I can’t get the image out of my head of Robin Williams traveling around the world in spirit form looking for cocaine. It is my understanding that those who pass on with severe addictions–which in my view should be viewed as severe unprocessed traumas which have been managed during life by recourse to chemicals which mask the underlying illness–keep those addictions, and that he has as well. He never made it through the tunnel, or up the hill, however you want to frame it. He did not surmount the challenges set before him in this life.
Here is an interesting account of a death and rebirth experience (NDE does not quite fit the data), in which he talks about the fate of addicts: http://www.amazon.com/Return-Tomorrow-George-C-Ritchie/dp/080078412X/ref=sr_sp-atf_title_1_1?ie=UTF8&qid=1410961015&sr=8-1&keywords=return+from+tomorrow