The Montgomery Äsberg and the Hamilton ratings of depression: A comparison of measures

The 17-item Hamilton Rating Scale for Depression (HRSD17) and the Montgomery Äsberg Depression Rating Scale (MADRS) are two widely used clinician-rated symptom scales. A 6-item version of the HRSD (HRSD6) was created by Bech to address the psychometric limitations of the HRSD17. The psychometric properties of these measures were compared using classical test theory (CTT) and item response theory (IRT) methods. IRT methods were used to equate total scores on any two scales. Data from two distinctly different outpatient studies of nonpsychotic major depression: a 12-month study of highly treatment-resistant patients (n=233) and an 8-week acute phase drug treatment trial (n=985) were used for robustness of results. MADRS and HRSD6 items generally contributed more to the measurement of depression than HRSD17 items as shown by higher item-total correlations and higher IRT slope parameters. The MADRS and HRSD6 were unifactorial while the HRSD17 contained 2 factors. The MADRS showed about twice the precision in estimating depression as either the HRSD17 or HRSD6 for average severity of depression. An HRSD17 of 7 corresponded to an 8 or 9 on the MADRS and 4 on the HRSD6. The MADRS would be superior to the HRSD17 in the conduct of clinical trials.