"Is that the only reason you have to do it?" Even as he asked it, Sam was afraid the answer was yes. That Cas really didn't have any drive, or want, or hope within him to make the decision for himself. At least, not that he could access underneath the drugs.
He didn't meet Cas's eyes. He didn't want to cause his friend pain, and there would undoubtedly be pain, from the physical and emotional withdrawal. He didn't want it on his head, but... if it was the only way to push Cas towards taking care of himself, then he had to take it.
His eyelids flickered, looking down at the floor. He shifted his weight, and adjusted his shoulders to bear up under the weight of the guilt that he was signing himself up for. "Alright, then. For my sake."
He didn't look up. He hadn't even bothered to argue about the nickname.