of them are easily on their way due to their party all the time lifestyles
the biggest thing i hate is that it's become difficult to trust a lot of them, their addictions have gone from plain mary jane to straight up cocaine in some cases, it's heart-breaking to contrast what they used to be (well-read pot smoking hippies) with what they are now (semi-cognizant rotting rice on the shelf co-sign this for me i'm outta cash addicts)