Outcome MeasureAnxiety

HAM-A

Hamilton Anxiety Rating Scale

20 Papers in Blossom

About This Instrument

The Hamilton Anxiety Rating Scale (HAM-A) is a 14-item clinician-administered questionnaire developed by Max Hamilton in 1959 to measure the severity of anxiety symptoms. Each item is rated on a 0–4 scale (0 = not present, 4 = very severe), yielding total scores from 0 to 56. The scale covers both psychic anxiety (anxious mood, tension, fears, cognitive symptoms, behavior at interview) and somatic anxiety (muscular, sensory, cardiovascular, respiratory, gastrointestinal, genitourinary, autonomic symptoms). The HAM-A is one of the earliest anxiety rating scales and remains widely used in pharmacological trials, including psychedelic research where anxiety is a co-occurring condition or treatment target. It has good interrater reliability and is often used alongside the HAM-D in studies examining both depression and anxiety outcomes.

Clinical Thresholds

056
Mild
Score 0–17
Moderate
Score 18–24
Severe
Score 25–56

Outcome Data Across Studies

Reported results for HAM-A across 14 studies with quantitative data.

Outcome data across 64 study arm–timepoint observations
SD
Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer
2016Primary
Low then high(experimental)02525.70.9—
Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer
2016Primary
Low then high(experimental)352516.61.50.001
Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer
2016Primary
Low then high(experimental)70248.91.1—
Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer
2016Primary
Low then high(experimental)182228.01.2—
Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer
2016Primary
High then low(experimental)02625.71.1—
Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer
2016Primary
High then low(experimental)35268.51.20.001
Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer
2016Primary
High then low(experimental)70257.51.3—
Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer
2016Primary
High then low(experimental)182247.01.2—
Ketamine’s dose-related effects on anxiety symptoms in patients with treatment refractory anxiety disorders
2017Secondary
Ketamine 0.25mg/kg(experimental)01226.0——
Ketamine’s dose-related effects on anxiety symptoms in patients with treatment refractory anxiety disorders
2017Secondary
Ketamine 0.25mg/kg(experimental)112———

Papers Using HAM-A

Open Accessindividual

LSD microdosing in major depressive disorder: results from an open-label trial

This open-label Phase IIa trial (n=19, 15 male) found that an 8-week regimen of microdosed LSD (8μg initially, then 6-20μg twice weekly) for major depressive disorder was well-tolerated with no serious adverse events or cardiac valvulopathy, achieved 59.5% reduction in MADRS scores sustained for six months, and had only one withdrawal due to anxiety.

Published
Journal
Neuropharmacology
Authors
Daldegan-Bueno, D., Donegan, C. J., Sumner, R. L., Forsyth, A., Evans, W. J., Alshakhouri, M., Reynolds, L. M, Roop, P., Ponton, R., Smith, T., Hoeh, N. R., Allen, N., Sundram, F., Menkes, D. B., Muthukumaraswamy, S.
Paywallindividual

Magnesium-ibogaine therapy effects on cortical oscillations and neural complexity in veterans with traumatic brain injury

This analysis of an open-label observational study (n=30) found that magnesium-ibogaine therapy in combat veterans with traumatic brain injury (TBI) led to slower brain wave patterns and reduced neural complexity on EEG, which correlated with improvements in PTSD, anxiety, and cognitive function at one-month follow-up.

Published
Journal
Nature Mental Health
Authors
Lissemore, J. I., Chaiken, A., Keller, C. J., Williams, N. R., Cherian, K. N., Buchanan, D., Espil, F., Keynan, J. N., Sridhar, M., Rolle, C. E., Saggar, M.
Paywallindividual

Long-term benefits of single-dose psilocybin in depressed patients with cancer

In a phase 2 trial of 30 cancer patients with major depressive disorder, a single 25 mg dose of psilocybin with psychological support produced robust antidepressant and anxiolytic effects maintained at two years. About 54% showed significant depression reduction (50% sustained) and roughly 46% showed significant anxiety reduction (43% sustained), suggesting a potentially paradigm‑changing alternative to traditional antidepressants.

Published
Journal
Cancer
Authors
Agrawal, M., Roddy, K., Jenkins, B., Leeks, C., Emanuel, |. E.
Open Accessindividual

Psilocybin therapy for mood dysfunction in Parkinson's disease: an open-label pilot trial

In an open‑label pilot of 12 people with mild–moderate Parkinson’s disease and comorbid depression/anxiety, two psilocybin doses combined with psychotherapy were well tolerated with no serious adverse events. Participants showed clinically meaningful, sustained improvements in depression and anxiety and gains in non‑motor, motor and select cognitive measures up to three months post‑treatment, indicating psilocybin therapy in PD warrants further study.

Published
Journal
Neuropsychopharmacology
Authors
Bradley, E. R., Sakai, K., Fernandes-Osterhold, G., Szigeti, B., Ludwig, C., Ostrem, J. L., Tanner, C. M., Bock, M. A., Llerena, K., Finley, P. R., O'donovan, A., Rafael, J., Zuzuarregui, P., Busby, Z., Mckernan, A., Penn, A. D., Wang, A. C. C., Rosen, R. C., Woolley, J. D.
Open Accessindividual

Effect of ketamine on anxiety: findings from the Ketamine for Adult Depression Study

In this secondary analysis of a multisite, double-blind RCT (n=174) in treatment‑resistant depression, subcutaneous racemic ketamine given twice weekly for 4 weeks at flexible, response‑guided doses (35-63mg/70kg) produced a significant short‑term reduction in anxiety (HAM‑A) versus midazolam, whereas a fixed low dose (35mg/70kg) did not. The anxiolytic effect was mediated by antidepressant response and was not maintained 4 weeks after the end of treatment.

Published
Journal
British Journal of Psychiatry
Authors
Mills, N. T., Nikolin, S., Glozier, N., Barton, D., Baune, B. T., Fitzgerald, P. B., Glue, P., Sarma, S., Rodgers, A., Hadzi-Pavlovic, D., Alonzo, A., Dong, V., Martin, D., Mitchell, P. B., Berk, M., Carter, G., Hackett, L., Somogyi, A. A., Mihalopoulos, C., Chatterton, M. L., Hood, S., Loo, C. K.
Open Accessindividual

Functional changes in sleep-related arousal after ketamine administration in individuals with treatment-resistant depression

In a randomized, double-blind crossover study of 36 people with treatment-resistant depression (TRD) and 25 healthy volunteers, ketamine altered the temporal dynamics of sleep EEG spectral power in TRD—producing earlier-night increases in delta power and later-night increases in alpha and delta. These spectral changes occurred without effects on sleep macroarchitecture (e.g. WASO, TST, REM latency), did not mediate ketamine’s antidepressant or anti‑suicidal effects, and baseline TRD showed lower total sleep time and shorter REM latency.

Published
Journal
Translational Psychiatry
Authors
Ballard, E. D., Greenstein, D., Reiss, P. T., Crainiceanu, C. M., Cui, E., Duncan, W. C., Hejazi, N. S., Zarate, C. A.

Quick Facts

Full Name
Hamilton Anxiety Rating Scale
Domain
Anxiety
Papers Indexed
20
Score Range
0–56
Interpretation
Lower = better
Unit
points
All Measures