i have seen someone recently go a bit berserk as well.

the person memang got mental problem. I wont say what kind of problem .

then what happen is the person pretend he is doing work. But no work come out.

So the IT decide to remote view the guys PC. end up is surfing net, watch porn ... so got dismissed. Stupid thing is they mention they view the PC. Somehow the guy kena hack and blame the IT and HR for the hack ... so got into big fight, got dismiss, still think he is right. Now I last heard the guy was seen walking near office premises, take photo of the IT guy ... wait near the guy's car, take picture, but never do anything. Like some crazy psycho fella.

I experienced the exact same person like this before, a very close person.

Yeah I know stress and depression is hard, but it's making the person who loves and cares for you even harder.

A psycho like this can easily drives his/ her closest person insane.

Cause the psycho strongly believe that everything he/ she experienced/ imagined is true, but as the closest person to the psycho you have to bear with all the bullshit and emotional torture the psycho is doing to you. Want to know how torture is it? Example:
If there is really a cockroach in your room, you spend time to find it and get rid of it so your gf can sleep.
If there is an imaginary cockroach in your room, you can't actually find it but you have to spend few hours per night doing stuffs to convince her that there is no cockroach so she can sleep then only you can sleep. AND YOU HAVE TO F*CKING GO TO WORK NEXT DAY and tomorrow night the same shit repeats.

Bring them to a doctor? It sounds much easier than actual, they will start calling you psycho instead. And after years of torture, you might become another psycho, or trying to kill yourself so you don't have to deal with this anymore.