Effectiveness and factors associated with esketamine response during the 4-week induction period for treatment-resistant depression: post-hoc analysis of the real-world ESKALE study.
Journal of psychiatric research June 1, 2026 Ludovic Samalin, Maud Rothärmel, Lila Mekaoui et al.
In patients with treatment-resistant depression, depressive symptoms improved rapidly during the first four weeks of intranasal esketamine treatment. Among 128 patients in a French real-world study, the average depression rating score fell by 7.5 points after one week and by 13.5 points after four weeks. The proportion of patients whose score dropped by at least half rose from 19.4% at week 1 to 47.4% at week 4. Experiencing dissociation during the first week was linked to a threefold higher chance of response at week 1, but no other factors predicted response. The findings suggest early dissociation may play a role in treatment response, but more research is needed on prognostic factors.