Little is known about the clinical relevance of the Montgomery Asberg Depression Rating Scale (MADRS) total scores. It is unclear how total scores translate into clinical severity, or how commonly used measures for response (reduction from baseline of ≥50% in the total score) translate into clinical relevance. Moreover, MADRS based definitions of remission vary. We therefore compared: a/ the percentage and absolute change in the MADRS total scores with Clinical Global Impression – Improvement (CGI-I); b/ the absolute and percentage change in the MADRS total scores with Clinical Global Impression – Severity (CGI-S) absolute change. The method used was equipercentile linking of MADRS and CGI ratings from 22 drug trials in patients with Major Depressive Disorder (MDD) (n=3,288). Our results confirm the validity of the commonly used measures for response in MDD trials: a CGI-I score of 2 (‘much improved’) corresponded to a percentage MADRS reduction from baseline of 48% to 57%, and a CGI-I score of 1 (‘very much improved’) to a reduction of 80% to 84%. If a state of almost complete absence of symptoms were required for a reduction of the MADRS total score from baseline, little consensus exists about the definition of remission, where cut-offs points of ≤4 8, ≤ 9 8, ≤ 10 9,10, ≤ 12 11, of the MADRS have all been used. However, few studies have examined the validity of such cut-off points. They remain expert opinion–based definitions, so that an ACNP task force asked for validation studies 12. Furthermore, little is known about the clinical relevance of MADRS total scores in terms of their correspondence with clinically judged illness severity. In other words, how globally ill does a clinician judge someone to be who has a MADRS score of, for example, 20 or 30? How much does a clinician really notice a MADRS reduction of, say 50% of the patient’s baseline total score? The CGI was designed to give answers to these questions so that we decided to use it in an equipercentile linking analysis (see method section13). There is a lot of clinical utility in the ability to link such scales, as it allows the nominal translation of vast amounts of data into other scales, adding significantly to the available clinical data for various treatments without the need for new trials. This has already been shown to be possible and useful in the evaluation of clinical relevance of antipsychotics in schizophrenia and Transmagnetic Stimulation in major depression.

The purpose of this study was to find corresponding points for simultaneous MADRS and CGI ratings within a large sample of patients with Major Depressive Disorder (MDD) who were participating in drug trials following the methods of a previous analysis on the relationship between the HAMD 4 and the CGI 14.