Background: Suicidal ideation (SI) represents a clinical challenge in patients with treatment-resistant depression (TRD), and the management of this condition should be as rapid and effective as possible. Intranasal Esketamine has shown promise in patients with TRD due to its rapid onset of action on both SI and depressive symptoms. Since this medication has been recently approved, real-world data on its efficacy remain scarce, and little is known about which patients are most likely to benefit from this approach. Aims: This study aimed (1) to evaluate the efficacy of intranasal Esketamine on SI and depressive symptoms and (2) to find potential predictors of clinical response. Methods: Patients with TRD who received intranasal Esketamine were included in this study. Clinical evaluations and psychometric assessments were made at baseline (T0) and at five subsequent time points (one week [T1], one month [T2], two months [T3], three months [T4], and six months [T5]). SI was assessed using the Columbia Suicide Severity Rating Scale (C-SSRS), and depressive symptoms were evaluated using the Montgomery–Åsberg Depression Rating Scale (MADRS). Furthermore, sociodemographic, clinical, and pharmacological data were collected. Results: Eighty patients diagnosed with TRD were enrolled. Suicidal ideation (C-SSRS items 1–5) decreased from 1.56 ± 1.65 at baseline to 0.78 ± 1.28 at T1 and 0.12 ± 0.52 at T5 (all p < 0.001). MADRS fell from 31.81 ± 7.94 to 23.62 ± 9.08 and 10.19 ± 7.33 at the same time points (all p < 0.001). By T1, 68.4% achieved an SI response on the C-SSRS. The MADRS response rate increased from 16.7% at T1 to an overall response of 62.5% at T5. Male sex predicted lower odds of early response on the C-SSRS (OR = 0.21, p = 0.031); no other baseline variable was significant as a predictor. Conclusions: Intranasal Esketamine has been shown to be effective in the rapid reduction and lysis of SI in patients with TRD. Male gender was found as a negative predictor of response, suggesting the importance of considering gender differences during treatment planning.

Background: Suicidal ideation (SI) represents a clinical challenge in patients with treat-ment-resistant depression (TRD), and the management of this condition would be as rap-id and effective as possible. Intranasal Esketamine has shown promise in patients with TRD due to its rapid onset of action on both SI and depressive symptoms. Since this med-ication has been recently approved, real-world data on its efficacy remains scarce, and lit-tle is known about which patients are most likely to benefit from this approach. Aims: This study aimed 1) to evaluate the efficacy of intranasal Esketamine on SI and depressive symptoms and 2) to find potential predictors of clinical response. Methods: Patients with TRD who received intranasal Esketamine were included in the study. Clinical evaluations and psychometric assessments were made at baseline (T0) and at five subsequent time points (one week [T1], one month [T2], two months [T3], three months [T4], and six months [T5]). SI was assessed using the Columbia Suicide Severity Rating Scale (C-SSRS), and depressive symptoms were evaluated using the Montgomery–Åsberg Depression Rating Scale (MADRS). Furthermore, socio-demographic, clinical, and pharmacological data were collected. Results: Eighty patients diagnosed with TRD were enrolled. Suicidal ideation (C-SSRS items 1–5) decreased from 1.56 ± 1.65 at baseline to 0.78 ± 1.28 at T1 and 0.12 ± 0.52 at T5 (all p < .001). MADRS fell from 31.81 ± 7.94 to 23.62 ± 9.08 and 10.19 ± 7.33 at the same time points (all p < .001). By T1, 68.4% achieved SI response on the C-SSRS. MADRS response rate increased from 16.7% at T1 to an overall response of 62.5% at T5. Male sex predicted lower odds of early response on the C-SSRS (OR = 0.21, p = .031); no other baseline variable was significant as a predictor. Conclusions: Intranasal Esketa-mine has been shown to be effective in the rapid reduction and lysis of SI in patients with TRD. Male gender was found as a negative predictor of response, suggesting the im-portance of considering gender differences during treatment planning.

