besides dru was'nt nuts before she was a vampire . she church going and I think she was an early psychic and had visions which her parents probably thought they were the work of the devil . and angel sired dru and then drove her nuts. and then dru sired spike which calmed her down.
No, you got it backwards. Angel said he first
drove her insane. Then he sired her.
Angel: I did a lot of unconscionable things when I became a vampire. (turns back, but doesn't make eye contact) Drusilla was the worst. She was... an obsession of mine. She was pure and sweet and chaste...
Buffy: And you made her a vampire.
Angel: First I made her insane. (looks at her) Killed everybody she loved. Visited every mental torture on her I could devise. (Buffy looks away) She eventually fled to a convent, and on the day she took her holy orders, I turned her into a demon.
("Lie to Me")
She already seems out of her mind in the church flashback in "Dear Boy" (not "Darla" - thanks, Ethros...).