The singer and songwriter thanked her family, friends and CAST centers, a mental health and wellness program organization she created to help people struggling with addiction receive treatment, for being integral to her journey and recovery.

Today is a very special day for me... I'm officially celebrating 6 years of sobriety!! I'm so thankful to my family, friends and @castcenters for being a part of this journey. A huge part of my recovery was learning to love myself and to give back to others.

Lovato proclaimed "it IS possible" in her celebration tweet and launched a contest with CAST centers to give her fans and others that have recovered from addiction a chance to tell their stories. "A huge part of my recovery was learning to love myself and give back to others," Lovato said in her tweet.

"We're launching a contest to give you guys the opportunity to use YOUR voice & share your stories."

The contest will give one person the chance to be a special guest speaker during the final US concert on Lovato's #tellmeyoulovemetour in Tampa, Florida. The winner will be selected on the CAST tour Instagram on March 27th.