She's Hearing Voices Lyrics

Lyric discussion by beitbe 

Cover art for She's Hearing Voices lyrics by Bloc Party

I've a impression it's about someone (probably the narrator himself!) who is getting out of control (bad trip) after using too much of some psychedelics, and starts feeling some uncontrollable fear, remembers earlier warns from friends, etc, is having signs something is going wrong ("She's hearing voices call her, She's hearing voices warn her"), and took a lot of it:

"She got a red pill, blue pill Red pill, blue pill" (x14)

in the last part, there's some confusion between "she" and "I", maybe a reference to some dissociative (despersonalization) effect of the drug, maybe he couldn't remember who he/she was ("milk of amnesia", a reminiscence of his 'sober' consciousness telling him what could help him put it away "milk of magnesia", a laxative, but he couldnt figure it out during the bad trip). The confusion of mind progresses and at the very last he doesn't know even if he's alive ("I'm tearing down posters, I was never ever alive.")