Stuart Jeffries speaks Adam Phillips at the Guardian (this is Phillips talking in the quotation below--and if you haven't read any of his books, you should, they have an appealingly restless and inquisitive quality that pleases me greatly):
The reason that there are so many depressed people is that life is so depressing for many people. It's not a mystery. There is a presumption that there is a weakness in the people who are depressed or a weakness on the part of scientific research and one of these two groups has got to pull its socks up. Scientists have got to get better and find us a drug and the depressed have got to stop malingering. The ethos is: 'Actually life is wonderful, great - get out there!' That's totally unrealistic and it's bound to fail.
(Thanks to Bookslut for the link.)