Interesting stuff.
I maintain that stress (physical and mental) and stasis (lifestyle, physical and mental) are the two biggest causes/contributers to depression. Once depression arrives either self-absorption or disinterest (or combination of both) can take over, creating a cycle of misery and confusion.
I would look at fully identifying and addressing both stress and stasis before resorting to drugs. I was 14 years ago prescribed Citalopram (reactive depression) but it made me feel weird, disturbed sleep etc. However, a move, a life-change, a relationship change, a career change, and more and different physical exercise all combined to lift the fog and lend a healthy dose of hindsight which so far has prevented recurrence. Not even fingers crossed.