It is pretty clear from case reports (from patients, not MD's).

Endocrine problems, especially poor stress tolerance: brain.

Emotional volatility, difficulty teling what people are about: brain

Difficutly getting along with people, attention deficit: brain

Brain fog is about 70/30 body/brain. Mostly it does go away even without
brain detox.

Yeast is actually a brain related problem (it is controlled by inadequate
hormone levels, especially hydrocortisone) and while it improves with body
detox, it doesn't go away until the brain is cleared if it is a real bad
case.

Allergies, food sensitivities, chemical sensitivities do mostly go away
with body detox.

Fibromyalgia seems to be mostly body tox. Chronic fatigue seems to be about
70/30 body/brain.

Andy Cutler