One-X peaked at number two on the Canadian album chart and at number five on the Billboard 200, selling 78,000 copies in the US in its first week of release. Apar pointed out that Three Days Grace is 'hardly innovative' in their approach to writing music and that 'further distinctive qualities' would help the band separate itself 'from their alt-metal peers'. The album did receive some negative criticism. The Toronto Star complimented the album with a review title of 'One CD worth buying.' and focused on its lyrics, saying, 'The lyrics really speak out to you, especially if you're going through a tough time in your life.' Allmusic reviewer Corey Apar praised the music, saying it 'remains catchy despite its lyrical darkness'. One-X was met with generally mixed reviews. The album, titled One-X, was then released on June 13, 2006, and was guitarist Barry Stock's recorded debut. In a 2006 interview, Gontier said that the album's material was more personal to him than the band's previous work because the material had come out of his experiences with despondence, drug abuse, and rehab that had constituted the past two years of his life. 'Over and Over','Gone Forever' and two more hit singles, ' Pain ' and ' Never too Late '.

Three days grace first album lyrics