Pfizer Inc's Zoloft and Forest Laboratories Inc's Lexapro are the most effective and well-tolerated antidepressants among a group of 12 new drugs, according to an analysis published on Thursday.
The findings from a review of 117 studies provide a "gold standard" of reliable information for patients to review before starting treatment, said Sagar Parikh, psychiatrist at the University of Toronto, who was not involved in the study.
"Such findings have enormous implications," he wrote in a commentary in the journal Lancet, which published the review.
"Now a clinician can identify the four best treatments, identify individual side-effect profiles, explore costs and patients' preferences and collaborate in identifying the best treatment."
Over the past decades several new drugs have hit the market to treat depression, a leading cause of suicide that affects an estimated 121 million people worldwide.
But many are similar in structure and the way in which they work, so it is unclear which ones work best, Andrea Cipriani and colleagues wrote in the journal Lancet.
"Moreover, some of these new drugs are so-called me-too drugs — chemically similar to existing drugs with expiring patents rather than giving genuine advances in treatment," they wrote.
The team reviewed 117 studies from 1991 to 2007 that compared the response and drop-out rates of the drugs among more than 25,000 men and women with major depression.
Overall, Zoloft, or sertraline, and Lexapro, or escitalopram, were best when it came to both reducing symptoms after eight weeks and drop-out rates during the studies.
Far more people remained on the two drugs compared to Eli Lilly and Co's Cymbalta, or duloxetine; Solvay's Luvox, or fluvoxamine; GlaxoSmithKline Plc's Paxil, or paroxetine; Pfizer's Edronax or reboxetine; and Wyeth's Effexor, or venlafaxine, the study showed.
The team, which also found Remeron and Effexor were more effective than the other drugs, did not look at things like side-effects, toxicity, how well people functioned socially while on the treatments, or cost-effectiveness.
Remeron, or mirtazapine, comes from Dutch chemical group Akzo Nobel's Organon unit.
"The most important clinical implication of the results is that escitalopram and sertraline might be the best choice when starting a treatment for moderate to severe major depression because they have the best possible balance between efficacy and acceptability," the researchers wrote.
Most of the drugs were off-patent except for Cymbalta and Lexapro, the researchers said. They also analysed Wellbutrin XL, manufactured by Biovail, sold by Glaxo and known generically as bupropion and Cypress Bioscience Inc's Savella, or milnacipran .
The rights to that drug outside the United States are held by Pierre Fabre Medicament, the French company which developed the drug. Eli Lilly's Prozac, or fluoxetine, and Forest Laboratories Celexa, or citalopram, were also included.