Introduction: Major depressive disorder (MDD) is a leading cause of disability worldwide and contributes significantly to the global burden of disease. Recent data show an increasing prevalence of treatment-resistant depression (TRD). Patients with autism spectrum disorder (ASD) often exhibit MDD as a comorbidity and it is often resistant to conventional treatments. ASD determines emotional dysregulation and a reduced ability to understand mental states (mentalization). These features can lead to suicidal ideation and/or behavior. Intranasal esketamine may offer a novel therapeutic option for this population. Methods: This case series focuses on the clinical response to intranasal esketamine in patients with autism and TRD; esketamine is approved in Italy as an add-on therapy in TRD, so our case study is based on an in-label treatment. Three young patients (n = 3, F/M 2:1, age range 20–25 y) with light to moderate autism (Level 1 or 2) were treated. Esketamine was administered in augmentation with selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs) in accordance with EMA/AIFA guidelines. A structured follow-up protocol was set to monitor depressive symptoms, social cognition, and mentalization. Follow-up during treatment was maintained for six months, and psychometric evaluations were performed at six time points: baseline (T0), 1 week (T1), 1 month (T2), 2 months (T3), 3 months (T4), and 6 months (T5). Also, subjective quality of life was investigated before and after the observation period. Results: Despite differences in clinical profile, all patients showed good efficacy of esketamine in reducing depressive symptoms: two patients experienced clinical remission at T5 (MADRS < 10), one patient showed partial response (dMADRS = 43.24%). No major side effects were reported. Significant improvements were observed after the first week of treatment (P1: MADRS_T0 = 37, MADRS_T1 = 12; P2: MADRS_T0 = 32, MADRS_T1 = 21; P3: MADRS_T0 = 25, MADRS_T1 = 12). Depressive relapses occurred (e.g., P1, T3–T4), but they were not associated with hospitalizations and/or suicidal attempts. Suicidal ideation, when present, decreased by the end of the follow-up period. Lack of mentalization and in social cognition was noted, with just mild improvements during therapy. Subjective quality of life improved significantly for all patients (P1: 28% at T0, 73% at T5. P2: 25% at T0, 71% at T5. P3: 35% at T0, 80% at T5). Conclusions: Intranasal esketamine showed a favorable efficacy and safety in these three cases of TRD in comorbidity with ASD (at six months: total remission = 66.66%, partial remission = 33.33%, inefficacy = 0%, drop-out = 0, severe adverse events = 0). Besides improvements in depressive symptoms, esketamine was associated with a constant decrease in suicidal thoughts. A case series is unfit to form statistical conclusions; preliminary data warrant further investigation in randomized controlled studies to validate the therapeutic potential of esketamine in this population.

INTRODUCTION Major Depressive Disorder (MDD) is a leading cause of disability worldwide and contributes significantly to the global burden of disease. Recent data show an increasing prevalence of Treatment-Resistant Depression (TRD). Patients with Autism Spectrum Disorder (ASD) often exhibit MDD as a comorbidity and it is often resistant to conventional treatments. ASD determines emotional dysregulation and a reduced ability to understand mental states (mentalization). These features can lead to suicidal ideation and/or behaviour. Intranasal Esketamine, approved for TRD, may offer a novel therapeutic option for this population. METHODS Our study evaluates the clinical response to intranasal Esketamine in patients with autism and TRD. The sample was composed of three young patients (n=3, F/M 2:1, age range 20-25 y) with light to moderate autism (Level 1 or 2). Esketamine was administered in augmentation with Selective Serotonin Reuptake Inhibitors (SSRIs) or Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs). A structured follow-up protocol was set to monitor depressive symptoms, social cognition and mentalization. Follow-up during treatment was maintained for six months and psychometric evaluations were performed at six time points: baseline (T0), 1 week (T1), 1 month (T2), 2 months (T3), 3 months (T4) and 6 months (T5). Also, subjective quality of life was investigated before and after the observation period. RESULTS Despite differences in clinical profile, all patients showed good efficacy of Esketamine in reducing depressive symptoms: two patients experienced clinical remission (MADRS decrease > 50% from T0 to T5), while one patient showed partial remission (dMADRS=43.24%). No major side effects were reported. Significant improvements were observed after the first week of treatment (P1: MADRS_T0=37, MADRS_T1=12. P2: MADRS_T0=32, MADRS_T1=21. P3: MADRS_T0=25, MADRS_T1=12). Depressive relapses occurred (e.g. P1, T3-T4) but they were not associated with hospitalizations and/or suicidal attempts. Suicidal ideation, when present, decreased by the end of the follow-up period. Lack in mentalization and in social cognition were noted, with just mild improvements during therapy. Subjective quality of life improved significantly for all patients (P1: 28% at T0, 73% at T5. P2: 25% at T0, 71% at T5. P3: 35% at T0, 80% at T5). CONCLUSIONS Intranasal Esketamine showed a favourable efficacy and safety profile in these three cases of TRD in comorbidity with ASD (at six months: total remission=66.66%, partial remission=33.33%, inefficacy=0%, drop-out=0, severe adverse events=0). Besides improvements in depressive symptoms, Esketamine was associated with a constant decrease in suicidal thoughts. The small sample size doesn’t allow us to formalize statistical conclusions; preliminary data warrant further investigation in larger and randomized control studies to validate the therapeutic potential of Esketamine in this population.