This is what i think about mental health.

Don't you know that mental disorders are not 'just tumors.....'
It's an imbalance of the brain. Yeh, some guy might go and set an old lady on fire...there's lots of f***ed up people in this world. I really don't understand your logic. Sit down with someone you love, who has a mental disorder, and see what YOU see. By the sounds of it, you have no medical or legal knowledge.

Get a little knowledge before you make a #$#$#statement that's in your post. What do you know about the lobes of the brain? Which one is in charge of memory, behavior. Autism runs in families, so does schizophrenia.
The term for a sociopath is Antisocial Personality Disorder. Psychiatry is a science of the mind. Learn more before you decide what you believe.
Get an education about human behavior and then you can make an informed decision. Licensed professional here.
Now comes the nurture or nature talk. Some people are wired wrong, to put it simplistically. :roll

Tumors and such are not mental illness and the symptoms caused by them are not either. Mental illness is REAL!! I do agree with some of your thoughs about mental illness and crimes. Even with most mental illnesses one is capable of distinguishing between right and wrong. Crimes comitted by those in psychosis due to schizo or mania, assuming that their condition is lagit, do fit the catagory of being mentally incompatent as long as they were in an "episode" when the crime took place. Those who are in a stage of psychosis are unable to determine right from wrong. What makes mental illness so hard for the public to acknoledge is that to many criminals try to use it to get off the hook. Also that it is different than other conditions of the body in that it is not diagnosed and treated the same.