Isoniazid is a powerful anti-tuberculosis drug, but has obvious toxic side effects on the central nervous system and peripheral nerves; n Psychiatric symptoms mostly appear when the total amount reaches 20 grams or more during treatment, and its incidence is 1-2%; n The acute phase manifests as involuntary muscle tremors, slurred speech, and blurred consciousness; there may be rich and vivid visual hallucinations (seeing poisonous snakes, fierce animals, ghosts and monsters), and the content of auditory hallucinations with The content of auditory hallucinations is threatening and intimidating. Delusions of guilt and persecution are common; some patients, on the contrary, have emotional indifference and emotional retardation.