Actually, I DO allow for a non-physically harmful method of interrogation. Psychological trauma CAN be inflicted, and would certainly qualify as torture in my book, depending upon conditions. I try to keep things in perspective, and to some degree or another, situational ethics might very well apply.
I am only human.
When a person is duly convicted of a crime against others, as opposed to a crime against the state or a victimless crime, then he must be punished in accordance with the law and due process. I do not object to the death penalty, though the way we administer it leaves alot to be desired.
Sleep deprivation is torture, and an example of your non-physical (not entirely accurate, but suffices for discussion) battery.