The 'X Factor' judge entered a treatment facility in October 2010 to seek help for an eating disorder, self harm and bipolar disorder and says when she left in January 2011, part of her plan to turn her life around was to make sure she only spent time with people who truly cared about her.
She said: "I'm consistently busy, but I make sure I spend a lot of time with my friends and family. I did kind of a friend cleanse right after rehab, where I weeded out people who didn't have my best interests at heart.
"Now I have friends who love me for who I am and don't care about what I'm doing. Most of them aren't in the industry. Some of them don't even know my songs!"
Despite her busy schedule working on 'The X Factor' and recording new music, Demi, 20, knows her health has to come first so always makes time for therapy and establishing a proper routine.
She added in an interview with Teen Vogue magazine: "I sleep, eat right, exercise, and meditate. And even when I'm filming or touring, I keep up my daily routine. I know that I can't miss my therapy appointments or things will get a little rocky, so I always put my recovery first."
And the 'Skyscraper' hitmaker knows she isn't ready for a relationship yet as she needs to spend time keeping herself happy and worrying about her own needs.
She said: "I'm in a place right now where I really need to focus on myself. Obviously, I'm still going to like people - or love them - but I need to not be in a relationship for a while because I need to be OK with being alone, first. I'm really happy right now. I never thought it was possible to be happy because of how depressed I was my entire life. But I feel so incredible. It's like I'm living in a dream."