Here's a list of symptoms on MPD/DID from http://www.webmd.com/content/article/118/112901.htm:

Also of interest to me was the info on "Depersonalization" disorder:

The "the person might feel like they're a robot" thing made my eyes pop out. 

There is one close person from my past who I suspect might've been involved with the MC stuff.  I'm unsure.  I know his father abused him regularly (I remember hearing it once when I slept over); he was put on anti-psychotics when we were 12; he was obsessed with dark occult magic from a young age; he told me about having sex with cousins around age 5 and upwards; he wanted to be turned into a vampire--he was INTO the vamp thing, watching every movie over and over; he was masochistic, cutting on himself; his personality was malleable: he would emulate this idol and then that idol; he believed it was his mission to be an anti-Christ of sorts; his father--since I was a toddler--has always given me the creeps, still does.  Also, just remembered this: when I became interested in magic around 14 or so, he'd come over and want to do magic with me but always wanted to reverse the suggestions of any spell from a book I had (which was mostly white or grey magic).  If the spell called for bathing in cold water as a preparation, he'd say "Let's do it in hot."  If it called for white candles, he'd say "black."  And on and on.  He's also blue-eyed and blondehaired. 

I last saw him in the summer of 2004.  He has three gorgeous blue-eyed, blondehaired children now.  He acted kind of petulant with me because I hadn't called him in years.  It sounded like he had a very boring life.  The last time I saw him before that he was running fake-check-cashing scams and talking about starting a gang that would take over the world and had a friend who thought they could build a rocketship to Mars.