Esketamine for Unipolar Major Depression With Psychotic Features: A Retrospective Chart Review and Comparison With Nonpsychotic Depression.

PURPOSES/BACKGROUND: The aims of the study were to assess subanesthetic esketamine as an antidepressant for major depressive disorder with psychotic features (PMDD) and to compare posttreatment symptoms among those with PMDD to a sample of nonpsychotic depression (major depressive disorder [MDD]). METHODS/PROCEDURES: This study is a retrospective chart review of patients with major depression and current psychotic symptoms, treated with a single parenteral 0.5-mg/kg dose of esketamine. Depression symptoms were assessed at baseline and 24-hour posttreatment with the Montgomery-Åsberg Depression Rating Scale. Individuals with PMDD were matched in a 1:2 ratio to nonpsychotic MDD patients from a randomized, noninferiority clinical trial of esketamine. FINDINGS/RESULTS: A total of 15 individuals with PMDD were included, which had higher baseline depression scores (PMDD = 40.9, MDD = 33.6, P = 0.004). A statistically significant change in depressive symptoms was found for the PMDD sample (ß = -16.20 [95% confidence interval, -23.30 to -9.10], P < 0.001), and no difference between PMDD and MDD groups was observed in the matched-sample analysis (ß = -2.2 [95% confidence interval, -9.32 to 4.58], P = 0.537). Treatment-induced dissociative symptoms were present for both groups, self-contained to within 2 hours after treatment, and no exacerbation of psychotic symptoms was found in clinical assessments. IMPLICATIONS/CONCLUSIONS: Results suggest a single 0.5-mg/kg dose of esketamine may benefit individuals with PMDD, and the symptom reduction may be comparable with esketamine's effects for MDD. Furthermore, esketamine may induce an antidepressant response in those with PMDD without complication of psychotic symptoms. Future research with controlled designs is warranted.

Clinical predictors of depressive symptom remission and response after racemic ketamine and esketamine infusion in treatment-resistant depression.

BACKGROUND: Major depressive disorder (MDD) is a leading cause of disability worldwide and most people do not achieve symptom remission. Treatment-resistant depression (TRD) is characterized by the failure of at least one adequate trial of a major class of antidepressant, with adequate time and dosage. We aimed to identify clinical predictors of depressive symptom remission and response 24 h and 7 days after racemic ketamine and esketamine infusions. METHODS: A randomized, double-blind, active-controlled, non-inferiority trial using ketamine and esketamine in TRD. Individuals diagnosed with MDD according to Diagnostic and Statistical Manual of Mental Disorders version IV and fulfilling TRD criteria were recruited from March 2017 to June 2018. Participants received a single subanesthetic dose of ketamine (0.5 mg/kg) or esketamine (0.25 mg/kg) for 40 min. Depressive symptoms were assessed using the Montgomery-Åsberg Depression Rating Scale (MADRS) and symptom remission was defined as a MADRS score ≤7 and response defined as ≥50% reduction in depressive symptom severity, 24 h and 7 days after the infusion. Clinical variables were selected based on previous clinical trials. Stepwise backward logistic regression was used, considering a confidence level of 95%. RESULTS: 61 subjects were included: 39 (63.9%) were females with a mean age of 47.2 ± 14.9. Higher number of therapeutic failures (Odds Ratio (OR) = 0.677; 95% confidence interval (CI): 0.47-0.97) and higher severity of illness (OR = 0.912; 95% CI: 0.83-0.99) were associated with fewer remissions of depressive symptoms 7 days after intervention, and with fewer response in 24 h (OR = 0.583; 95% CI: 0,40; 0,84 and OR = 0.909; 95% CI: 0,83; 0,99, respectively). CONCLUSION: Number of treatment failures and severity of illness were predictors of fewer remissions and responses of depressive symptoms in this TRD population. Study of predictors of remission may contribute to better selection patients that may benefit from receiving ketamine.

Neuropsychological effects of direct-acting antiviral treatment for Hepatitis C virus subjects: A systematic review.

