"All of this has led to question mental illness. Not because I don't believe in biological causes for mental illness, but because I believe that there could be social factors that play into it as well. With depression in particular I wonder: Has depression actually been on the rise in the world, or are we just now beginning to understand that these seemingly unrelated symptoms are indicative of an chronic illness, and thus able to diagnose and treat them? Are normal life stressors leading people to believe that they are mentally ill and in need of drugs instead of learning coping mechanisms and life skills? Does the rise in the treatment of depression have more to do with the increase in advertising than the increase in actual cases?"
The best thing I've read that relates to your question is Thomas Szasz's "The Myth of Mental Illness."
I think alienation and stress (the two pillars of post-modern life) play a large part in depression and anxiety. In addition, the intensification of work/responsiblity, gives us much less time in which to recuperate from even minor trials and tribulations. Consider for example, the experience of motherhood in the United States, which requires most mothers to return to work within weeks, sometimes days of delivery (the effect on mother and child). Consider the general anxiety about health-care, or about job-loss, or about crime.
Unrelenting, cumulative stress and minor trauma lowers our energy and therefore our ability to defend against unpleasant emotions -- like depression and anxiety -- or, for that matter to defend our bodies, which fall prey to chronic physical disease (another cause of depression). And so it goes. And no time. How many people can afford therapy -- even for traumatic events? So, pop a pill.
Consider also the history of the twentieth century - ravaged by world wars in the "civilized" nations, and the butchery of proxy regional wars in the third world.
There are periods that seem more characterized by depression than others, for example the melancholia of the seventeenth century in north-west Europe -- after the dissolution of feudalism. But ours I think is more an age of anxiety, (depression being in large part a defense against anxiety -- and so, no wonder that one drug applies to them both.) And it manifests itself in the "illnesses" that top the charts for the pharmaceutical industry: anti-depressants, anti-anxiety drugs, and heart medication.
Joanna