You can control your symptoms IMO but it is hard to lick depression for good. Most people have more than one episode of it in their lives and some of us unfortunate ones deal with it on an almost constant basis.

Like Leed said, meds and therapy do help. Therapy will give you tools to deal with the depressive mindset and hopefully give you ideas to keep stress at bay. Meds help a bit but are not a cure all. Eating a healthy diet is important as is finding healthy ways to deal with stress. Sometimes even with all of these other things in place, depression can still be an issue.