Direct-acting antivirals (DAAs) have been approved in recent years to treat patients infected by the Hepatitis C virus (HCV). The DAAs treatment is well tolerated and increases sustained virological responses, but there is no consensus about the neuropsychological functioning related to the treatment. This systematic review aims to provide an overview of the recent findings exploring the cognitive effects of DAAs treatment in patients with HCV. After a systematic search on PubMed, Embase, Scopus and LILACS, studies that assessed neuropsychological data related to DAAs treatment were included. We found nine articles, considering the inclusion and exclusion criteria. Three other manuscripts were included after searching for the references listed in the previously mentioned articles. We observed methodological heterogeneity in terms of neuropsychological tests used, cognitive domain explored and the sample characteristic presented between the studies. Studies presented data from HCV subjects monoinfected with or without cirrhosis, advanced liver disease and post-transplant patients; and HCV subjects coinfected with human immunodeficiency virus (HIV). Most results from the 12 studies that explored the effect of DAAs treatment in HCV subjects' neurocognitive functioning demonstrated cognitive improvement following treatment. In general, HCV and HCV/HIV subjects improved processing speed, verbal fluency and verbal/visual episodic memory. The DAAs treatment is effective for neurocognitive functioning in HCV monoinfected and coinfected subjects, with or without advanced liver disease, since neuropsychological scores increased after treatment. Further studies, however, are needed to confirm these findings.

Intravenous arketamine for treatment-resistant depression: open-label pilot study.

We aimed to analyze the efficacy and safety of arketamine, the R(-)-enantiomer of ketamine, for treatment-resistant depression (TRD) in humans. Open-label pilot trial, seven subjects with TRD received a single intravenous infusion of arketamine (0.5 mg/kg); primary outcome was change in Montgomery-Åsberg Depression Rating Scale (MADRS) 24 h after. Mean MADRS dropped from 30.7 before infusion to 10.4 after one day, a mean difference of 20.3 points [CI 95% 13.6-27.0; p < 0.001]; dissociation was nearly absent. Arketamine might produce fast-onset and sustained antidepressant effects in humans with favorable safety profile, like previously reported with animals; further controlled-trials are needed.

Comparative study of impulsiveness and risk behaviors among infected individuals with hepatitis C virus and human T-cell lymphotropic virus type 1.

INTRODUCTION AND OBJECTIVES: Hepatitis C virus (HCV) and human T-cell lymphotropic virus type 1 (HTLV-1) infections have chronic courses. HCV is primarily transmitted via the hematogenous route, whereas HTLV-1 is primarily transmitted sexually, although it can also be transmitted by blood. Individuals chronically infected with either HTLV-1 or HCV can differ in terms of behavioral characteristics and personality traits. This study compared the occurrence of risk behaviors and impulsivity aspects between HCV and HTLV-1 carriers. MATERIALS AND METHODS: Observational, comparative and cross-sectional study that involved a sample of outpatients who had HCV or HLTV-1, by way of a sociodemographic and behavioral questionnaire and the Barratt Impulsiveness Scale - BIS-11. 143 individuals with HCV and 113 individuals with HTLV-1 were evaluated. RESULTS: There was a difference with regards to gender among patients, with mostly males affected in the HCV group. Risk behaviors commonly mediated by impulsiveness were significantly more frequent in the HCV group. Similarly, overall impulsiveness and domain nonplanning were higher in the HCV group. Multivariate analysis showed that increased age, male gender, higher nonplanning scores and HCV infection were independent factors for the occurrence of risk behaviors. Both groups presented high rates of other sexually transmitted diseases and a low rate of condom use in sexual relations. CONCLUSIONS: This study confirms the higher rate of risk behaviors and the levels of impulsiveness commonly observed in patients with HCV, along with comparisons to patients with HTLV-1.

The Portuguese Version of the Immunosuppressant Therapy Adherence Scale (ITAS) among Liver Transplant Recipient Patients: Translation and Psychometric Properties.

