Mental illness can be clearly detected. Mental illness is a condition in which the mental aspects of a person and most normal people have significant behavioral abnormalities, showing differences in cognition, emotion and behavior. The main judgment of mental illness relies on the patient’s medical history, which is mainly provided by the patient or surrounding colleagues, family members, friends and relatives, providing that the patient has obvious abnormalities in speech and behavior. There is also a detailed psychiatric examination or psychological assessment that can be performed after arriving at the hospital. According to the psychiatric examination by a professional psychiatrist, excluding other related physical diseases, a person can be clearly diagnosed whether he or she is suffering from a mental illness.