Derivation of a definition of remission on the Montgomery-Asberg depression rating scale corresponding to the definition of remission on the Hamilton rating scale for depression.

During the past decade the Montgomery-Asberg Depression Rating Scale (MADRS) has been used with increasing frequency to measure outcome in antidepressant efficacy trials (AETs). In characterizing treatment outcome in AETs it is common to define treatment remission as a score below a predetermined cutoff score on the scale. Various cutoffs have been used to define remission on the MADRS. The goal of the present paper is to determine the cutoff on the MADRS that most closely corresponds to the cutoff most frequently used on the Hamilton Rating Scale for Depression to define remission. Three hundred and three psychiatric outpatients who were being treated for a DSM-IV major depressive episode were rated on the HRSD and the MADRS. A linear regression equation was computed to estimate MADRS scores from HRSD scores. After deriving the regression equation, we computed the MADRS score corresponding to an HRSD score of 7. We also examined the sensitivity, specificity and overall classification rate of the MADRS for identifying remission on the HRSD. Based on the equation from a linear regression analysis for the entire sample, a MADRS score of </=11 would correspond to a score of </=7 on the HRSD. We repeated the analysis after excluding the more severely depressed patients who currently met criteria for MDD, and based on the equation from this regression analysis a MADRS score of </=10 would correspond to a score of </=7 on the HRSD. In a complementary analysis, we examined the sensitivity, specificity and overall classification rate of the MADRS at different cutoff points for identifying remission, and found that a cutoff of </=10 maximized the level of agreement with the HRSD definition of remission. In conclusion, the regression equation relating HRSD and MADRS scores is dependent, in part, on the range and severity of scores in the sample. To facilitate comparisons of studies using the HRSD and MADRS our results suggest that a cutoff of 10 on the MADRS is equivalent to the HRSD cutoff of 7.