D.M.T. is a vital part of the human brain, and inhibited by fluoride.

The primary reason fluoride causes such things is essentially Iodine Deficiency since Iodine chelates Fluoride, as well as heavy metals, then an increased consumption of fluoride whether in the water or toothpaste to the tune of 2.5 mg a day in an iodine-deficient population is a terrifying idea.

For instance things like Wilson's(having too much copper in the body.), or too much Iron, or too much Mercury which can result in neurological damage. Also after 220 days of exposure to Fluoride(brushing teeth and drinking tap water. Especially without a reverse osmosis filter.), you end up with a suppressed thyroid, which oftentimes can lead to manic episodes. Sudden cessation of fluoridated tap water, leads to a reduction of fluoride in the thyroid and increases thyroid functionality. However, since the majority of us had been exposed to Fluoride for an extended period of time. Then it causes hyperthyroidism which causes psychotic episodes.

This combined with developmental disorders associated with both Iodine and Fluoride deficiency, a lack of androgynous D.M.T. Leads to abnormal adolescent development, as well as a decreased I.Q. and abnormal hormonal development, including stunted or accelerated puberty.

Now the lack of androgynous D.M.T. is particularly important, as D.M.T. specifically allows for "abnormal" brain development within Mammals. While D.M.T. may genuinely be a bi-product within the Mammalian brain, it allows for "Synesthesia" (primarily spatial viso-memory synesthesia.) and or the healthy developmental cross-linking of "unrelated" regions of the human brain. This is what allows us to develop as intelligent and productive members of the human race. Not specifically to be tied to empathy, however beyond the fundamental need for D.M.T. within the human brain during all stages of development D.M.T. is also dangerous to some extent.

So all in all, the majority of Psychiatric issues facing people today are specifically to do with over fluoridation, D.M.T. deficiency, and Iodine Deficiency. D.M.T., specifically allowing for the key concept of the "self", threw which we identify or define "Self Awareness.".

D.M.T. increases neuroplasticity and your overall ability to think/learn, essentially facilitating creative thought, learning, productivity, and even allowing for things such as emotions, and empathy.

(D.M.T.: https://www.sciencedirect.com/science/article/pii/S2211124718307551 makes you smarter.)