Eighties pop singer Debbie Gibson has warned Justin Bieber  to slow down on his rise to superstardom, because he will "lose his  sanity" if he fails to stay grounded. Gibson became a teen sensation  after the release of her single "Shake Your Love" in the 1980s and she  credits her mother's guidance with helping her to avoid the pitfalls of  fame. 
But she worries Bieber, 16, is taking on "too much too soon" - and fears his hectic schedule will cause him to crash and burn when he's older.
  She tells Eonline.com, "People have to remember even though a kid can be  wise beyond their years professionally and can handle showbiz,  emotionally you're not developed. Somebody has got to remember that  Justin is 16. (If he doesn't stay grounded, he will) lose his sanity  (later)."
But she worries Bieber, 16, is taking on "too much too soon" - and fears his hectic schedule will cause him to crash and burn when he's older.

