Table 2.
Characteristics of observational studies included in the systematic review.
| Author, Year | Study Design | Population Study | Main Outcomes | Duration | Study Drug | Main Findings |
|---|---|---|---|---|---|---|
| Estrade et al., 2023 [43] |
OS | 105 MDD patients with TRD | Define trajectories of ESK response using MADRS score | 5 months | IN ESK 28–84 mg | After two ESK administrations, the MADRS score predicted the 90-day trajectories of response with an accuracy of 80%. |
| Singh et al., 2023 [44] |
OS | 62 MDD patients with TRD | Change in QIDS-SR score and time to achieve response and remission | Up to 6 weeks | Ketamine IV 0.5 mg/kg vs. IN ESK 56–84 mg | There was no significant difference in response and remission rates between IV and IN routes. A significantly faster time to remission was observed in the ketamine IV group compared to the IN ESK group (HR = 5.0, p = 0.02). |
| Brendle et al., 2022 [45] |
OS | 171 MDD patients | Change in GAD-7 and PHQ-9 scores | 1 to 71 treatment sessions | IN ESK 56–84 mg | Significant reduction in PHQ-9 and GAD-7 scores was observed between baseline and last available treatment (PHQ-9 = mean [SD]: 16.7 [5.82] vs. 12 [6.38], p < 0.001; GAD-7 = mean [SD]: 12.0 [5.8] vs. 8.7 [5.62], p < 0.001). |
| Martinotti et al., 2022 [46] |
OS | 116 MDD patients with TRD | Change in MADRS score and response and remission rates | 3 months | ESK 28–84 mg | Significant improvement in MADRS score was observed at months 1 (T1) and 3 (T2) (Student t-test baseline vs. T1: t −15.79, p < 0.0001; T2 vs. baseline: t 18.07, p < 0.0001). |
| Samalin et al., 2022, [47] |
OS | 66 MDD patients with TRD | Characteristics of TRD patients receiving IN ESK, change in MADRS score | 30 days (median treatment exposure) | ESK 28–84 mg | A decrease in MADRS score by 36% was observed from baseline to week 4 (mean MADRS score: 30.9 vs. 19.5, respectively). |
Abreviations: ESK: esketamine; GAD: general anxiety disorder; HR: hazard ratio; IN: intranasal, IV: intravenous; MADRS: Montgomery–Asberg Depression Rating Scale; MDD: major depressive disorder; OS: observational study; PHQ-9: patient health questionnaire; QIDS-SR: Quick Inventory of Depressive Symptomatology-Self Report; SD: standard deviation; TRD: treatment-resistant depression.