How to Complete and Score the Hamilton Anxiety Rating Scale (HAM-A)

The Hamilton Anxiety Rating Scale, commonly abbreviated HAM-A, is a 14-item clinician-administered interview used to measure the severity of anxiety symptoms in patients already diagnosed with an anxiety disorder. Max Hamilton published it in 1959, and it remains one of the most widely used outcome measures in both clinical practice and research trials.¹ The form is in the public domain, and completing the interview takes roughly 10 to 15 minutes.²

The scale is a severity measure, not a screening tool or a diagnostic instrument. It assumes the anxiety diagnosis has already been made, and it quantifies how bad the symptoms currently are.

The 14 Items

Each item covers a cluster of related symptoms rather than a single complaint. The clinician rates every item on a five-point scale from 0 (not present) to 4 (very severe), so the form captures both breadth and intensity.¹ The items and their symptom clusters are:³

1. Anxious mood — worries, fearful anticipation, irritability, anticipation of the worst.
2. Tension — feelings of tension, startle response, being easily moved to tears, trembling, restlessness, fatigue, inability to relax.
3. Fears — of the dark, strangers, being left alone, animals, traffic, or crowds.
4. Insomnia — difficulty falling asleep, broken sleep, unsatisfying sleep, fatigue on waking, nightmares.
5. Intellectual (cognitive) — poor concentration and poor memory.
6. Depressed mood — loss of interest, lack of pleasure in hobbies, depression, early waking, diurnal mood swings.
7. Somatic (muscular) — aches, twitching, stiffness, teeth grinding, unsteady voice, increased muscle tone.
8. Somatic (sensory) — tinnitus, blurred vision, hot and cold flushes, feelings of weakness, prickling sensations.
9. Cardiovascular — rapid heartbeat, palpitations, chest pain, throbbing vessels, faintness, missed beats.
10. Respiratory — chest pressure or tightness, choking feelings, sighing, shortness of breath.
11. Gastrointestinal — difficulty swallowing, abdominal pain, nausea, bloating, loose bowels, constipation, weight loss.
12. Genitourinary — urinary frequency or urgency, menstrual irregularities, loss of libido, impotence.
13. Autonomic — dry mouth, flushing, pallor, sweating, dizziness, tension headache.
14. Behavior at interview — fidgeting, restlessness, hand tremor, furrowed brow, strained face, sighing, rapid breathing, facial pallor, swallowing.

Item 14 is different from the rest. It is scored entirely from what the clinician observes during the session, not from the patient’s self-report. The other 13 items blend the patient’s account with whatever the clinician notices.

Psychic and Somatic Subscales

The 14 items fall into two broad domains. Psychic anxiety covers the mental and emotional side of the condition; somatic anxiety covers the physical manifestations.¹ The convention most researchers follow places items 1 through 6 (anxious mood through depressed mood) in the psychic subscale and items 7 through 14 in the somatic subscale.

Tracking the two subscales separately is useful because a patient can score high on psychic items and low on somatic ones, or the reverse. A treatment that improves worry and fearfulness but does nothing for muscle tension or cardiovascular symptoms tells a different story than one that moves both subscales equally. Clinical trials often report the subscale scores alongside the total for this reason.

How Each Item Is Rated

Every item uses the same five-point scale.¹

0, not present. The patient denies the symptom and the clinician observes no evidence of it.
1, mild. The symptom is present but barely troublesome; occasional worry that does not interfere with daily activities is a typical example.
2, moderate. The symptom is clearly present and the patient reports noticeable distress or functional difficulty.
3, severe. The symptom causes significant distress or substantially limits the patient’s ability to function.
4, very severe. The symptom is incapacitating or dominates the patient’s experience.

The form does not spell out detailed anchors for each of the 14 items the way some newer instruments do. That leaves consistent scoring dependent on the clinician’s experience and judgment. When more than one rater will score the same patient, agreeing on anchor definitions during training helps prevent drift between raters.

Conducting the Interview

The HAM-A is meant to be completed during a face-to-face clinical interview, not handed to the patient as a self-report questionnaire. The clinician works through the 14 clusters, asking open-ended questions about the patient’s experience over a defined period, most commonly the past week. At the same time, the clinician watches for observable signs (fidgeting, rapid breathing, hand tremors, a furrowed brow) that feed directly into item 14 and can inform ratings elsewhere.

A structured interview guide called the SIGH-A exists to standardize the process, providing specific probe questions and guidance for borderline severity ratings. Research settings frequently require it to minimize variability between interviewers, though many clinicians in routine practice administer the scale without it.

A few practical points affect scoring consistency:

Set a clear time frame. Ask the patient how they felt over the past seven days rather than “lately.” A vague reference period produces vague answers.
Cover every item. Skipping one because the patient “doesn’t seem the type” introduces bias. Genitourinary complaints and autonomic signs are easy to miss if you don’t ask.
Separate what the patient says from what you see. A patient who insists they feel calm but is visibly trembling and swallowing repeatedly should score higher than a zero on item 14.
Record ratings during the interview. Scoring from memory afterward is less accurate, especially for items in the middle of the list that tend to blur together.

