Mood Anxiety stuff has a ton of potentials, Hormones / Adrenals, NT's,
Toxins just as you cite esp Mercury (and
other Metals like Copper) & Cipro (and
other AB's) & Benzos (and
other Pharmaceuticals), too much Glutamate in Diet and
other nasties, many more, Gut again, oh the Gut I tell ya, I have yet to see a «sick person» with good Gut health.