Lexapro, an antidepressant already approved to treat major depression in adults, has been approved by the U.S. Food and Drug Administration (FDA) to treat depression in children ages 12 to 17. This happened just weeks after the drug’s marker, Forest Laboratories, was charged by prosecutors of illegally marketing this and another drug (Celexa) to children and paying kickbacks to doctors for prescribing them.

Digging into the studies that resulted in the FDA’s approval demonstrates a clearly mixed picture of Lexapro’s effectiveness in children:

The FDA on Friday approved Lexapro’s use for adolescents based on favorable results in two clinical trials, one involving adolescents taking Lexapro and another involving children and adolescents taking chemically similar Celexa, Forest said.

But effectiveness was not shown in another pair of studies, Forest said, one a Lexapro trial involving patients aged 7 to 17 and the other a study of Celexa in adolescents.

Moreover, the company said on Friday that Lexapro’s ability to maintain control of symptoms in adolescents had not been demonstrated.

But the FDA concluded that maintenance efficacy can be “extrapolated” from adult data and from comparisons of how Lexapro is absorbed among adults and adolescents, Forest said.

“A lot of these kinds of trials are not successful because it’s very difficult to do depression studies,” said Forest spokesman Frank Murdolo.

“But we have two studies that were successful” and will provide patients another treatment option, Murdolo said.

Ahhh, so you have 2 studies that show effectiveness and 2 that do not, and you still approve because, according to Forest, “it’s very difficult to do depression studies”?! That’s the strangest rationale I’ve ever heard from a pharmaceutical company defending its product’s less-than-stellar data.

And this comes after the FDA had previously declined to approve Lexapro’s older cousin drug, Celexa, for the same indicated use in children. Is Lexapro better? According to the company’s own research, that’s not at all clear.

Why the FDA felt approval of this additional use of the drug was warranted is not clear. When presented with mixed research results, I would tend to err on the side of caution and say, “Well, you really haven’t demonstrated this drug’s benefits in this population.” But I’m not the FDA, and I guess scientists there see things differently.

Read the full article: Depression pill OK’d for kids but probe goes on