Calculating and Interpreting the Total Score

Add the ratings across all 14 items. The total can range from 0 to 56. The widely cited severity thresholds are:¹

Below 17: mild anxiety.
18 to 24: mild to moderate anxiety.
25 to 30: moderate to severe anxiety.
Above 30: severe anxiety.

These brackets give a quick snapshot, but the total alone does not tell the full story. Two patients can score 22 with very different profiles: one driven almost entirely by insomnia and cardiovascular symptoms, the other by anxious mood and cognitive difficulty. Reviewing individual item scores alongside the total reveals where the patient’s burden actually sits.

For treatment monitoring, the change in total score across visits matters more than any single assessment. A drop of several points between visits suggests the intervention is working. Many clinical trials define a “response” as a 50 percent or greater reduction from baseline and “remission” as a total score below a fixed cutoff, often 7 or 8.

Reliability and Known Limitations

The HAM-A holds up well on standard psychometric measures. A meta-analysis of studies using the scale found a mean internal consistency (Cronbach’s alpha) of 0.81, with individual study values ranging from 0.58 to 0.95. Test-retest reliability averaged 0.86, meaning scores stay fairly stable when the same patient is reassessed by the same clinician under similar conditions.⁴

The scale has recognized weaknesses. The most frequently cited is that it does not cleanly separate anxiety from depression. Item 6 explicitly assesses depressive symptoms like loss of interest and early waking, so a patient with comorbid depression will score higher even if their anxiety has not worsened. In treatment studies, this overlap makes it harder to tell whether a medication is reducing anxiety specifically or improving mood more broadly.⁵

The heavy weighting toward somatic symptoms is another concern. Eight of the 14 items cover physical complaints, which can inflate scores for patients who have unrelated medical conditions or are experiencing medication side effects. In a drug trial, a side effect like dry mouth or dizziness could paradoxically raise the anxiety score even when the medication is working.⁵ Clinicians aware of this can account for it when interpreting scores; the form itself builds in no correction.

Where to Get the Form

The original HAM-A is in the public domain.² Printable copies are freely available through academic institutions and government health repositories, including the University of Florida’s Department of Psychiatry.¹ No license is needed to use the English-language version in clinical practice or research.

Wiley offers a separate licensing service that covers linguistically validated translations, digital formatting, and integration into electronic data-capture platforms used in regulatory submissions.⁶ That service is aimed at pharmaceutical sponsors running multinational trials who need a certified translation and an audit-ready digital version. A clinician using the standard English form in everyday practice does not need to go through Wiley.

HAM-A Compared to the GAD-7

Clinicians sometimes ask whether the HAM-A or the GAD-7 is the better choice. They serve different purposes. The GAD-7 is a seven-item self-report questionnaire the patient fills out without clinician involvement. It works well as a fast screening tool; a patient in a primary care waiting room can complete it in under five minutes. The HAM-A requires a trained interviewer, takes 10 to 15 minutes, and captures a wider range of physical and psychological symptoms across its 14 domains.

Because the GAD-7 is self-reported, it reflects only what the patient is willing and able to describe. The HAM-A adds the clinician’s direct observations and professional judgment, which can pick up signs the patient underreports or does not recognize. For tracking outcomes in an ongoing treatment relationship or measuring change in a clinical trial, the HAM-A’s depth gives it an edge. For quick initial screening, or in settings where no trained interviewer is available, the GAD-7 is the practical choice.

Billing Considerations

Administering a standardized rating scale like the HAM-A during a clinical visit may be billed under CPT code 96127, which covers brief emotional or behavioral assessment with scoring and documentation. Medicare reimburses 96127 at roughly $5 per unit, with a limit of three units per visit. The code is not exclusive to the HAM-A; it applies to any standardized screening instrument that fits the description. If the assessment is part of a longer psychotherapy or evaluation session, clinicians typically bill the primary service code (such as 90834 for a 45-minute psychotherapy session) and add 96127 for the screening component when the payer allows it.

Payer rules on whether 96127 can be billed alongside other service codes vary. Some commercial plans bundle brief screening into the office visit and will not reimburse it separately, so checking with the specific insurer before submitting is the safest approach.

1
University of Florida Department of Psychiatry. Hamilton Anxiety Rating Scale (HAM-A)
2
National Center for Biotechnology Information. Hamilton Anxiety Rating Scale (HAM-A) – Intellectual Score
3
Lundbeck. Hamilton Anxiety Rating Scale (HAM-A)
4
ScienceDirect. A Meta-Analysis of the Psychometric Properties of the Hamilton Anxiety Rating Scale
5
PubMed. The Hamilton Anxiety Scale: Reliability, Validity and Sensitivity
6
Wiley. HAM-A: Hamilton Anxiety Scale