newyorker:

Once upon a time, depression was generally seen as a purely psychological disturbance; these days, people are likely to think of it as a tidy biological syndrome. In fact, it’s hard to make sense of the distinction. Most depressive disorders are now thought to involve a mixture of reactive (so-called neurotic) factors and internal (“endogenous”) factors; depression is seldom a simple genetic disease or a simple response to external troubles. Resolving the biological and the psychological understanding of depression is as difficult as reconciling predestination and free will.

Read the full story, “Anatomy of Melancholy,” here.