Background: Patients with treatment-resistant depression (TRD) have an increased mortality risk compared with other patients with depression, but it is not known how this translates into absolute numbers of excess deaths. Methods: Swedish national registers were used to identify a cohort of 118,774 antidepressant initiators 18–69 years old with a depression diagnosis. Patients who initiated a third consecutive treatment trial were classified as having TRD. Flexible parametric survival models were used to estimate the mortality risk due to all causes and external causes (suicides and accidents), comparing TRD patients with patients with other depression while adjusting for clinical and sociodemographic covariates and including interactions with TRD, age, and Charlson comorbidity index (CCI) for a number of somatic comorbidities. Standardized survival was estimated, as were numbers of excess deaths among TRD patients within each age and comorbidity category. Results: Compared with the mortality risk of other depressed patients, patients with TRD experienced excess deaths in most age and comorbidity categories in the range of 7–16 deaths per 1000 patients during 5 years. Highest numbers for all-cause excess deaths were found among patients 18–29 years old with CCI 1, where 16 [95% confidence interval 5–28] of the expected 37 [25–48] deaths per 1000 patients were excess deaths. The majority of the excess deaths were due to external causes. Conclusion: Patients with TRD experience significant numbers of excess deaths compared with other patients with depression.

Background Esketamine nasal spray was recently approved for treatment-resistant depression. The current analysis evaluated the impact of symptom-based treatment frequency changes during esketamine treatment on clinical outcomes. Methods This is a post-hoc analysis of an open-label, long-term (up to 1 year) study of esketamine in patients with treatment-resistant depression (SUSTAIN 2). During a 4-week induction phase, 778 patients self-administered esketamine twice weekly plus a new oral antidepressant daily. In responders (≥50% reduction in Montgomery-Åsberg Depression Rating Scale total score from baseline), esketamine treatment frequency was thereafter decreased during an optimization/maintenance phase to weekly for 4 weeks and then adjusted to the lowest frequency (weekly or every other week) that maintained remission (Montgomery-Åsberg Depression Rating Scale ≤ 12) based on a study-defined algorithm. The relationship between treatment frequency and symptom response, based on clinically meaningful change in Clinical Global Impression–Severity score, was subsequently evaluated 4 weeks after treatment frequency adjustments in the optimization/maintenance phase. Results Among 580 responders treated with weekly esketamine for the first 4 weeks in the optimization/maintenance phase (per protocol), 26% continued to improve, 50% maintained clinical benefit, and 24% worsened. Thereafter, when treatment frequency could be reduced from weekly to every other week, 19% further improved, 49% maintained benefit, and 32% worsened. For patients no longer in remission after treatment frequency reduction, an increase (every other week to weekly) resulted in 47% improved, 43% remained unchanged, and 10% worsened. Conclusions These findings support individualization of esketamine nasal spray treatment frequency to optimize treatment response in real-world clinical practice. Trial Registration ClinicalTrials.gov identifier: NCT02497287