Demi Lovato awake after suspected overdose

US pop star Demi Lovato is reportedly stable after suffering a suspected drug overdose in Hollywood

Pop star Demi Lovato, who has been open about her history of drug and alcohol abuse, is awake in hospital after suffering a suspected overdose, according to media reports.

Lovato, 25, a Grammy-nominated recording artist, was "OK and stable", People magazine reported, quoting an unidentified source.

"Demi is awake and with her family who want to express thanks to everyone for the love, prayers, and support," Lovato's representative told entertainment magazine Variety in a statement.

Representatives for Lovato did not respond to a request for comment.

Lovato's concert in Atlantic City, set to take place on Thursday at Atlantic City Beach, has been cancelled, Variety reports.

Her Live Nation tour has been running since February 2017.

Entertainment news website TMZ, quoting law enforcement sources, reports that Lovato was found unconscious at her home and was treated with Narcan, an emergency antidote for suspected opioid and drug overdoses.

Lovato released a song last month called "Sober" in which she sang: "Momma, I'm so sorry, I'm not sober anymore, And daddy, please forgive me for the drinks spilled on the floor, To the ones who never left me, We've been down this road before, I'm so sorry, I'm not sober anymore."

The singer rose to fame on Disney Channel shows "Camp Rock" and "Sonny with a Chance" 10 years ago and forged a pop career with hits like "Skyscraper" and "Sorry Not Sorry."

In a 2017 YouTube documentary, "Simply Complicated," Lovato spoke about years of substance abuse, eating disorders, and drinking, saying she first started using cocaine when she was 17.

At the age of 18, she entered rehab, where she was diagnosed with bipolar disorder.

Lovato, who has some 69 million followers on Instagram, was in the midst of a US tour and was due to perform in New Jersey on Thursday.

On Twitter fans and celebrities have been expressing concern and support.

Country singer Brad Paisley tweeted: "Addiction is a terrible disease. There is no one more honest or brave than this woman.