Further, the mere existence of the Placebo Effect is evidence that naturalism (which you seem to profess) is wrong. The Placebo Effect could not exist in a purely naturalistic universe where all operates on cause/effect. Given that that placebo has no causative powers, there is no effect possible. And yet the one taking it believes there that powerful medicine is at work, so there is a change (and this has been seen in profound areas like Parkinsons Disease symptoms being reduced by simply believing in the sugar pill). This points to an unembodied consciousness with the ability to impact the physical body.
Look, if it makes you believe something, then it has already *caused* a physiological response in your brain. It had an *effect*. On your physiology. So there are changes. Complex changes that we don’t fully understand, sure, but that’s not an excuse to invoke magic.
I don’t understand your assertion that the placebo effect couldn’t work in a purely naturalistic universe. There’s a range of fully-functioning explanatory principles, some biological and some psychological, that explain much of what occurs during the so-called “placebo-effect.” It’s no more magic now than colds and flu’s were before we fully understood germ-theory. Much-like the later mentioned near-death experiences, there are some things we don’t know, but this isn’t proof of god, only that there’s things we don’t know, something any good scientist or skeptic will fully admit. “I don’t know” is a fully acceptable answer if we don’t currently know (hopefully followed by “how can we find out?”) However, “I don’t know, therefore God” is just intellectually dishonest.
There is an excellent book about the placebo effect, whose title I forget at the moment, but the effects are shown to be entirely because the person believes it will happen. Thus the placebo effect is more effective in cases where the problem is physiological such as asthma. It isn’t so good in killing bacteria. In other words – we report we feel better because we think we should be feeling better.
Overall, there's a couple of points which you don’t seem to have considered:
1. Placebos don’t work on everyone. 2. Nocebos affect people negatively.
This isn’t good news for your unembodied consciousness. Apparently it’s choosy and mean. It never heals amputees. What does your unembodied consciousness have against amputees?
I think the placebo effect points to the brain, and how much we don’t know about it. Put it this way: Ever distracted a child that has skinned her knee? Notice how she stopped crying when her attention was fixated on the promise of ice-cream? No gods needed.
Yes, people’s beliefs, moods and attitudes can have an impact on their health. If they believe they’re receiving effective treatment their mood will improve, stress hormones reduce, they take better care of themselves etc. That’s without invoking explanations like regression to the mean and so on.