Mental insanity and Mental disease

Mental disease and mental insanity are semantically related in mental illness topic. In some cases you can use "Mental disease" instead a noun "Mental insanity".

Mental disease noun - Any disease of the mind; the psychological state of someone who has emotional or behavioral problems serious enough to require psychiatric intervention.

Mental insanity and mental disease are semantically related in mental illness topic. You can use "Mental insanity" instead a noun phrase "Mental disease".