A little addendum to my post yesterday about workplace psychos. Don't waste time thinking you can change their behaviour. It's that old story about the frog and the scorpion - it's what they do. Most workplaces have some sort of conflict resolution process in place and if you get dragged into one of these with your psycho by all means, participate in a positive way.
But don't fool yourself that anything is going to change. One of the key elements of a clinical diagnosis for a psychopath or sociopath is that they don't respond to treatment. You can't make them "better". They don't want to get better. So don't make yourself look bad by refusing to participate but don't harbour any illusions about the outcome.
To give an example from my personal experience, in one of my earliest jobs as a business analyst, there was one programmer who was clearly a psycho. Part of my responsibility was testing changes to the system before any changes went live and this programmer would get a tad fiesty when I delayed releases of his changes by doing crazy things like finding critical flaws. The process went a little like this:
Monday: I start testing changes he's made to the system. This is a script driven system used by operators in a call centre and it has to guide them through about 20 steps. The program falls over after the second step. It literally crashes and I can't continue. I file a bug report detailing the issue.
Tuesday: The programmer tells me the bug has been fixed and I should test it. Sure enough the bug has been fixed and I can get past step two. Then it crashes again at step five. I file a bug report. The programmer goes nuts and literally starts screaming. He tells the project manager it's my fault the code isn't ready on time because I should have told him about this second bug yesterday. The PM decides to calm the situation by taking us both off to another room to talk about the problem.
It took about five seconds to establish that the programmer was talking shit. Their whole beef was that I didn't tell them about this new bug yesterday. I calmly explained why it was logically impossible for me to have done so. I also was circumspect enough to not point out it was blindingly fucking obvious why it was impossible. The original bug happened at step two. The new bug was at step five. I couldn't get past step two to see the bug at step five until after the first bug was fixed.
As soon as it became obvious his bullshit was indefensible the programmer became nice as pie. He never admitted that his behaviour was totally fucked (let alone that blaming me for errors in his code at all was fucked) but he was suddenly the voice of reason. He actually said "Oh, why didn't you tell me that? I understand now. This was all a misunderstanding."
The PM asked if I was satisfied with the "resolution" of our discussion. I said yes even though I knew that no resolution had been reached, the smarmy git had simply weaselled his way out of the situation. It was clear to me there was no value in pursuing it so I said everything was OK.
A week later exactly the same thing happened. And I mean exactly. This same programmer started shouting and abusing me because I was doing my job (namely, providing evidence that he was shit at his job). The PM took me aside and asked if I wanted another "counselling session". I gave the honest answer:
"No, what's the point? You can see he's being unreasonable, if we go off and talk about it, I'll prove he's being unreasonable then suddenly he'll be all sweetness and light and promise this will never happen again. Then, next week, it will happen again. So long as you know he's being an idiot I don't really mind. I can ignore him."
In some senses, maybe I should have pursued it. He deserved to be fired but that would have involved making a formal complaint to HR and then a process that would drag on for months with this psycho kicking and biting every step of the way. And because of the small size of our team I would have had to keep working with him the whole time.
So getting rid of him was more painful than simply de-fanging him. He would still go apeshit from time to time but I had exposed him for what he was so he couldn't hurt me any more. So from my experience (and this is backed up by the reading I have done) it's unlikely you can actually change an office psycho. Don't waste time and energy on them, devote it to looking after yourself.