Amino acids in large doses could I think be classified as Orthomolecular Psychiatry or the targeting of illness via Nutritional methods.
Amino acids are known to increase the production of neurotransmitters within the Brain and cure mental health problems.
This was also the experience of Dr Abram Hoffer in his treatment of schizophrenia with large doses of Vitamin B3.
You may be interested to know that Dr Yuri Nikolayev of the Moscow Psychiatric Institute, successfully treated Schizophrenia with up to 30 day water only fasts, enabling his patients thereafter to resume normal lives.