Reference: Hamilton M.The assessment of anxiety states by rating. Br J Med Psychol 1959;32:50–55.

Rating Clinician-rated
Administration time 10–15 minutes
Main purpose To assess the severity of symptoms of anxiety
Population Adults, adolescents and children

Commentary
The HAM-A was one of the first rating scales developed
to measure the severity of anxiety symptoms, and is still
widely used today in both clinical and research settings.
The scale consists of 14 items, each defined by a series of
symptoms, and measures both psychic anxiety (mental
agitation and psychological distress) and somatic anxiety
(physical complaints related to anxiety). Although the
HAM-A remains widely used as an outcome measure in
clinical trials, it has been criticized for its sometimes poor ability to discriminate between anxiolytic and antidepressant effects, and somatic anxiety versus somatic side effects. The HAM-A does not provide any standardized
probe questions. Despite this, the reported levels of inter-
rater reliability for the scale appear to be acceptable.

Scoring
Each item is scored on a scale of 0 (not present) to 4
(severe), with a total score range of 0–56, where <17 indi-
cates mild severity, 18–24 mild to moderate severity and
25–30 moderate to severe.