In a move that surprised  many rock fans, Three  Days Grace front-man Adam Gontier abrubtly left the band.  According  to the band, Adam submitted a letter of resignation on December 21.   Now, Adam has addressed rumors for exactly why he left the band.  He  says he has battled drug addiction in the past but claims that he is  sober.

Read  the full letter below:

"To all of my fans,  my friends, my family, these are my words coming from my heart, separate from my  role as “lead singer of Three Days Grace”.

I  want you all to know how very thankful I am for your consistent love, your  respect, and you’re undying support. It is important for me to address any  concerns regarding my health being connected to  drugs or addiction. The truth is, when I was struggling during that dark time in  my life, I hit rock bottom, and I had the kindest of people reach out from all  over the world, and reach their hands out to help pick me up. I am so blessed to  be walking in the light now. I am reminded of your loyalty, always. The truth  is, and I’m very proud to say this..., I am sober. That chapter in my life is  over.

There have been many defining moments in my life. My time as  part of Three Days Grace is most definitely one of the miraculous ones. I have  had so many tender hearted people share with me their stories. How I’ve touched,  or changed their lives. My truth is that all of the love I have received has  forever changed my life. Each letter I’ve read, every picture I’ve been sent,  all of the voices I’ve heard sing along with me, I will forever remember, and  never forget...

After twenty years of being part of an ever evolving  band, I have been inspired by life, to move on and to continue to evolve on my  own terms. I could not be more grateful for all the souls who have travelled  along with me. A journey I look back on with integrity, and a future I look  forward to with such hope. I have always admired brave hearts. Life is always  changing. I will continue to follow my heart, and what I love to do. I’m not  sure what the next horizon will look like, but I do have all the faith in the  world that whatever it is, It’s meant to be, and I have faith that blessings  will continue to shine over all of us. I once heard a “brave heart” say:

“When nothing is sure, everything is possible.”

It’s because  of my life’s journey, because of all of you, that I  believe.

Sincerely, with  love,

Adam"