Here's what I think happened, based on my not-unimpressive experiences with psychiatric meds. After years and years of depression I was finally switched to Zoloft (years and years ago) and, in a bit, began to feel a sort of euphoric equanimity with matters mental. I felt "normal," as it were, and so glad. So glad I thought, this is almost heaven! and began not-unserious plans to kill myself straightaway, before that feeling could go.
Still here, but I can't help but consider Chris had reached that same peaceful equanimity, and did want ever to let it go.