The sensitivity of the Mini-Mental State Examination to detect objective cognitive side-effects induced by electroconvulsive therapy: results from the Dutch ECT Consortium

Background: Monitoring cognitive side effects following electroconvulsive therapy (ECT) is crucial for balancing side effects and clinical effectiveness. Yet, evidence-based guidelines on cognitive testing following ECT are lacking. A frequently used test in global ECT practice is the Mini-Mental State Examination (MMSE). We examined the change of the MMSE score and its performance in identifying a decline in predefined neuropsychological measures sensitive to ECT-induced cognitive changes: verbal recall and verbal fluency. Methods: Mean MMSE scores before and 1 week after ECT were compared using a Wilcoxon signed rank test. The Reliable Change Index was calculated for all cognitive measures to indicate whether a participant's change in score from pre- to post-ECT was considered statistically significant. The sensitivity and specificity of the MMSE were calculated. Results: A total of 426 patients with depression from 5 sites were included from the Dutch ECT Consortium. Mean (SD) MMSE score increased significantly from 26.2 (3.9) before ECT to 26.8 (3.8) after ECT (p = .002). After ECT, 36 patients (8.5%) showed a significant decline in MMSE score. The sensitivity of the MMSE in identifying patients who experienced a significant decline in verbal recall or verbal fluency ranged from 3.6% to 11.1%. The specificity of the MMSE in identifying patients who did not experience a significant decline in verbal recall or verbal fluency ranged from 95.6% to 96.6%. Conclusions: Given the very low sensitivity of the MMSE, we propose reconsidering the prominence of the MMSE in ECT practice and cognitive monitoring guidelines, advocating for a more comprehensive approach to assess ECT-induced cognitive changes.