Demetria Devonne Lovato ( lə-VAH-toh; born August 20, 1992) is an American singer, songwriter, actress, and television personality. She began her career in 2002 appearing on the children's television series Barney & Friends, before rising to prominence for portraying Mitchie Torres in the Disney Channel musical television film Camp Rock (2008) and its sequel Camp Rock 2: The Final Jam (2010). Lovato has released six studio albums: Don't Forget (2008), Here We Go Again (2009), Unbroken (2011), Demi (2013), Confident (2015), and Tell Me You Love Me (2017); all of which debuted in the top five of the Billboard 200. She has earned seven top-20 tracks on the Billboard Hot 100 with "This Is Me", "Here We Go Again", "Skyscraper", "Give Your Heart a Break", "Heart Attack", "Cool for the Summer", and "Sorry Not Sorry". In total, she has sold over two million albums and 20 million singles in the United States. On television, Lovato has starred as the titular character on Sonny with a Chance (2009–2011), served as a judge and mentor on The X Factor USA in its second and third seasons, and appeared as a recurring character on Glee. Her struggles with several personal issues have received significant media attention in the 2010s; in response to which she published the book Staying Strong: 365 Days a Year (2013) and released a YouTube documentary about her life and career, titled Demi Lovato: Simply Complicated (2017). Lovato is a pop, pop rock, and R&B artist. She has earned numerous awards and nominations, including an MTV Video Music Award, 14 Teen Choice Awards, five People's Choice Awards, two Latin American Music Awards, one American Music Award nomination, four Billboard Music Award nominations, three Brit Award nominations, and two Grammy Awards nominations. She also holds one Guinness World Record and was included on the annual Time 100 list of the most influential people in the world in 2017. Outside the entertainment industry, Lovato is an activist for several social causes.