HAM-D: Hamilton Depression Rating Scale
The HAM-D (Hamilton Depression Rating Scale) is a 17-item clinician-rated scale that measures the severity of depressive symptoms over the past week through a semi-structured interview. The benchmark outcome measure in antidepressant clinical trials, with ≤7 as the remission criterion.
HAM-D Score Interpreter
Scores 8–16 indicate mild depressive symptoms. Monitoring and low-intensity interventions may be appropriate depending on clinical context.
17 items; clinician-rated via semi-structured interview covering the past week. Items scored 0–4 or 0–2 depending on the symptom. Total range 0–52.
| Total score (HAM-D17) | Interpretation |
|---|---|
| 24+ | Severe depressionScores ≥24 indicate severe depressive illness. Clinically significant impairment is expected; urgent evaluation and treatment review are warranted. |
| 17–23 | Moderate depressionScores 17–23 indicate moderate severity. This range typically meets the minimum threshold for entry into antidepressant efficacy trials. |
| 8–16 | Mild depressionScores 8–16 indicate mild depressive symptoms. Monitoring and low-intensity interventions may be appropriate depending on clinical context. |
| 0–7 | Remission / minimal symptomsScores 0–7 reflect the consensus remission criterion. Residual symptoms may still be present; continued monitoring supports relapse prevention. |
Zimmerman M et al. (2013). J Affect Disord. 150(2):384-8. Severity ranges per empirically derived ROC-based cutoffs. Remission criterion per Frank E et al. (1991). Arch Gen Psychiatry. 48(9):851-5. Educational reference only — not a diagnostic tool.
For reference only — not an assessment, diagnosis, or medical advice. This page provides scoring reference material; interpretation and clinical decisions rest with a qualified clinician.
The HAM-D (HDRS) is the criterion-standard 17-item observer-rated scale for measuring depression severity. The benchmark outcome measure in 1,000+ antidepressant clinical trials and the standard for establishing treatment response and remission.
What the HAM-D measures
The HAM-D (Hamilton Depression Rating Scale), also called the HDRS or HRSD, is a 17-item clinician-administered rating scale developed by Max Hamilton in 1960 to quantify the severity of depressive illness. It is one of the most widely used observer-rated scales for measuring depression in pharmacological research and has been used as the primary outcome measure in the majority of antidepressant clinical trials.
Items assess mood, guilt, suicidality, insomnia, work and activity, psychomotor retardation, agitation, anxiety, somatic symptoms, and vegetative features including appetite, libido, and weight. It is particularly sensitive to melancholic features. The HAM-D measures the severity of depressive symptoms in people already identified as depressed; it is not a diagnostic tool.
How to administer the HAM-D
The HAM-D is administered by a trained clinician through a semi-structured interview, with ratings based on observed behaviour and reported symptoms. It captures symptoms over the past week. Patient self-completion is not valid, so it cannot substitute for a self-report questionnaire such as the PHQ-9 in routine screening workflows.
For educational reference only. HAM-D is clinician-administered, scores should be derived from a structured clinical interview, not self-report.
HAM-D scoring and interpretation
Items are rated on either a 5-point scale (0–4) or a 3-point scale (0–2), depending on the symptom. The 17-item version (HAM-D17) is standard, yielding total scores from 0 to 52.
HAM-D17 severity ranges recommended by Zimmerman et al. (2013):
| Total score | Severity |
|---|---|
| 0–7 | No depression |
| 8–16 | Mild depression |
| 17–23 | Moderate depression |
| ≥24 | Severe depression |
A ≥50% reduction from baseline defines treatment response; a score of ≤7 defines remission (Frank et al., 1991), the two endpoints that anchor FDA antidepressant approval trials. A score of ≤7 reflects minimal residual symptoms but does not confirm full functional recovery.
HAM-D vs PHQ-9
Both measure depression severity, but they serve different purposes and settings.
