mental disease

noun | mental dis·ease

1. : an abnormal mental condition that interferes with mental or emotional processes and internal behavioral control and that is not manifest only in repeated criminal or antisocial conduct; broadly : mental illness : mental illness

   Note: Mental disease and mental illness are in general use synonymous, but mental disease has developed a settled meaning in criminal law while mental illness is often explained or defined by reference to the medical community's understanding of the term.