"Antidepressants Under Scrutiny Over Efficacy" --WSJ January 2008

Antidepressants Under Scrutiny over Efficacy -- Wall Street Journal, Jan 2008

More evidence that (surprise, surprise) drug manufacturers attempt to present their products in the best possible light. And why not... if they happen to get called on fraud they just settle for a couple hundred million... peanuts.

A total of 74 studies involving a dozen antidepressants and 12,564 patients were registered with the FDA from 1987 through 2004. The FDA considered 38 of the studies to be positive. All but one of those studies was published, the researchers said.

The other 36 were found to have negative or questionable results by the FDA. Most of those studies -- 22 out of 36 -- weren't published, the researchers found. Of the 14 that were published, the researchers said at least 11 of those studies mischaracterized the results and presented a negative study as positive.

...

Dr. Turner, who once worked at the FDA reviewing data on psychotropic drugs, said the idea for the study was triggered in part by colleagues who questioned the need for further clinical drug trials looking at the effectiveness of antidepressants.

"There is a view that these drugs are effective all the time," he said. "I would say they only work 40% to 50% of the time," based on his reviews of the research at the FDA, "and they would say, 'What are you talking about? I have never seen a negative study.'" Dr. Turner, said he knew from his time with the agency that there were negative studies that hadn't been published.

...

In this week's study, the researchers found that failing to publish negative findings inflated the reported effectiveness of all 12 of the antidepressants studied, which were approved between 1987 and 2004. The researchers used a measurement called effect size. The larger the effect size, the greater the impact of a treatment.

Effexor's estimated effect size was 27% (XR) and 28% in the study. Zoloft 64%. Paxil 40%. Prozac 14%. These are the increased apparent effectiveness of the drug treatments because of the omission of negative reports. You could read this as X% less effective when the positive bias is removed.