Demi Lovato has blamed punching a dancer and overdosing on heroin on the "negative impact" of fame.

The 32-year-old singer was arrested in 2010 after punching dancer Alex Welch and Demi had a near-fatal overdose in 2018 which led to three strokes and a heart attack but the star blames fame for the incidents.

Demi told Grazia US: "I didn’t know that it would have such a negative impact on my mental health. And unfortunately, sometimes that looks explosive, like an incident where you punch your backup dancer on an airplane or you overdose from heroin.”

Demi has co-directed the new documentary 'Child Star' with Nicola Marsh and explained that working on the film presented the opportunity to try to make amends with those the star had hurt in the past.

Demi said: "Talking to people who knew me at a different time in my life was challenging because I wanted to apologise for my behaviour. I wasn’t the nicest person to work with at times because I was struggling so much internally, and I was under a lot of pressure.

"They were so lovely, so incredible, and so receptive, and I was so grateful for that."

Speaking previously about 'Child Star', Demi told PEOPLE: "This was just a story that I had been wanting to tell for quite some time. I've always thought about exploring the history of child stars, and also looking at different points of views and the perspective of what it's like to be a child star in today's day and age.

"I've been very, very honest in the past and demonstrated that vulnerability throughout my life.

"I've shared a lot with people, and [I know] that my experiences don't define me."

'Child Star' features interviews with Drew Barrymore, JoJo Siwa, Kenan Thompson, Raven-Symoné, Christina Ricci and Alyson Stoner.