Lovato has been open about her struggles with the illness for many years, and celebrated her six-year sobriety from drugs and alcohol in March.
However in a new single, she appears to admit to falling off the wagon. Its powerful lyrics see her saying, “To the ones who never left me, we’ve been down this road before – I’m so sorry, I’m not sober anymore.”
Fans have immediately taken to Twitter to flood Lovato with messages of support, and #Sober has been trending worldwide.
The most important thing the song does is remind the 25-year-old’s fanbase – predominalty young, but ultimately of all ages and backgrounds – that addiction is an ongoing battle that doesn’t simply end when one manages to go sober.
In a tweet that is rapidly being spread, one listener said: “I think what people don’t understand about addiction is that it is always there and it’s so easy to slip back into old habits.
“Demi no longer being sober does not take away the 6 years that she was, she’s so strong. She will get through this. #SOBER.”
Another wrote: “this is such an important and vulnerable moment that Demi has shared with us, and what we have to do as fans – is to continue supporting her.
“We know what she has gone through and how strong of a woman she is. #Sober.”
Lovato spoke openly about her addiction battle in her documentary Simply Complicated, released online last year.
“I loved it,” she admitted of her past drug use. “I felt out of control the first time I did it.
“My dad was an addict and an alcoholic. Guess I always searched for what he found in drugs and alcohol because it fulfilled him and he chose that over a family.”
A public fallout with her dancer in 2011 led to a stint in rehab, but she relapsed fairly quickly thereafter.
“I was using while I had a sober companion and I went through like 20 sober companions,” she had said.
“I was either craving drugs or on drugs. I was not easy to work with. It’s embarrassing to look back at the person that I was.”
It was a hungover performance of Give Your Heart A Break on American Idol in 2012 that finally prompted her to give up drinking.
Lovato will continue her international tour with a concert in London on Monday. She is also expected to score her first ever UK number one tomorrow, thanks to her collaboration with the band Clean Bandit.
Sober by Demi Lovato is out now.