Evidence related to nutritional metabolic deficiency disease lesions such as a history of malnutrition with niacin vitamin B1 and folic acid deficiency, signs and symptoms of nutritional metabolic deficiency leading to corresponding functional abnormalities, these can be used as diagnostic conditions for mental disorders associated with nutritional metabolic diseases. Vitamin B1 deficiency is associated with a variety of neuropsychiatric disorders, and the severe classic neuropsychiatric syndromes it causes are beriberi and Wernicke’s encephalopathy. The pathological changes are mainly from the papillary body hypothalamus midbrain aqueduct to the fourth ventricle and cerebellar cortex, such as left and right symmetrical perivascular endothelial cell hypertrophy sporadic hemorrhage, and mental retardation; if the reticular formation is involved, there is a disorder of consciousness; when vitamin B1 deficiency is accompanied by impaired glucose metabolism, brain edema can occur. Neurological symptoms are due to vitamin B1 deficiency when the brain and spinal cord congestion edema, degeneration, etc. The above changes are most prominent in peripheral nerves, limb nerves phrenic nerve terminal cranial nerves and vagus nerve terminal branches are also more susceptible to involvement, often peripheral neuritis nystagmus eye movement disorders, ataxia, occasional retinal hemorrhage, etc. The above serious cases are now less common. Niacin deficiency with mental disorders is also known as pellagra or Pellagra disease. There are many causes of niacin deficiency, such as inadequate food intake, chronic alcoholism and chronic diarrhea, etc. Niacin deficiency can lead to mental disorders caused by degeneration of the cerebral cortex, the basal ganglia of the white matter pituitary cells, and the posterior and lateral tracts of the spinal cord. It has been suggested that niacin is a polymethyl receptor and its deficiency can lead to increased catecholamine methylation products resulting in psychiatric disorders. In recent years, it has been reported that folate and vitamin B12 deficiency may play a dominant role in some psychiatric disorders, and a role for folate has been demonstrated in depression and similar schizophrenic disorders Folate deficiency may be associated with dementia in elderly patients with psychiatric disorders.