Adding the clinical framing, because it changes how the question reads. The useful move here is to separate what is established from what is widely repeated. Those two sets overlap less than the confident tone of most write-ups suggests, and the second set is where nearly all the disagreement on this board comes from.

NicoleRaleigh said:

Say what you would expect to see if you were wrong, before you look.

That reframing is the part I needed.

From the other side of the consultation, briefly. The honest answer is that the effect is real, the magnitude is contested, and the individual variation is larger than either. Those three things can all be true at once, and most arguments here are two people holding different parts of that.

PedsEndoPhilly said:

The honest answer is that the effect is real, the magnitude is contested, and the individual variation is larger than either.

Mine went the same way, slower. Nothing to add that would improve it.

Moderator note: good thread. Keeping it here rather than moving it, because the question is general enough to be useful. Carry on.