Completely the opposite, actually. One hallmark of clinical depression is that you suffer from severe emotional upset despite circumstances that should not cause it, that's the whole point of being depressed. You should feel better because there's nothing truly wrong but you can't and that makes you feel even worse, because you keep thinking, "What the fuck is wrong with me? I feel like killing myself and my biggest worry is which table I sit at for lunch break. Why the fuck can't I just chill out?"
But again, whether her depression was caused by some unknown biological anomaly or because of events in her life; her depression was neither more or less serious.