Torture without physical pain
Yuletide done, so now it's time for NaNo. Why can't they have a writing event in, oh, say, April?
The question: I'm looking for little known torture techniques that don't cause physical pain (little known, because research has been helpful so far in providing the big ones). Alternate universe that's nearly identical to current universe technology-wise; modern times.
Limitations: the character needs to be in acceptable physical and mental health after he's broken so that he can be used by the government. He's a serious self-mutilator (which is why the bad guys aren't even attempting physical pain torture -- anything strong enough to overcome his current pain tolerance would probably cause permanent injury), underweight (so starvation is out), deaf, highly isolated (so shunning is out), and has no known phobias. The techniques I've already found involve rape, sleep deprivation, and sensory deprivation. Is there anything else ya'll can think of?
(Note: I have considered Chinese water torture, but that seems a little crude for modern torture. Unless it's really effective, in which case I can shiny it up.)
ETA: I've got what I need (I could torture *twenty* people with all my new knowledge:) Thanks!