(Cover) - EN Showbiz - Amanda Seyfried is terrified of turning 25.

The young actress will celebrate the landmark birthday in December. While she is extremely happy with everything she has achieved so far, Amanda admits she is scared of getting older.

She is convinced everything can only get harder from now on because her life has been charmed so far, and the thought keeps her awake at night.

The best thing [about turning 25] is, Im happy, Amanda told the October issue of the US edition of Elle magazine. The worst is that Im scared; the scariest thing is that I know it cant be easy - the years to come.

Amanda appeared in the magazine as one of Elles 25 women under 25. Gabourey Sidibe, Megan Fox and Lauren Conrad also shot their own covers for the issue, and spoke about how they feel about getting older.

Gabourey, who shot to fame playing a troubled teenager in movie Precious, revealed she threw a 21st birthday party when she turned 25 earlier this year because she was worried people wouldnt think she was believable in the movie if they knew how old she actually was.

Part of me thought it would be weird if people knew I was a grown-up playing a teenager in Precious. So I had a 21st birthday party, Gabourey laughed. We had drinks and went to a strip club called Shotgun Willies.

Reality star Lauren Conrad loves being in her 20s because she feels like she can be completely selfish. She is using her youth to focus on her career and plans to figure out everything else later.

Its your time to be selfish; you still have freedom, Lauren said. I was never that girl who just wanted babies. I wanted a career before all of that. (C) Cover Media