Despite recent debate about how well antidepressants really work in people with only mild or moderate depression, a new analysis of drug studies suggests they may have some benefit across the board.
Researchers found that more patients taking Prozac or Effexor had a substantial improvement in their symptoms than those taking a drug-free placebo pill, regardless of how severe those symptoms were to begin with.
"The idea that unless you're very, very ill, you're not going to benefit from treatment does not appear to stand up" when looking closely, said the study's lead author, Robert Gibbons, from the University of Chicago.
Still, not everyone in the studies improved -- on average, about five people had to be treated with one of the drugs for one person to feel better, and the benefits seemed to be diminished among some of the oldest patients.
What's more, one researcher not involved in the study said its findings still don't mean the drugs are any better than non-drug methods of treating depression, such as and being more physically active.
For their analysis, Gibbons and his colleagues looked at outcomes for each individual patient in published and unpublished trials testing the effects of six weeks of treatment with antidepressants versus placebo pills. Most of those trials were funded and run by the pharmaceutical companies that manufacture Prozac and Effexor -- Eli Lilly and Wyeth, respectively.
They included 12 studies of Prozac in adults and four each in elderly patients and youth, as well as 21 trials of immediate- or extended-release Effexor in adults. About 9,000 participants were included.