Mental disorders can be broadly divided into two categories, organic mental disorders, which means that the cause can be found, and functional mental disorders, which means that the cause is not clear, but only classified according to the symptoms of mental disorders. The main mental disorders are dementia and other organic brain mental disorders, epileptic mental disorders, mental disorders due to central nervous system infections, mental disorders due to somatic infections, mental disorders due to cranio-cerebral injuries, and mental disorders due to intracranial tumors. Psychiatric disorders due to somatic diseases, such as hyperthyroidism, hypothyroidism, cirrhosis, and pulmonary failure. There are also alcohol-related psychoneurological disorders, such as psychiatric symptoms due to alcohol dependence and alcohol withdrawal. There are also psychiatric disorders caused by psychoactive substances, which are generally drugs. There are also toxic psychiatric disorders, such as carbon monoxide poisoning after the patient can have psychiatric abnormalities. There are also schizophrenic disorders, schizoaffective disorders, paranoid disorders, mood disorders, neurotic disorders, including anxiety disorders, obsessive-compulsive disorders, etc. There are also psychogenic psychiatric disorders, such as post-traumatic stress reaction, and psychiatric disorders closely related to culture, as well as psychological and physiological disorders and psychosomatic disorders, personality disorders, psychosexual disorders, mental retardation, organic psychiatric disorders in children, child-specific developmental disorders, such as autism, and mood and behavior disorders in childhood, such as tic disorders.