The 32-year-old Heroes and Nashville actress said she also suffered depression after becoming a mother.

She has had trauma therapy and in-patient treatment as recently as the past year, she told US publication People.

"I was on top of the world and I ruined it... I'd think I hit rock bottom, but then there's that trap door that opens," she said.

Panettiere found fame as a teenager and said she was only 15 when a member of her staff gave her "happy pills" before red carpet events, eventually opening the door to addiction.

"My saving grace is that I couldn't be messy while on set and working," she told the publication.

"But things kept getting out of control [off set]. And as I got older, the drugs and alcohol became something I almost couldn't live without."

She also suffered depression after the birth of the daughter she shares with her ex, former Ukrainian boxer Wladimir Klitschko.

It was so bad she had to send Kaya, now seven, to live with her father in Ukraine.

"It was the hardest thing I ever had to do," she said. "But I wanted to be a good mom to her - and sometimes that means letting them go."

She added: "I never had the feeling that I wanted to harm my child, but I didn't want to spend any time with her.

"There was just this grey colour in my life."

Back in February, Panettiere revealed on Instagram that her daughter was "safe" and no longer in Ukraine following Russia's invasion of the country.

The American star, who has also appeared in several Scream films, told People that her addictions to drugs and alcohol were an attempt to "feel happy for a moment".

She said she would wake up with "the shakes" - with alcohol the only way to subdue it.

At just 20, she was hospitalised.

"Doctors told me my liver was going to give out," she said.

An eight-month stay in rehab helped her battle her addiction and now the actress is doing much better, with a role in the next Scream movie and also founding a charity earlier this year to raise funds for Ukraine.

She told People: "I don't regret even the ugliest things that have happened to me. I feel incredibly accomplished. And I feel like I have a second chance."

Anyone feeling emotionally distressed or suicidal can call Samaritans for help on 116 123 or email This email address is being protected from spambots. You need JavaScript enabled to view it. in the UK. In the US, call the Samaritans branch in your area or 1 (800) 273-TALK.