Justin Bieber has admitted he started doing “pretty heavy drugs” when he was a teenager 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 every 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 (decision making) 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 with depression, sometimes getting to the point “where you don’t want to live any more”.
He said: “I started doing pretty heavy drugs at 19 and abused all of my relationships. I became resentful, disrespectful to women, and angry.
“I became distant to everyone who loved me, and I was hiding behind a shell of a person that I had become. I felt like I could never turn it around.
“It’s taken me years to bounce back from all these terrible decisions, fix broken relationships, and change relationship habits. Luckily god blessed me with extraordinary people who love me for me.”
The Sorry singer says “money, clothes, cars, accolades, achievements and awards” made no difference to his happiness, and finding fame at such a young age meant he struggled to deal with the real world.
“Everyone did everything for me, so I never even learned the fundamentals of responsibility,” he said. “By this point, I was 18 with no skills in the real world, with millions of dollars and access to whatever I wanted.”
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 behaviour rather than his music, and in 2014, a petition demanding he be deported from the US attracted more than 100,000 signatures.
The says it took him years to bounce back and fix broken relationships but that he is now “navigating the best season of my life”.
Bieber put his current positive mindset down to his marriage, which he describes as a “crazy new responsibility”.
A devout Christian, he also spoke religion, telling anyone struggling with life: “Jesus loves you.”
His message has been liked more than 2.5 million times.
Bieber, who recently collaborated with Ed Sheeran, hinted over the summer that he would be releasing new music later this year.