well- stage IV? there is no stage V, unless stage V = death.
it would be incredibly suspicious in my case to refuse treatment and I have no doubt I'd be sectioned for doing so. not that it's outside the law to refuse treatment, but with my lengthy history as a psych patient, I wouldn't take that chance. I'd feign despair and smile and nod and agree that yes of course, precious life just must be preserved.
... and then I'd find 5 or more different connections and score a tonne from each one, and then I'd disappear. I'd go someplace far enough away, paying with cash whenever possible, find some dodgy motel to hole up in, and spend a few days playing my guitar, listening to as much music as I could, maybe reread my favorite book, indulge in one last very expensive bottle of scotch, one last carton of expensive cigarettes, I'd probably try to write down every thought I had, maybe stitch it all together in some patchwork poetic way. and then go out on one last high.