What does it mean when a clinical trial fails? Probably not what you think.

Illustration © Eleanor Shakespeare, used by permission, all rights protected.

Today I published a story I’ve been working on, off and on, for exactly two years. “What Can We Learn When a Clinical Trial is Stopped” now online at both Mosaic and, as “Why a ‘Lifesaving’ Depression Treatment Didn’t Pass Clinical Trials“, at The Atlantic, looks at what a given clinical trial can and cannot tell us, and what it means when one fails.

I recommend you just go read the story — a strange one — at the site of your choice. But for those who like a teaser first  — the jacket copy, as it were — here you go:

I first wrote about neurologist Helen Mayberg’s innovative and rather radical depression treatment— the insertion of two humming electrodes deep into the brain — in the New York Times Magazine  back in 2006. At that point it was being hailed as the most promising advance in depression treatment in decades.

In 2008 the device maker St Jude, hoping to take the treatment to market, started a double-blinded trial designed to test it in 200 patients across North America.

In 2013 they very, very quietly halted it “for futility” after implanting only 90 patients. No data was released, no statements made about why. The silence was broken only in October 2017 — 9 years after the trial began — when The Lancet published the trial’s official report.

What happened? What does a “halt for futility” even mean? Why did the trial of such a promising treatment fail? What did it mean that it had? These seemingly simple questions actually proved quite hard to answer. Over the past two years, since I first heard about the halt, I’ve been working on answering them anyway. For the story on what I found, and what we can and can’t expect of clinical trials, see Mosaic or The Atlantic.