The brain is the organ that produces mental activity, and modern neuroscience has proved that normal brain structure and function can produce normal mental activity, and vice versa, abnormal mental activity can occur. If the cognitive function of the frontal lobe is harmed, the patient will have difficulty in completing complex actions in time and space; the lack of vitamin B due to alcoholism causes damage to the medial thalamus and papillary body, resulting in patients with near-memory disorders and orientation disorders; magnetic resonance (MRI) scans have found that the thalamus of schizophrenia patients is smaller than that of normal people, which may be one of the reasons for the occurrence of hallucinations during the onset of the disease. Neurobiochemical studies of the brain also revealed that positive symptoms such as hallucinations, delusions, and behavioral disorders in schizophrenic patients were associated with hyperfunction of dopamine (DA) in the subcortical limbic system, while negative symptoms such as impoverished thinking, emotional apathy, and lack of volition were associated with low DA function within the cortex, especially in the prefrontal cortex.Reduced function of 5-hydroxytryptamine (5-HT) was also associated with depressed moods in depressive patients, appetite, anxiety, circadian rhythm disruption, insomnia, decreased activity and sexual dysfunction. In addition, there are only 30,000 ~ 40,000,000 human genes, but under the effect of learning and training, experience accumulation and external environment, it can form several trillion to more than one trillion synaptic connections, indicating that the human brain has great plasticity, which also provides a therapeutic basis for drug therapy and psychotherapy.