The 43-year-old actress voluntarily checked herself in for treatment this past week after lapsing back into heavy drinking.
The alcohol bout followed a bitter breakup with her husband Robert Gilliam, according to gossip site TMZ.
“She had been fighting demons for a while and finally lost her battle,” her agent told the site.
Kelly filed for divorce from Gilliam in July, but their stormy relationship continued. He allegedly beat her up to force her to pay him some of the money she received as residuals from the hit comedy show, which is still in reruns.
He was convicted of domestic battery and sentenced to three years probation and 35 days in jail for the beating. But that wasn’t her only brush with trouble.
Kelly was arrested in North Carolina in 2010 for drunk driving and pleaded guilty to the charge. She was fined and sentenced to 12 months unsupervised probation.
In March last year, she and then-boyfriend John Michas got in a bitter row and he pressed charges against her for corporal injury upon a spouse, a felony. She later claimed she was assaulted
In May a year ago, the Los Angeles County District Attorney declined to charged her.
Kelly told ABC News around the time of the Michas incident that losing a baby caused her to spiral downward. “As a result of that I lost it. I lost everything and I was abusing alcohol,” she said.
At the time, she said she was sober and planning a comeback, but she never landed a substantive role that equaled her run from 1998 to 2003 on “That ’70s Show.”
Kelly played Laurie the promiscuous and slightly evil older sister to Eric Foreman, the show’s main character played by Toper Grace. The hit show launched his careers as well as those of Kutcher and Kunis, who are now dating.
Check out her 2012 interview with ABC News below and follow TheImproper on Twitter for the latest celebrity news.