INTRODUCTION AND AIM: Transplant recipients are chronically ill patients who rely on medical treatment throughout life to achieve positive results. Despite that, medication nonadherence after liver transplantation is extremely common. The self-report, one of several methods for measuring adherence, is easy to apply and low cost. Thus, this study aims to translate and validate the Immunosuppressant Therapy Adherence Instrument (ITAS) in Brazilian Portuguese for liver transplant recipients. MATERIAL AND METHODS: A total of 139 liver transplant recipients were selected from a general hospital, who were assessed by using the Portuguese version of ITAS. The scale was translated based on the model proposed by Wild, et al. and its psychometric properties were assessed. RESULTS: The average Cronbach's α coefficient was 0.830. ITAS and Basel Assessment of Adherence with Immunosuppressive Medications Scale (BAASIS) presented significant correlation, with a Spearman's ρ coefficient = 0.300 (S = 309,580; p < 0.001). The area under the receiver operating characteristics (ROC) curve was 0.638 (95% CI: 0.557 - 0.715). Factor analysis results indicated that the carelessness factor model was the optimal model, and the factor "feeling worse" was the lowest. CONCLUSION: The Portuguese version of ITAS has adequate psychometric properties to measure adherence to immunosuppressant therapy.

Types of Trauma, Posttraumatic Stress Disorder, and Academic Performance in a Population of University Students.

The aim of this work was to investigate the association between traumatic experiences and posttraumatic stress disorder (PTSD) with the academic performance of university students. This is a one-phase study that included 2213 students, enrolled at one of seven college institutions in their first or final semesters in all programs, who filled out the self-response questionnaires. From this student population, 14% presented with PTSD, with 13.3% in their first semester and 14.9% in their final semester. The students who presented lower academic results (low scoring) had a higher prevalence of PTSD in both the first and final semesters. Nonsexual violence was related with low scoring in the first-semester students. Thus, we conclude that students in the PTSD group present worse academic performance. These results indicate a need to pay attention to students who have been through traumatic experiences and gone on to develop PTSD, to ensure their undergraduate success and enable their future performance as professionals.

The fatigue impact scale for daily use in patients with hepatitis B virus and hepatitis C virus chronic infections.

INTRODUCTION: Fatigue is an important clinical finding in the hepatitis virus chronic infection. However, the absence of scales to measure fatigue, translated and validated for Brazilian Portuguese, prevents access to information essential in clarifying specific clinical conditions in this population. AIM: The aim of this study was to determine the psychometric properties of the fatigue impact scale for daily use (D-FIS), in Brazilian Portuguese, for patients with the hepatitis C virus (HCV) and hepatitis B virus (HBV) chronic infection. MATERIAL AND METHODS: In this cross-sectional study, the authors evaluated the D-FIS in 101 outpatients, followed at the reference hospital. The Mini International Neuropsychiatric Interview Brazilian (MINI PLUS) was used to identify psychiatric disorders, and the Short Form Health Survey 36-item (SF-36) to evaluate the self-reported quality of life. We also examined the impact of fatigue on the quality of life of this group of patients. RESULTS: Relevant psychometric D-FIS results were: floor effect proved to be 1%; skewness was 0.46; item homogeneity was 0.59 and SEM (SD = 8.51) was 2.4. The Cronbach's alpha was 0.920 and item total correlation yielded coefficients ranging from 0.65 (item 1) to 0.85 (item 3). In a linear regression model, fatigue and depression influenced the self-reported quality of life. CONCLUSION: This study presents that the fatigue scale for daily use in Brazilian Portuguese can be considered a useful tool to verify the presence of fatigue in patients with the hepatitis viruses B and C.

Religiosity and Impulsivity in Mental Health: Is There a Relationship?

