NEW YORK — While many girls dream about Justin Bieber at night, the singing sensation is struggling to fall asleep.

The 16-year-old tells Vanity Fair magazine that sometimes he suffers from insomnia. Bieber says his "mind races" at night and it happens because he begins to "think about all the things I didn’t have time to think about during the day — like family and God." Bieber says he doesn’t always have time to think about these important things because "you just get caught up (in everything else) during the day."

Bieber’s multiplatinum-selling album, "My World 2.0," is up for a Grammy for best pop vocal album; he’s also up for best new artist.

The February issue of Vanity Fair hits newsstands in New York and Los Angeles on Jan. 6 and nationally on Jan. 11.