Definition Psychiatric disorders:any of various conditions characterized by impairment of an individual's normal cognitive,emotional, or behavioral functioning,and caused by social,psychological,biochemical,genetic, or other factors,such as infection or head trauma.Psychiatric disorders ：any of various conditions characterized by impairment of an individual's normal cognitive, emotional, or behavioral functioning, and caused by social, psychological, biochemical, genetic, or other factors, such as infection or head trauma. Definition