Our aim is to evaluate the relationship between religiosity and impulsivity in patients with mental illness who had attempted suicide and in healthy individuals. This is a cross-sectional study that included 61 healthy individuals and 93 patients. The instruments used were a sociodemographic data questionnaire, the Mini International Neuropsychiatric Interview, the Barratt Impulsiveness Scale, and the Duke University Religion Index. The healthy individuals presented higher scores in the religiosity domains (organizational, p = 0.028; non-organizational, p = 0.000; intrinsic, p = 0.000). The patients presented higher scores in the impulsivity dimensions (attentional, p = 0.000; motor, p = 0.000; absence of planning, p = 0.000). In the patient group, intrinsic religiosity had a significant inverse relationship with total impulsivity (p = 0.023), attentional (p = 0.010), and absence of planning (p = 0.007), even after controlling for sociodemographic variables. Healthy individuals were more religious and less impulsive than patients. The relationship between religiosity, impulsiveness, and mental illness could be bidirectional; that is, just as mental illness might impair religious involvement, religiosity could diminish the expression of mental illness and impulsive behaviors.

MicroRNAs as Diagnostic Biomarkers and Predictors of Antidepressant Response in Major Depressive Disorder: A Systematic Review.

Despite the hardships of major depressive disorder (MDD), biomarkers for the diagnosis and pharmacological management of this condition are lacking. MicroRNAs are epigenetic mechanisms that could provide promising MDD biomarkers. Our aim was to summarize the findings and provide validation for the selection and use of specific microRNAs as biomarkers in the diagnosis and treatment of MDD. A systematic review was conducted using the PubMed/Medline, Cochrane, PsycINFO, Embase, and LILACS databases from March 2022 to November 2023, with clusters of terms based on "microRNA" and "antidepressant". Studies involving human subjects, animal models, and cell cultures were included, whereas those that evaluated herbal medicines, non-pharmacological therapies, or epigenetic mechanisms other than miRNA were excluded. The review revealed differences in the expression of various microRNAs when considering the time of assessment (before or after antidepressant treatment) and the population studied. However, due to the heterogeneity of the microRNAs investigated, the limited size of the samples, and the wide variety of antidepressants used, few conclusions could be made. Despite the observed heterogeneity, the following microRNAs were determined to be important factors in MDD and the antidepressant response: mir-1202, mir-135, mir-124, and mir-16. The findings indicate the potential for the use of microRNAs as biomarkers for the diagnosis and treatment of MDD; however, more homogeneous studies are needed.

Ketamine for catatonia: A novel treatment for an old clinical challenge? A systematic review of the evidence.

INTRODUCTION: Catatonia, documented since the 19th century, remains a significant challenge in terms of recognition and treatment. Over the last two decades, ketamine has brought new perspectives to psychiatry, sparking widespread interest. Concurrently, catatonia has attracted heightened scientific attention. Preliminary evidence suggests the therapeutic potential of ketamine for catatonia. METHODS: We systematically searched Medline/PubMed, Embase, PsycINFO, Lilacs, and Cochrane Library databases, as well as Google Scholar, for studies with ketamine or its enantiomers as intervention for catatonia, with no restrictions to underlying diagnosis, date, language, or study design. RESULTS: Twenty articles were included, encompassing a total of 25 catatonic patients receiving ketamine or esketamine. Predominantly female (61.9 %), with a mean age of 44.4 years, patients mostly exhibited manifestations compatible with the retarded subtype of catatonia. Mood disorders were the most prevalent underlying diagnoses. Ketamine was primarily administered intravenously over a 40-minute period and in multiple-dosing schemes. Mean response and remission rates of catatonic manifestations for the whole sample were 80 % and 44 %, respectively, with no reports of worsening catatonic features or psychotic symptoms. Only one patient discontinued treatment due to intolerable dissociative effects. CONCLUSION: Challenging the conventional contraindication of ketamine in psychotic disorders, current evidence highlights its potential efficacy, particularly in treating catatonia. Pending further research, we advocate reevaluating this contraindication, as it may offer a promising therapeutic option, especially for challenging cases. Preliminary evidence suggests potentially greater benefits for catatonic patients with underlying mood disorders compared to primary psychotic disorders.

