No, although I'm assuming severely mentally ill, being capable of thinking "this is bad and/or weird, I shouldn't be doing this" and doing it anyway would constitute responsibility for the action.


But this brings up a problem, now that Mr P. has brought up psychos. Mentally Ill = not responsible. But what about murdering Psychopaths? If they lack empathy because of how they were born/raised (both through no fault of their own),  I would consider them to be too, not responsible for a criminal actions such as murder...or putting a cat in a microwave. By all means a psychopath should be categorized under mentally ill as they didn't choose to lack empathy; that is what a true criminal would do.