'The crazies' as in mentally unstable were at their peak in BB7. Leah had body dismorphia, Nikki was still dealing with anorexia, Dawn had issues, Shabaz had majour issues, claiming he would kill himself in the house.

I think Sezer also had some issues and Pete to some extent aswell.

BB5 may of been out there, but BB7 had some extremely vulnerable people. TV GOLD! lol.