One of the most accessible online resources about substance abuse gets down with a leading advocate of including yoga in treatment:
The Fix The Next Phase in Recovery—The Tommy Rosen Solution
Ninety minutes later, having come through an intimate and powerful experience, I would be directed to lie down, relax completely, and let the full weight of my body rest upon the earth. This was savasana or corpse pose. The feeling was electric—energy humming through my body. I felt like blood was pouring into areas of my tissues that it had not been able to reach for some time. It was relieving and healing. It was subtler than the feeling from getting off on drugs, but it was detectable and lovely, and there would be no hangover, just a feeling of more ease than I could remember. I felt a warmth come over me, similar to what I felt when I had done heroin, but far from the darkness of that insanity, this was pure light—a way through.