The Hamilton Anxiety Rating Scale (HAM-A, sometimes termed HARS) [ 1], dating back to 1959, is one of the first rating scales to measure the severity of perceived anxiety symptoms. It is still in use today, being considered one of the most widely used rating scales, and has been translated into Cantonese, French and Spanish. It has been used as a benchmark for more recently devised scales [ 2–4].
The author’s original intent for this scale was for its use in individuals with anxiety neurosis (in contrast to the anxiety inherent in the response to a threat or stress)—i.e. not a means of diagnosing anxiety concomitant with other pathology or problems. One year later, Hamilton also published a similar scale for depressive symptoms [ 5].
The HAM-A is a clinician-based questionnaire; however, being available in the public domain, it has been employed as a self-scored survey. It consists of 14 symptom-defined elements, and caters for both psychological and somatic symptoms, comprising anxious mood; tension (including startle response, fatigability, restlessness); fears (including of the dark/strangers/crowds); insomnia; ‘intellectual’ (poor memory/difficulty concentrating); depressed mood (including anhedonia); somatic symptoms (including aches and pains, stiffness, bruxism); sensory (including tinnitus, blurred vision); cardiovascular (including tachycardia and palpitations); respiratory (chest tightness, choking); gastrointestinal (including irritable bowel syndrome-type symptoms); genitourinary (including urinary frequency, loss of libido); autonomic (including dry mouth, tension headache) and observed behaviour at interview (restless, fidgety, etc.). Each item is scored on a basic numeric scoring of 0 (not present) to 4 (severe): >17/56 is taken to indicate mild anxiety; 25–30 is considered moderate–severe.
As to efficacy, although it is still often used in clinical research trials (both of medication and psychological interventions), it has been criticized [ 6] for its apparent inaccuracy in discriminating between anxiolytic or antidepressant effects, and between somatic anxiety compared to side-effects—thus, the authors concluded that it was of limited usage in the evaluation of anxiolytics. Maier et al. [ 6] tested the scale’s reliability and validity in two samples of 97 anxious and 101 depressed individuals and concluded that the reliability and concurrent validity of the HAM-A and its subscales were sufficient: there is reasonable inter-rater reliability and good one-week retest reliability.
More recently [ 7], it has been pointed out that the way clinicians assess symptom severity may reduce the reliability of the original semistructured assessment. Therefore, a structured interview guide (the Hamilton Anxiety Rating Scale Interview Guide (HARS-IG), standardizing the interview questions) was developed and evaluated by joint interview and test–retest in 30 inpatients. HARS-IG has emerged as a more reliable assessment tool than the original.
How does this relate to occupational practice? The research applications are more evident: it has been used in a number of occupational health-related studies [ 8] and to measure the efficacy of occupational therapy.
And for the consulting room? It is reported to take 12–15min to administer—longer than the Hospital Anxiety and Depression Score—and is considered to be of more use as a monitoring tool (i.e. for sequential testing) than as a single-use diagnostic or screening test. The length of time to administer, the experience and training needed, may make this test less practical for everyday clinical practice.
The questionnaire and operating instructions are freely available on the internet [ 9].