That's how I was diagnosed--through a study. (My story here.) I've met many who experience cognitive issues with gluten contamination: brain fog, stumbling over words, forgetfulness, mood and behavior issues, etc; I'm one of them.
THIS STUDY (UCLA) reversed memory loss in 9 out of 10 patients with Alzheimers. Among the list of changes each patient in the study made, was eliminating gluten, 100%. Yes, this is a small study, but I see this as a big deal.