A third of the FDA-registered antidepressant trials were never published; the published ones looked twice as positive
Of 74 FDA-registered antidepressant trials, 31 percent were unpublished. "According to the published literature, it appeared that 94% of the trials conducted were positive. By contrast, the FDA analysis showed that 51% were positive."
Suggestive but preliminary. Not settled. how we score evidence
Caveat on this rating: The judgement that 11 studies were "published in a way that, in our opinion, conveyed a positive outcome" is the authors' reading, and the study covers approvals from 1987 to 2004; the 2022 update finds the gap narrower for newer drugs.
Doctors and patients read journals. The FDA reads everything the company submitted. This is what the gap between the two looked like for antidepressants.
Significant findings
Turner and colleagues (New England Journal of Medicine, 2008) obtained the FDA reviews for "studies of 12 antidepressant agents involving 12,564 patients" and searched for matching publications. "Among 74 FDA-registered studies, 31%, accounting for 3449 study participants, were not published. Whether and how the studies were published were associated with the study outcome."
"A total of 37 studies viewed by the FDA as having positive results were published; 1 study viewed as positive was not published. Studies viewed by the FDA as having negative or questionable results were, with 3 exceptions, either not published (22 studies) or published in a way that, in our opinion, conveyed a positive outcome (11 studies)."
The headline: "According to the published literature, it appeared that 94% of the trials conducted were positive. By contrast, the FDA analysis showed that 51% were positive. Separate meta-analyses of the FDA and journal data sets showed that the increase in effect size ranged from 11 to 69% for individual drugs and was 32% overall."
The authors do not assign blame: "We cannot determine whether the bias observed resulted from a failure to submit manuscripts on the part of authors and sponsors, from decisions by journal editors and reviewers not to publish, or both."
Worth asking
Two readings, both true. The drugs still beat placebo in the FDA's own complete data set; this paper is about the size of the effect, not whether there is one. And a doctor who read only the journals in 2008 believed antidepressants worked about a third better than the regulator's evidence showed. The 2022 follow-up in this wave asks whether that improved.
Source
Selective publication of antidepressant trials and its influence on apparent efficacy — Turner EH, Matthews AM, Linardatos E, Tell RA, Rosenthal R (2008)
Top-tier peer-reviewed journal
Read the source: https://doi.org/10.1056/NEJMsa065779
DOI: 10.1056/NEJMsa065779
How this was scored
- Study design
- Cross-sectional study / survey
- Funding
- Funding not disclosed
- Published in
- Top-tier peer-reviewed journal
- Sample size
- 12,564
- Preregistered
- not recorded
- Conflicts disclosed
- not recorded
- Independent of proponent
- not recorded
- Retracted
- No
Read the full scoring rubric, including what it can't tell you.
Published September 21, 2026.
Questions
How strong is the evidence behind this?
veisund rates this source "early signal". Suggestive but preliminary. Not settled. It scores 50 out of 100 on our published rubric. One caveat travels with that badge: The judgement that 11 studies were "published in a way that, in our opinion, conveyed a positive outcome" is the authors' reading, and the study covers approvals from 1987 to 2004; the 2022 update finds the gap narrower for newer drugs. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
Selective publication of antidepressant trials and its influence on apparent efficacy — Turner EH, Matthews AM, Linardatos E, Tell RA, Rosenthal R (2008). Published in: Top-tier peer-reviewed journal. DOI: 10.1056/NEJMsa065779. The full source is linked on this page so you can read it yourself.
Who paid for this research, and does that matter?
Study design: Cross-sectional study / survey. Funding: Funding not disclosed. Independence from the proponent is not recorded. Industry sponsorship is one of the most reliably measured biases in medicine, which is why funding carries real weight in the score rather than sitting in a footnote.
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.