In his new book Friends, Lovers, and the Big Terrible Thing, Friends actor, Matthew Perry, opened up about his struggles with addiction and his journey to sobriety.

Like Perry, 21 million Americans struggle with addiction. But for such a prevalent disease, addiction isn't so widely discussed.

Here are 19 celebrities who've publicly shared their own sobriety journeys to shine a light on and help those struggling with addiction:
1. Matthew Perry

2. Jamie Lee Curtis

3. Tom Felton

4. Robert Downey Jr.

5. Elton John

Here's how he celebrated his 30th Sobriety Birthday!!!
If I hadn’t finally taken the big step of asking for help 30 years ago, I’d be dead. Thank-you from the bottom of my heart to all the people who have inspired and supported me along the way. 🙏🏻🙏🏻❤️❤️😇😇
6. Drew Barrymore

7. Kit Harington

8. Daniel Radcliffe

9. Samuel L. Jackson

10. Carrie Fisher

11. Zac Efron

12. Naomi Campbell

13. Jane Lynch

14. Demi Lovato

15. Florence Welch

16. Dave Coulier

Here's his Instagram post:
17. Hayden Panettiere

18. Jessica Simpson

19. And lastly: Jason Biggs

And here's his AA coin celebrating one year sober!
If you or someone you love is struggling with an addiction, here are some resources that might be of help:
Find an Alcoholics Anonymous meeting group near you here.
Talk to a representative from the Substance Abuse and Mental Health Services Administration (SAMHSA) on their free, confidential, 24/7 national helpline by calling 1-800-662-HELP.
Or if you or someone you love is having suicidal thoughts, call or visit the Suicide Prevention Lifeline at 1-800-273-8255.