A source tells ET that the 25-year-old singer is "doing much better" and is expected to leave the Cedars-Sinai Medical Center in Los Angeles sometime this week.
"Demi has been in the hospital for over a week because she needed to be monitored by a medical professional," the source says. "During her time in the hospital, she became physically sick, and the doctors wanted to make sure they kept a close eye on her until they were certain she was fine to be released."
"Her and her team need to decide what is the best decision for Demi once she leaves the hospital," the source adds, referencing reports that her family wants to get her back into rehab immediately. "Demi has told the people close to her that she is serious about her sobriety, and plans to do whatever it takes to maintain a healthy lifestyle moving forward."
An additional source told ET earlier this week that Lovato was "experiencing nausea and fever" following her apparent overdose last Tuesday, when she was rushed to the hospital.
Lovato's closest friends and family have been by her side, including her ex-boyfriend, Wilmer Valderrama, whom she split from in 2016 after six years together. "Demi is getting better day-by-day with the help of her family, friends and Wilmer," a source told ET at the time. "He visits Demi every day he can, and has spent hours with her and her family."
"Wilmer and Demi have always shared a strong bond, and Wilmer knows Demi better than anyone," the source continued. "He's seen her highs and lows, and has always been there for her, and he knows she needs him now more than ever."