Esketamine Augmentation in Treatment-Resistant Obsessive-Compulsive Disorder: A Retrospective Chart Review.

OBJECTIVE: Converging evidence supports the role of the glutamate, an excitatory amino acid neurotransmitter, in the pathophysiology of obsessive-compulsive disorder (OCD). Ketamine and esketamine, both noncompetitive N -methyl- d -aspartate antagonists, have emerged as a promising medication for this psychiatric disorder, given its possible efficacy with faster onset and good tolerability. The purpose of this retrospective chart review is to evaluate whether unbiased clinical documentation supports formal clinical trials of esketamine for an OCD indication. METHODS: A retrospective chart review of patients with treatment-resistant OCD receiving a single dose of esketamine (0.5mg/kg) added to standard therapy was conducted. The Yale-Brown Obsessive-Compulsive Scale and the Montgomery-Åsberg Depression Rating Scale were used to evaluate OCD and depressive symptoms respectively at baseline, 24 hours, and 7 days after esketamine administration. Descriptive statistics were used to analyze the data. RESULTS: Eight subjects were identified in this retrospective chart review: esketamine was administered subcutaneously in 7 and intravenously in 1. One week after infusion, 25% of the sample met criteria for treatment response and 50% for partial response. Major depressive disorder was a comorbid diagnosis in 75% of the sample and 2 of these subjects showed a positive antidepressant response. CONCLUSIONS: Our findings provide preliminary evidence that esketamine may reduce obsessive-compulsive symptoms in a subset of treatment-resistant OCD patients.

Systemic lupus, folie a trois and homicide.

Folie a trois is a syndrome characterized by the transfer of delusional ideas from one person to two other persons. This condition rarely ends in the murder of any involved and we are unaware of where the primary case had the diagnosis of acute psychosis in systemic lupus erythematosus (SLE). We present a case report of folie a trois resulting in murder, secondary to acute psychosis in SLE.

Impact of sustained virologic response on quality of life in chronic HVC carriers.

INTRODUCTION: It is known that patients with chronic hepatitis C have a lower health-related quality of life (HRQOL) than the general population and evidence suggests that the hepatitis C virus (HCV) could exert direct neuropathic action on HRQOL. From this perspective, the virus clearance should be accompanied by improvement in HRQOL. Thus, we sought to review systematically the evidence in the literature and perform a meta-analysis of HRQOL changes caused by sustained virologic response (SVR). MATERIAL AND METHODS: The PubMed was searched using the keywords Hepatitis C, Quality of Life and Therapy. The reviewers came to a consensus on articles that were selected to full reading and those that should be included in the study and a meta-analysis was performed of mean change difference between responders and non-responders. RESULTS: Eleven studies were included in the systematic review and four in the metaanalysis. Of these, nine studies showed more favorable outcome for responders, and they had a better outcome even in studies that evaluated only cirrhotic patients, previous non-responders, relapsers, patients in first treatment and patients unaware of treatment response. Moreover, the meta-analysis showed that the general health and vitality domains had statistically significant mean change difference between responders and non-responders, presenting a summary effect of 6.3 (CI 95% 2.5-10.0) and 7.8 (CI 95% 3.4- 12.1) respectively. CONCLUSION: There is evidence indicating that SVR is accompanied by an improvement in HRQOL and patients reaching SVR have clinically relevant improvement in domains of general health and vitality.

Posttraumatic stress disorder in demobilized ex-combatants from illegal armed groups in Colombia: Cross-sectional study.

