Davidson, 23, wrote on Instagram that he is happy and sober for the first time in eight years, and thanked his girlfriend, Cazzie David, and others for their support.
Just wanted to let you guys know I'm okay. I know I've kinda been missing, on social media and on the show. I quit drugs and am happy and sober for the first time in 8 years. It wasn't easy, but I got a great girl, great friends and I consider myself a lucky man. I'll always be here for you guys, I promise. Remember to never give up hope because sometimes that's all we got. We are a family and I appreciate all your love and support. It's nice to be back in action
He also posted photos with David, the daughter of comic actor and writerLarry David.
Davidson joined Saturday Night Live in 2014.
In a sketch that aired Jan. 26, Davidson played a student in a support group for college kids whove broken the schools alcohol rules.