Justin Bieber is opening up about the “bad boy” behaviour that once characterized him in a new interview with GQ.

“There was a sense of still yearning for more,” he recalled. “It was like I had all this success and it was still like: ‘I’m still sad, and I’m still in pain. And I still have these unresolved issues.’ And I thought all the success was going to make everything good.”

As a result, he began to self-medicate with drugs.

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“And so for me, the drugs were a numbing agent to just continue to get through,” Bieber admitted.

In fact, he told the magazine, his drug use grew so out of control that members of his security team would routinely check his pulse when he was sleeping to ensure he hadn’t overdosed.

“I just lost control of my vision for my career,” he explained.

“There’s all these opinions. And in this industry, you’ve got people that unfortunately prey on people’s insecurities and use that to their benefit,” Bieber added.

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“And so when that happens, obviously that makes you angry,” he said. “And then you’re this young angry person who had these big dreams, and then the world just jades you and makes you into this person that you don’t want to be. And then you wake up one day and your relationships are f**ked up and you’re unhappy and you have all this success in the world, but you’re just like: Well, what is this worth if I’m still feeling empty inside?”

The entire interview appears in the May issue of GQ.