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.