genetics might contribute to this sometimes. Hemingway and several of his immediate family members killed themselves.
my english teacher said this was a "tragedy which would not happen today", and went on to talk about how he should have been on antidepressants.
i always wonder what makes some people so quick to recommend antidepressants, while some revile them so much. especially since, as far as i know, many of the people i hear opinions from haven't ever taken them (myself included).
my own parents have implied "depression runs in our family" and asked me to use antidepressants, which is about the extend of my "experience" with this subject. however, i can't help my suspicion. i think the "genetic tendency to depression" really just means "the intelligent person's tendency to depression". in my view, most people live in circumstances I find depressing -- only the privileged few don't. however, lots of people who live in circumstances that would depress me seem a lot less concerned than i would be. i'm not trying to sound arrogant, but these people tend to come off as simpletons who are satisfied with little. on the other hand, a lot of the more "complex" people i know (whether directly, as friends, or famed thinkers from books, etc.) have a lot of trouble with things that simply don't matter to most people.
maybe "intelligence" is the wrong word, or at least overly general. to be more specific, i think introspective people who develop strong concepts (in general) and a strong self-image (in particular) can be prone to "depression". you begin forming your self-image, or identity, as a child, when you don't know much about the world. as an adult, this image eventually comes into question as you begin to learn that you were wrong about yourself. reshaping your identity as an adult can be very difficult: an athlete who can no longer compete at the highest levels, an artist whose works go unrecognized, an aspiring lawyer who can't get into law school, a "surgeon" with an unsteady hand, etc. these people often build their life around what they wish they were, rather than what they are.
less introspective people, or people who had a more accurate view of themselves as a child, don't run into this problem, and can just "go with the flow". in other words, if you never thought much of yourself (the "simpletons" i referred to earlier) or if you really do achieve your goals (e.g. the "privileged few" i mentioned earlier), you'll probably appear "happy" to others. if you're a failed "X" who, to survive, trudges on as a half-hearted "Y", you'll appear depressed. to bring this back to "genetics", the latter requires you strongly to perceive yourself as an "X". to develop a strong self-concept requires more intelligence, i think, a trait which is largely "genetic".
after all, are many animals depressed? from all appearances, "no", and they don't seem to be particularly "self-aware". similarly, "depression" seems to be most diagnosed amongst more affluent populations -- is this an artifact of "other interests" (e.g. medical industry), or is there really something to the image of the "simple, satisfied peasant"?
to expand on the last question a little, is it any wonder that so many people in the US, in particular, are diagnosed with "depression" when they flip burgers by day and stuff their brains with idealized images of the "rich and famous" on their computers by night? the fact is, few have the ability to rise to the top, but nearly everyone has the ability to measure themselves against the successes of others, which are made ubiquitous through the internet, etc.
i'm sure some of you will find this post dripping with ignorance and first-world pussification, and i won't necessarily disagree... again, these thoughts are only based on some recent experiences. i'm sure there are many ways to link genes and depression, this is just the explanation that seems most important to me, and as a consequence of my reasoning above, i'm a little wary of those who further conclude, "well if your depression is caused by your genes, your genes are the problem. antidepressants are the solution."