The problem still remains of how the physical measurements (even assuming we could measure them perfectly, which we definitely can't) relate to the internal experience.

Any real theory of psychology/neuroscience needs to be able to explain that, and currently I'm not aware of any that do.

> Psychology and psychiatry really do struggle to demonstrate statistically meaningful results behind most therapies (CBT is perhaps a notable exception, although even there results can be mixed)

So it's incredibly difficult to do good studies of therapy, because there is no simple placebo. All of the research I've seen suggests that there's huge amount of provider-level variance, which swamps the theoretically meaningful defences. I would suggest that this is because we don't really have a good understanding of how to interrogate our own (or others) psyches, which is definitely not something that neuroscience will help with (given the current state of the field, at least).