What new data did dr. kirsch review that raised questions about the efficacy of antidepressant drugs?

In the summer of 2011 there was an article published in Newsweek magazine that featured Dr. Kirsch who stated that he thought antidepressant drugs were in people's heads and that they were "no more effective than placebos" In Dr. Kirsch's research the drugs mildly outperformed the placebos when it came to treating mild to moderate depression but Dr. Kirsh felt the overall benefits were small. Dr. Kirsch did extensive research reviewing placebo pills on depression versus anti depressants. He even wrote a book on the topic called The Emperor’s New Drugs: Exploding the Antidepressant Myth.