Here are a couple of sentences I found surprising:

The studies examined were conducted between 1987 and 1999 and covered Prozac, Paxil, Zoloft, Celexa, Serzone, and Effexor. They found, on average, that placebos were 80 percent as effective as the drugs.

Update: I wanted to pull up a link from the comments to a blog post the Public Library of Science that sheds more light on this issue.