The depression scale in drug trials was built from drug trials, to be sensitive to treatment
The Montgomery-Åsberg scale kept the ten items that changed most across 64 patients in studies of four antidepressants. Its authors say it was designed to be sensitive to treatment effects. It is the endpoint the FDA reads.
We have not finished checking this source. No judgement either way. how we score evidence
Caveat on this rating: Sensitivity to change is a legitimate design goal for a trial endpoint and the authors state it openly; the point is transparency about what an approval number measures, not an accusation.
Significant findings
When the FDA approves an antidepressant, the number it reads is usually a change on one of two clinician-rated scales: Hamilton's from 1960, or Montgomery and Åsberg's from 1979. Neither is the form you fill in at a clinic. Both define what "response" and "remission" mean in the trials that get drugs approved.
The 1979 paper describes its own construction. Ratings of 54 English and 52 Swedish patients on a 65-item scale were used to find the seventeen most common symptoms. Then, in the authors' words, "Ratings on these 17 items for 64 patients participating in studies of four different antidepressant drugs were used to create a depression scale consisting of the 10 items which showed the largest changes with treatment and the highest correlation to overall change." The scale was, again in its own words, "designed to be particularly sensitive to treatment effects."
That is not a scandal. A trial endpoint has to be able to move. It is worth knowing: the yardstick was chosen for its ability to register drug effects, and a drug's approval rests on movement along that yardstick, in trials that typically run weeks.
Worth asking
The clinic measures you on the PHQ-9. The trial measured the drug on the MADRS. They correlate, and they are not the same thing. If a prescriber quotes a trial result, it is fair to ask what scale it was measured on and over how many weeks.
Source
A new depression scale designed to be sensitive to change — Montgomery SA, Åsberg M (1979)
Read the source: https://doi.org/10.1192/bjp.134.4.382
DOI: 10.1192/bjp.134.4.382
How this was scored
- Study design
- not recorded
- Funding
- not recorded
- Published in
- not recorded
- Sample size
- not recorded
- Preregistered
- not recorded
- Conflicts disclosed
- not recorded
- Independent of proponent
- not recorded
- Retracted
- No
We have not finished checking this source, so there is no scoring to show yet. “We have not checked this yet” and “this is disputed” are different statements, so no scored band is shown rather than a low one.
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Published September 17, 2026.
Questions
How strong is the evidence behind this?
veisund rates this source "not yet assessed". We have not finished checking this source. No judgement either way. One caveat travels with that badge: Sensitivity to change is a legitimate design goal for a trial endpoint and the authors state it openly; the point is transparency about what an approval number measures, not an accusation. 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?
A new depression scale designed to be sensitive to change — Montgomery SA, Åsberg M (1979). DOI: 10.1192/bjp.134.4.382. The full source is linked on this page so you can read it yourself.
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.