- Patient-completed, no clinician time required
- 9 items, fast for routine screening
- Ideal for primary care and high-volume settings
- CPT billable (96127 with modifier) when used for MBC
- Not accepted as primary endpoint in pharma trials
- Observer-rated, captures behavioural signs, not just subjective report
- Criterion standard for antidepressant clinical trials (FDA)
- Sensitive to melancholic features (vegetative symptoms)
- Remission criterion (≤7) widely accepted in research
- Requires trained clinician, not suitable for patient self-report
Psychometric properties
- Severity cutoffs. In 627 outpatients with major depressive disorder, ROC analysis against clinician CGI severity ratings found the HAM-D17 cutoffs that best separated mild from moderate depression (17) and moderate from severe depression (24) (Zimmerman et al., 2013).
- Scalability and versions. In a placebo-controlled antidepressant trial, the brief 6-item HAM-D6 was superior to the HAM-D17, HAM-D21 and HAM-D24 in scalability and in separating drug from placebo remission rates; longer versions showed smaller discriminating validity (Kyle et al., 2016).
Limitations
- Not diagnostic. The HAM-D quantifies severity in people already identified as depressed; diagnosis requires a structured clinical assessment.
- Clinician time and training. It requires a trained rater and a semi-structured interview, so it is impractical for high-volume screening.
- Multidimensional total. Longer versions add items that weaken their ability to separate drug from placebo; the 6-item core scale performed better in one trial (Kyle et al., 2016).
- Cutoff generalizability. The severity ranges come from a single outpatient practice whose patients were mostly white, female and insured (Zimmerman et al., 2013).
Measuring Depression in HiBoop
HiBoop does not offer the HAM-D; this page is reference material. For depression, HiBoop offers the PHQ-9 and PHQ-8, scored on submission and tracked over time.
HiBoop does not offer this scale. This page is reference material.This library is an academic and clinical reference. A scale described here is not necessarily offered in HiBoop; each page says whether it is.
Bill this assessment
In the US, the HAM-D: Hamilton Depression Rating Scale is usually billed under these CPT codes. Payer rules vary.
Measurement-based care in practice
For clinicians
HiBoop does not offer this scale. For the scales it does offer, responses are scored on submission and tracked over time, and HiBoop automates delivery across your patient panel.
For individuals
This page is a clinical reference, not a diagnostic tool. If you have concerns about your own symptoms, bring this information to a qualified mental health professional.
Frequently Asked Questions
Is the HAM-D self-report or clinician-administered?
The HAM-D is clinician-administered, not a self-report measure. A trained clinician conducts a semi-structured interview and assigns ratings based on observed behaviour and reported symptoms. Because patient self-completion is not valid, it cannot substitute for the PHQ-9 in routine screening workflows.
What does a HAM-D score of 7 or below mean?
A score of ≤7 is the consensus remission criterion established by Frank et al. (1991) and widely adopted as the FDA benchmark in antidepressant approval trials. It reflects minimal residual symptoms, though it does not confirm full functional recovery or absence of future recurrence risk.
How is response defined on the HAM-D?
Treatment response is conventionally defined as a ≥50% reduction from the baseline HAM-D score. This threshold, alongside the ≤7 remission criterion, forms the dual-endpoint standard used by regulatory agencies when evaluating antidepressant efficacy in randomized controlled trials.
References
- 1.Hamilton M. A rating scale for depression. J Neurol Neurosurg Psychiatry. 1960;23(1):56-62.View source
- 2.Frank E, Prien RF, Jarrett RB, Keller MB, Kupfer DJ, Lavori PW, Rush AJ, Weissman MM. Conceptualization and rationale for consensus definitions of terms in major depressive disorder. Arch Gen Psychiatry. 1991;48(9):851-5.View source
- 3.Zimmerman M, Martinez JH, Young D, Chelminski I, Dalrymple K. Severity classification on the Hamilton Depression Rating Scale. J Affect Disord. 2013;150(2):384-8.View source
- 4.Kyle PR, Lemming OM, Timmerby N, Søndergaard S, Andreasson K, Bech P. The validity of the different versions of the Hamilton Depression Scale in separating remission rates of placebo and antidepressants in clinical trials of major depression. J Clin Psychopharmacol. 2016;36(5):453-6.View source
Last reviewed: Jun 3, 2026
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