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The Montgomery-Åsberg Depression Rating Scale (MADRS) is a 10-item, clinician-administered questionnaire used to measure the severity of depressive symptoms, and it is the most common primary outcome measure in ketamine and esketamine clinical trials. Each item is scored from 0 to 6, producing a total score between 0 and 60, with higher scores indicating more severe depression. When you read a ketamine or Spravato (esketamine) study and see a phrase like "MADRS total score decreased by 12 points," the researchers are describing change on this specific scale.
Quick Answer
MADRS is a 10-item clinician-rated scale that scores depression severity from 0 to 60, with higher numbers meaning more severe symptoms. Ketamine and esketamine trials use it as the primary way to measure whether a treatment reduced depression, typically defining response as a 50% or greater drop from baseline and remission as a total score around 10 or lower. It's a research and clinical measurement tool, not a diagnosis on its own.
What MADRS Actually Measures
Psychiatrists Stuart Montgomery and Marie Åsberg developed the scale in 1979 specifically to be sensitive to treatment-related change, which is part of why it became a standard in antidepressant research, including modern ketamine studies. The 10 items cover symptoms such as apparent sadness, reported sadness, inner tension, reduced sleep, reduced appetite, concentration difficulties, lassitude, inability to feel, pessimistic thoughts, and suicidal thoughts. A trained rater scores each item during a structured interview, and the 10 scores are added together for the total.
Because MADRS focuses heavily on mood and cognitive-emotional symptoms rather than physical or somatic complaints, researchers consider it well suited to detecting the kind of rapid mood shifts ketamine can produce, which is one reason it shows up repeatedly across the ketamine and esketamine literature rather than being replaced by other depression scales.
Common MADRS Severity Ranges
How Ketamine Trials Use the MADRS Score
In a typical ketamine or esketamine trial, researchers record each participant's MADRS score at baseline, then again at set intervals after treatment, such as 24 hours, 72 hours, or several weeks later. The change between baseline and follow-up is the primary way trials quantify whether the treatment worked. Two terms come up constantly in this research:
- Response generally means the participant's MADRS total score dropped by 50% or more from baseline.
- Remission generally means the participant's MADRS total score fell to roughly 10 or below, indicating minimal residual symptoms.
These thresholds are conventions used across depression research broadly, not fixed rules written into a single regulation, so you may see slightly different cutoffs cited between studies. The FDA relied on MADRS score changes as a key efficacy measure in the clinical trials that supported esketamine's approval for treatment-resistant depression, and the scale continues to appear in peer-reviewed studies indexed on PubMed evaluating IV, intramuscular, and intranasal ketamine protocols. If you want a broader walkthrough of how to interpret outcome measures, effect sizes, and trial design in this research, see our guide on how to read ketamine depression research studies.
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A MADRS score is a snapshot of symptom severity at one point in time, not a diagnosis. It's most useful for tracking change, which is exactly why it's central to measuring ketamine's effects in clinical research.
MADRS vs. Other Depression Scales
MADRS is not the only depression scale used in mental health research, and understanding how it differs from the alternatives helps you interpret study results more accurately. The Hamilton Depression Rating Scale (HAM-D) is an older, clinician-administered scale that includes more items tied to sleep and physical symptoms, and it appears in some earlier ketamine research alongside or instead of MADRS. The Patient Health Questionnaire-9 (PHQ-9) is a self-report tool patients fill out themselves, commonly used in primary care and some clinic settings, but it's less frequently the primary endpoint in registration-track ketamine trials because self-report scales can be more susceptible to expectation effects, especially in studies where dissociative effects make it hard to keep participants unaware of which treatment they received.
None of these scales is more "correct" than another; they measure depression severity through different lenses, and researchers choose based on the trial's design and comparability to prior studies. When you're comparing outcome data across esketamine and generic ketamine studies, checking which scale each study used is a necessary step before comparing the numbers directly. Our esketamine vs. racemic ketamine comparison discusses how outcome measures like MADRS factor into route and formulation research.
Limitations of the MADRS Score
MADRS has real limits worth understanding before treating any single score as definitive. It requires a trained rater, so scoring can vary somewhat between clinicians. It also can't fully separate a genuine antidepressant effect from the acute perceptual changes ketamine produces, since some researchers have questioned whether the drug's dissociative effects could make it easier for participants or raters to guess they received active treatment rather than a placebo, a phenomenon called functional unblinding. That's a limitation of trial design generally, not a flaw unique to MADRS, but it's part of why researchers interpret single-study MADRS results cautiously and look for replication across trials.
MADRS also measures symptom severity at a moment in time; it doesn't capture how long an improvement lasts, which is why ketamine studies typically track scores across multiple follow-up points rather than relying on one reading. Understanding related concepts such as the sub-anesthetic dose used in depression research and the ketamine emergence reaction can help you interpret why a given trial reports the score changes it does.
Reading a MADRS Result in a Study
- Check the baseline MADRS score, not just the endpoint score, to gauge how severe symptoms were
- Look for whether the study reports 'response' (≥50% reduction), 'remission' (score ≈10 or below), or only mean score change
- Note the follow-up timepoint (24 hours vs. weeks) since ketamine's effects can shift over time
- Confirm whether MADRS was rated by a clinician or self-reported, since this affects reliability
- Compare against a placebo or active comparator arm rather than treating a single-arm result as proof of effect
Understanding related mechanisms can also add context to why MADRS scores move the way they do in ketamine research, including the default mode network and how ketamine disrupts depressive thought patterns, and how bioavailability affects ketamine absorption by route, since dosing and delivery method influence the timing and magnitude of symptom change researchers observe.
Explore More Ketamine Research Terms
The Ketamine Glossary breaks down clinical trial language, dosing terms, and safety terminology in plain English. This is educational content, not medical advice, talk with a licensed clinician about your own situation.
Frequently Asked Questions
Lower scores indicate less severe depression. A score of roughly 0-6 is generally considered the normal or remission range, while scores above 34 typically indicate severe depression. In treatment studies, a large drop from baseline is what matters most, not the absolute number alone.
No. MADRS measures the severity of depressive symptoms at a point in time; a diagnosis of major depressive disorder or treatment-resistant depression requires a full clinical evaluation by a licensed provider using diagnostic criteria, not a single scale score.
MADRS is heavily weighted toward mood and cognitive-emotional symptoms and was designed to be sensitive to treatment-related change, which researchers have found useful for detecting the relatively rapid symptom shifts associated with ketamine and esketamine.
No. A meaningful MADRS score reduction indicates measured symptom improvement during the study period, but it does not mean depression is permanently resolved. Ketamine's effects can be time-limited, and durability varies by individual and by treatment protocol.
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