MG talking from a personal experience, I did my internship in a state (mental) hospital and my job was to stand at the background and merely observe :p Seeing some of the patients there, I would definitely call unstable state of mind as mental disease. One gruesome incident, one man killed his mom and took an organ out and wrapped it in a plastic coz he had visions that the devil wanted his mom's heart and he was hiding it under the bed so that it could not be stolen. If this isn't madness, I don't know what it is!! Another experience, a friend of mine flipped his mind and had to be taken to the mental institute, later on he recoveded after medical treamtment but I don't think he will ever be the same again. American societies tend to over-exxagerate mental illnesses. I heard this talk program where coz the teachers in public schools cannot control their unruly students, so they refer them to the school counsellor who label them as ADHD. No wonder US has the highest rate of mental patients!! Some ppl misuse mental illness by using "Temporary Insanity" as an excuse to escape from prison, if they are lucky enough they get out scot free. One of the doctor there told me that only 1% of the patients use mental illness to escape prison and among them only 0.03% are actually put in hospitals. Don't know how much of that is true. Opppppppppps the post is kinda long.