Résumé
Background: Esketamine has been shown to produce a major antidepressant response inpatients with treatment-resistant depression (TRD). We aimed to evaluate the factors associatedwith achieving remission in these individuals.Methods: The study was carried out across four psychiatry departments in Madrid, Spain.Patients aged over 18 years were included if they received esketamine as an augmentationtreatment for TRD. Standard esketamine protocol included an induction phase (2administrations per week for 4 weeks) and a maintenance phase (1 administration per week for5 to 8 weeks). A subsequent treatment continuation phase was also proposed. Clinical data andscores at the Clinical Global Impression scales were measured following each esketamineadministration.Results: Sixty-five patients initiated the treatment, and 45 patients (69.2%) completed thestandard protocol. The median number of esketamine administrations was 19. The mean age ofthe sample was 53.09 and 52.3% of the patients were females. Out of the whole sample, 36(55%) of the patients achieved remission over the follow-up. Remission rates elevated to 67%in those who completed the standard protocol, and to 70% in those having received more than19 esketamine administrations. Achieving remission over the follow-up was associated withthe absence of dissociative symptoms, and with completing the standard esketamine protocol(OR=0.229, p=0.045; and OR=4.538, p=0.025, respectively). Receiving more than 19esketamine administrations was associated with remission over the follow-up (OR=6.513,p=0.006).Conclusions: Our results suggest that extending the numbers of esketamine administration mayincrease the chances to obtain remission. Adverse effects did not impact the treatment course.