Background: The 17-item Hamilton Depression Rating Scale (HDRS) is used as a semi-gold standard in research. In treatment guidelines, the HDRS measurements serve to determine response and remission and guide clinical decision making for nonresponders. However, its use in clinical practice is limited, possibly because the HDRS is time consuming. In addition, the multidimensional HDRS is criticized for not measuring a unidimensional aspect as depression severity. The Maier and the Bech, two 6-item severity subscales extracted from the HDRS, are relatively unknown. This paper investigates whether the measurements obtained with these subscales are comparable with the original HDRS measurements. Methods: Data from 2 randomized controlled trials in 482 male and female patients, diagnosed with a major depression (with or without dysthymia) according to Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition, of whom 219 participated in the trials, were reanalyzed. A standardized stepwise psychopharmacological treatment was compared with a combination of pharmacotherapy with Short Psychodynamic Supportive Psychotherapy in a psychiatric outpatient department. Outcome measures were internal consistency and concurrent validity of HDRS, Maier, Bech, Clinical Global Impression scales, and Symptom Checklist depression subscale. Effect sizes of HDRS, Maier, and Bech were used to compare measured treatment effects for the randomized subjects participating in the trials. Item Response Theory was used to obtain conversion tables for the HDRS, Maier, Bech, and Symptom Checklist depression subscale. Results: We found moderate internal consistency (Cronbach a c 0.6-0.7) and high correlations of the Maier and Bech subscales with overall HDRS scores. Overall, there were no clinically relevant differences in effect sizes between Maier, Bech, and HDRS, although some differences were statistically significant. Receiver operating characteristic curves showed no difference between Maier and Bech to define remission but showed the Clinical Global Impression ratings to be unreliable. A cutoff V 4 corresponded with an HDRS V 7 criterion in both subscales. Conclusion: In clinical practice, both Maier and Bech scales can be used as equivalents of the HDRS, but will be more efficient. D