Demi Lovato is celebrating her sixth year of sobriety, telling others "it is possible".
The actress and musician revealed that, at 21 years old, she was addicted to alcohol and drugs, but she had worked hard to overcome her struggle.
"Today is a very special day for me... I'm officially celebrating six years of sobriety!!" she wrote on Twitter on Thursday (local time).
"A huge part of my recovery was learning to love myself and to give back to others."
She thanked friends, family and the CASTS rehabilitation centre for their support.
"So grateful for another year of joy, health and happiness," she said. "It IS possible."
Lovato released the documentary Simply Complicated last year, detailing her dark past.
It reveals that she was bullied intensely at high school and developed an eating disorder that she still struggles with today.
She first used cocaine as a 17-year-old Disney Channel star, and became addicted to Adderall and cocaine while still a teenager.
At 18, she was diagnosed with bipolar disorder.
She is passionate about MMA fighting and jujitsu as a way to stay fit and healthy.