OBJECTIVE: The objective of this study was to describe the psychological and quality of life outcomes in demobilized Colombian ex-combatants. METHOD: A cross-sectional study was conducted on 58 ex-combatants from the Colombian government's reintegration program. Posttraumatic stress disorder (PTSD) was measured by the Mini-International Neuropsychiatric Interview. We applied the Beck-II Depression Inventory, Resilience Scale, Everyday Discrimination Scale, and World Health Organization Quality of Life-Short Version (WHOQOL-BREF) for measuring symptoms of depression, resilience, discrimination, and quality of life, respectively. RESULTS: The prevalence of PTSD was 63,8%, principally on ex-combatants with ≤10 years in the reinstatement program. Females with primary/elementary school, extremely low social status, unipersonal family type, family income <1 minimal wage, and symptoms of depression showed a higher prevalence ratio (>1.30). The mean scores of depression symptoms, resilience, and quality of life were systematically poorer in the group with PTSD. Significant differences were found Resilience scale domains Personal Competence (p = .043) and Acceptance of Self and Life (p = .012), WHOQOL-BREF Psychological (p = .029) and Environment domains (p = .015). CONCLUSIONS: Colombian ex-combatants with PTSD attending a reinstatement program presented a higher frequency of depression symptoms, lower quality of life, and lower resilience than those without PTSD. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Psychopathological symptoms in parents and siblings of people on the autism spectrum: A systematic review and meta-analysis.

Parents and siblings of children on the autism spectrum experience significant distress, and for this reason, it is essential to understand the most prevalent psychopathological symptoms among this population. This work aims to establish the prevalence of psychopathological symptoms in parents and siblings of individuals on the autism spectrum, following the Preferred Reporting Items for Systematic Review and Meta-Analyses Protocols (PRISMA-P) criteria. Searches were carried out using the PubMed/Medline, Embase, PsycINFO, SciELO, and Biblioteca Virtual em Saúde (BVS) databases. Twenty-three articles were included in this review. Depressive symptoms were the most frequently reported conditions, with a higher prevalence in mothers of children on the autism spectrum. In the meta-analysis, mothers of children on the autism spectrum scored higher by 0.42 standard deviations on the symptom scales (SMD 0.42; CI 0.25-0.59), with low statistical heterogeneity (I2 0%, p = 0.5) when compared with mothers of children with atypical development. The psychopathological symptoms of relatives should be investigated as part of the follow-up procedures for the child on the autism spectrum to facilitate their treatment.

Arketamine for bipolar depression: Open-label, dose-escalation, pilot study.

There are significantly fewer options for the treatment of bipolar depression than major depressive disorder, with an urgent need for alternative therapies. In this pilot study, we treated six subjects with bipolar disorder types I and II (according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria) who had been in a current depressive episode for at least four weeks. Four subjects were female (66.66%), and the mean age was 45.33 (±12.32). Subjects received adjunct treatment with two arketamine intravenous infusions one week apart-0.5 mg/kg first and then 1 mg/kg. The mean baseline Montgomery-Åsberg Depression Rating Scale (MADRS) total score was 36.66, which decreased to 27.83 24h after the first infusion of 0.5 mg/kg of arketamine (p = 0.036). In respect of the 1 mg/kg dose, the mean MADRS total score before the second infusion was 32.0, which dropped to 17.66 after 24h (p < 0.001). Arketamine appears to have rapid-acting antidepressant properties, consistent with previous animal studies on major depression. All individuals tolerated both doses, exhibiting nearly absent dissociation, and no manic symptoms. To the best of our knowledge, this pilot trial is the first to test the feasibility and safety of the (R)-enantiomer of ketamine (arketamine) for bipolar depression.

Brain-derived neurotrophic factor serum levels following ketamine and esketamine intervention for treatment-resistant depression: secondary analysis from a randomized trial.

