I used to. I had a bad habit of overthinking and I used my vices like a crutch. But I was also scared of becoming happy. I was scared that I'd lose my edge. I was scared that I'd become like the "happy" Christians around me, who I saw as blissfully ignorant, unambitious and sheep minded. And even if I were to become happy, I didn't trust it not to pull the rug from under my feet given the chance. Worst of all I didn't think I had the "right" to be happy, almost like some masochistic priest who lived his life in abstinence and guilt, cordoned off from the rest of the world. Contempt, guilt, addiction, and self pity are the pillars of depression. Before you can become happy you have to be willing to let go of all of those things. Next you'll need empathy, a good work ethic, tolerance, and love for yourself and your fellow man. I'm no expert on this stuff, but that's my experience.