Lady Gaga From her autobiography in 2010 , we find out that the famous singer has several battles with addiction in the past. Even if cocaine was the primary drug, she did dabble in other substances too. Eva Mendes Her open attitude about addiction has been an impressive example for other celebrities to step in and publicly recognize the need for help. Zac Effron He went to rehab not once, but twice. He has also talked openly about it, which only helps other people dealing with addiction. Daniel Radcliffe The star from Harry Potter has been filming drunk several times. Once he checked into rehab, he managed to stay away from alcohol for good . Selena Gomez Selena Gomez shocked her fans when she canceled an entire summer tour, checking into a high-end rehab institution. Having panic attacks drained the actress, and she finally enrolled in rehab. Terry Crews The NFL-star started to talk about his addiction only to prove that he’s stronger than the addiction. The addiction to porn almost put an end to his marriage. The star got into rehab and decided to be vocal about it in order to take the power away from his addiction. Mariah Carey She talked about the emotional breakdown that required psychiatric treatment. Ever since the 2001 moment, it seems that the singer has been taking up drinking and anti-depressants. Oprah Winfrey The queen admitted her cocaine addiction during the beginning of her career in 1995. Oprah was very spontaneous about her struggle with cocaine addiction.