Pop Star Justin Bieber admits teen drug use

Justin Bieber has admitted he started doing heavy drugs when he was a teen due to the pressures of being a child star.

In a lengthy message on Instagram, the Canadian singer says that fame went to his head and that he made a very bad decision by the time he was 20.

Bieber, now 25, was discovered on YouTube by talent manager Scooter Braun when he was just 13.

“Stardom puts an insane pressure and responsibility on a child's brain at a time when their emotions and frontal lobes aren't developed yet," he said.

The star, now married to Hailey Baldwin, told fans there were days in his past when he felt overwhelmed by life and suffered depression.

Bieber also wrote about his fall from grace, going from being one of the most loved and adored people in the world to the most ridiculed, judged and hated.

He has often made headlines for his controversial behavior rather than his music, and in 2014, a petition demanding he be deported from the U.S. attracted more than 100,000 signatures.