mental illness

mental illness   n.  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. Also called emotional illness, mental disease, mental disorder.

Main Entry: mental ill·ness
Function: noun
1 : MENTAL DISEASE
2 : a mental condition marked primarily by sufficient disorganization of personality, mind, and emotions to seriously impair the normal psychological and often social functioning of the individual called also mental disorder

Main Entry: mental illness
Function: noun
: MENTAL DISORDER

mental illness n.
Any of various disorders characterized chiefly by abnormal behavior or an inability to function socially, including diseases of the mind and personality and certain diseases of the brain. Also called mental disease, mental disorder.