OBJECTIVES: Evidence suggests that ketamine's influence on brain-derived neurotrophic factor (BDNF) might be involved in its mechanism of rapid antidepressant action. We aimed to evaluate the differential impact of ketamine and esketamine on serum BDNF levels and its association with response patterns in treatment-resistant depression (TRD). METHODS: Participants (n = 53) are from a randomized, double-blind clinical trial comparing the efficacy of single-dose ketamine (0.5mg/kg, n = 27) and esketamine (0.25mg/kg, n = 26) in TRD. Depression severity was assessed before and 24 hours, 72 hours, and 7 days after the intervention, using the Montgomery-Åsberg Depression Rating Scale (MADRS). Blood samples were collected before infusion, 24 hours, and 7 days afterwards. RESULTS: There were no significant changes in BDNF levels at post-infusion evaluation points, and no difference in BDNF levels comparing ketamine and esketamine. Both drugs exhibited similar therapeutic effect. There was no association between BDNF levels and response to treatment or severity of depressive symptoms. CONCLUSION: There was no significant treatment impact on BDNF serum levels - neither with ketamine nor esketamine - despite therapeutic response. These results suggest that ketamine or esketamine intervention for TRD has no impact on BDNF levels measured at 24 hours and 7 days after the infusion.

Does the intensity of dissociation predict antidepressant effects 24 hours after infusion of racemic ketamine and esketamine in treatment-resistant depression? A secondary analysis from a randomized controlled trial.

BACKGROUND: Ketamine and esketamine have both shown significant antidepressant effects in treatment-resistant depression (TRD), and conflicting evidence suggests that induced dissociation by these drugs can be a clinical predictor of esketamine/ketamine's efficacy. METHODS: This study is a secondary analysis from a bi-center, randomized, controlled trial. Participants were randomly assigned 1:1 to receive an IV infusion of esketamine (.25 mg/kg) or racemic ketamine (.50 mg/kg) over 40 minutes. Dissociative symptoms were assessed using the Clinician-Administered Dissociative State Scale (CADSS) 40 minutes following the beginning of the infusion. The variation in depression scores was measured with the Montgomery-Asberg Depression Rating Scale (MADRS), which was administered before the intervention as a baseline measure and 24 hrs, 72 hrs, and 7 days following infusion. RESULTS: Sixty-one patients were included in the analysis. Examining CADSS scores of 15 or below, for every 1-point increment in the CADSS score, there was a mean change of -0.5 (SD = 0.25; p-value 0.04) of predicted MADRS score from baseline to 24 hrs. The results for 72 hrs and 7 days following infusion were not significant. Limitations: This study was not designed to assess the relationship between ketamine or esketamine-induced dissociation and antidepressant effects as the main outcome, therefore confounding variables for this relationship were not controlled. CONCLUSION: We suggest a positive relationship between dissociation intensity, measured by CADSS, and antidepressant effect 24 hours after ketamine and esketamine infusion for a CADSS score of up to 15 points.

Arketamine as adjunctive therapy for treatment-resistant depression: A placebo-controlled pilot study.

BACKGROUND: Racemic ketamine is a mixture of (R)-ketamine (arketamine) and (S)-ketamine (esketamine), with the latter regarded as the main isomer for antidepressant effects. However, preclinical data and one open-label human trial suggest arketamine might exert a more potent and longer-lasting antidepressant effect with fewer side effects. We aimed to explore the feasibility of a randomized controlled trial of arketamine for treatment-resistant depression (TRD) and to assess its efficacy and safety compared to placebo. METHODS: This is a, randomized, double-blind, crossover, pilot trial (n = 10). All participants received saline and arketamine (0.5 mg/kg) with a one-week interval. Treatment effects were analyzed with a linear mixed effects (LME) model. RESULTS: Our analysis suggested the presence of a carryover effect, so the main efficacy analysis was limited to the first week, which demonstrated a main effect of time (p = 0.038) but not for treatment (p = 0.40) or their interaction (p = 0.95). This indicates that depression improved over time, but without significant difference between arketamine and placebo. Analyzing the two weeks together, findings were the same. Dissociation and other adverse events were minimal. LIMITATIONS: This was a pilot study with a small sample and underpowered. CONCLUSIONS: Arketamine was not superior to placebo for TRD but demonstrated to be extremely safe. Our findings reinforce the importance of continuing studies with this drug, with better powered clinical trials, perhaps considering a parallel design with higher or flexible doses and repeated administrations.