Kalie Marchado, former assistant to pop singer Britney Spears, wants her to seek "mental help".
Marchado worked for Spears for three months from January and says she was shocked by Spears' strange behaviour after she split from Kevin Federline.
Contactmusic.com quotes Marchado as saying: "She's very, very nice, but she has crazy thoughts always going through her head.
I never saw her do drugs. I never saw her take prescription medicine - but she needed it. She needs mental help."