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T69

THE MCINTYRE AND ROSENBLAT RAPID RESPONSE SCALE (MARRRS): A PSYCHOMETRIC EVALUATION OF PATIENTS WITH TREATMENT-RESISTANT BIPOLAR DEPRESSION

Nelson Rodrigues — Roger S. McIntyre2, Diana Orsini3, Sara Di Luch3, Gabrielle Lovell3, Shreya Vasudeva3, Rodrigo Mansur3, Joshua D Rosenblat3 1University of Windsor, 2University Health Network, University of Toronto, 3University of Toronto

2026 ASCP Annual Meeting

Background

A foundational assumption of measurement-based care is that the outcome instruments are validated within relevant populations and are sensitive to patient symptomatology. Extant depression severity scales were initially developed and validated in the context of monoaminergic antidepressants, which assess symptom change over a twoweek interval (Rush and Thase, 2018). Initial evidence suggests that the McIntyre and Rosenblat Rapid Response Scale (MARRRS) is sensitive to rapid-acting treatments, particularly intravenous ketamine (McIntyre et al. 2021). The present analysis provides evidence validating the MARRRS for patients with treatment-resistant bipolar I/II depression (TRBD).

Methods

Adults with TRBD were enrolled in a multi-site, randomized, midazolamcontrolled clinical trial, receiving four flexibly dosed infusions of ketamine (0.5 - 0.75 mg/kg) or midazolam (0.02 – 0.03 mg/kg) over two weeks. Depressive symptoms were measured using the Montgomery–Åsberg Depression Rating Scale (MADRS), which was administered by trained study personnel at each study visit. Additionally, participants completed the MARRRS at the same visits. The MARRRS is a 14-item self report questionnaire that evaluates depressive symptoms over a 72-hour period. Each item is scored on a 4-point ordinal scale, with the total score ranging from 0, indicating an absence of symptoms, to 42, indicating a more severe depressed state.

Results

Sixty-eight participants (Mage = 44.5 ± 11.6) were enrolled in the study. There was a significant infusion by group interaction (F (35, 667.3) = 2.3, p < .001) on the MARRRS, controlling for the effects of sex and diagnosis. The between group difference at the twoweek primary endpoint was -3.8 (95% Confidence Interval (CI): -8.2 to 0.7; p = 0.09). The MARRRS had a high internal consistency across all study visits (0.89 to 0.95). There was significant convergent validity between the MADRS and MARRRS across all study visits (r (1038) = .84, p < .001). The area under the curve for the MARRRS against the standard MADRS remitter cut-off (i.e., MADRS ≤ 10) indicated excellent classification accuracy (AUC = .94, 95% CI: .91 to .96, p < .001). Evaluation of remission thresholds indicated that a MARRRS cut-off score of 11 provided the best balance between sensitivity (77%) and specificity (94%). Exploratory factor analysis identified a two-factor structure for the MARRRS (dysphoria and psychic anxiety), which accounted for 64.9% of the variance.

Discussion

This analysis represents the first use of the MARRRS to assess depressive symptomatology within a randomized controlled trial and suggests that the self-report measure is valid for patients with TRBD receiving intravenous ketamine. The MARRRS was validated against a clinician-rated measure of depressive severity (i.e., the MADRS) and demonstrated strong sensitivity to depressive symptoms, excellent classification accuracy, and high inter-item reliability. To enhance clinical utility, a cut-off score of 11 on the MARRRS was identified as reliably distinguishing remitters from non-remitters. Overall, these findings support the use of the MARRRS as a pragmatic tool for monitoring rapid antidepressant response.