Trick question: They’re all equally effective.

That’s the conclusion a panel of experts came to after analyzing the results of more than 200 studies, and their finding forms the backbone of new guidelines out this week from the American College of Physicians (a professional society for primary-care docs).

The guidelines suggest choosing based on costs, patient preference and differences in side-effect risks.

The guidelines look at so-called second-generation antidepressants, which work by changing the brain’s uptake of naturally occurring chemicals such as serotonin. If you’ve heard of a name-brand antidepressant — Pfizer’s Zoloft, Eli Lilly’s Prozac or Forest’s Celexa — it’s probably in this group.

But despite all the marketing the companies did to push these drugs during their patent-protected heydays, the authors found “no substantial differences in comparative efficacy” between the drugs’ ability to treat depression. The finding applies across multiple phases of treatment; to patients with depression and symptoms, such as anxiety; and to subgroups such as those defined by age and sex.

There are a few differences in terms of side effects. GlaxoSmithKline’s Wellbutrin, for example, appears less likely to cause sexual dysfunction than certain other antidepressants. Overall, though, the side effects risks are pretty similar across the category.

On the question of suicidal thoughts or behaviors, a frequently discussed side effect associated with these medicines in some studies, the authors found that “no particular drug has an excess risk compared with any other drug in this class.”

Source: The Wall Street Journal

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