Double-blind, placebo-controlled, proof-of-concept trial of a kappa-selective opioid receptor antagonist augmentation in treatment-resistant depression.

BACKGROUND: Kappa-opioid antagonism may possess antidepressant properties. We assessed, in a proof-of-concept pilot trial among patients with major depressive disorder with inadequate response to antidepressants, the efficacy of adjunctive CERC-501 (formerly LY2456302), a kappaselective opioid receptor antagonist. METHODS: In a Sequential Parallel Comparison Design study, patients were pre-randomized to: a) 10 mg/d of CERC-501 for 6 days, b) 20 mg/d of CERC-501 for 6 days, c) placebo for 3 days followed by 10 mg/d of CERC- 501 for 3 days, d) placebo for 3 days followed by 20 mg/d of CERC-501 for 3 days, or e) placebo for 6 days. RESULTS: The study was terminated early by the National Institute of Mental Health due to slow enrollment (N = 8). The weighted mean difference of changes (drug vs placebo) in the 6-item Hamilton Depression Rating Scale (HAMD-6) (primary outcome measure) (1.28), Montgomery-Åsberg Depression Rating Scale (MADRS) (2.33), Perceived Stress Scale (1.01), Symptoms of Depression Questionnaire (9.17), Positive Affect Scale (PAS) (6.39), Symptom Questionnaire (SQ) Depression scale (2.94), SQ Anger- Hostility scale (1.67), and Patient-Reported Outcomes Measurement Information System Satisfaction with Participation in Discretionary Social Activities (4.67) scores were all numerically but not statistically greater for CERC-501 than for placebo. CONCLUSIONS: Although the small sample size limits the ability to draw conclusions, results suggest that CERC-501 may have antidepressant effects. Additional studies are necessary to further explore these effects of CERC-501.

Body Mass Index as a Moderator of Treatment Response to Ketamine for Major Depressive Disorder.

PURPOSE/BACKGROUND: Major depressive disorder (MDD) and obesity commonly co-occur. We sought to assess the impact of body mass index (BMI) on the acute antidepressant effects of ketamine in patients with treatment-resistant depression. METHODS/PROCEDURES: Post hoc analyses were conducted from a multisite, randomized, double-blind, placebo-controlled trial designed to assess the rapid-onset effects of intravenous ketamine. Patients (n = 99) were randomized to a single dose administration of ketamine 0.1 mg/kg (n = 18), ketamine 0.2 mg/kg (n = 20), ketamine 0.5 mg/kg (n = 22), ketamine 1.0 mg/kg (n = 20), or active placebo, midazolam 0.045 mg/kg (n = 19). Patients were stratified for BMI. For patients randomized to ketamine (n = 80), BMI was assessed as a continuous variable and also categorically (obese, overweight, not obese/overweight [reference]). The primary outcome measure was the change on the 6-item Hamilton Depression Rating Scale 24 hours after treatment. Outcomes at day 3 were also assessed. FINDINGS/RESULTS: The 6-item Hamilton Depression Rating Scale change scores at 24 hours were inversely associated with BMI (-0.28 ± 0.12, P = 0.02). With BMI operationalized categorically, both obese (-4.15 ± 1.41, P = 0.004) and overweight (-1.99 ± 1.14, P = 0.08) categories were inversely related to the 6-item Hamilton Depression Rating Scale change score at 24 hours, statistically significant for the obese category, as compared with the reference group. Similar but weaker findings were observed at 72 hours after infusion. IMPLICATIONS/CONCLUSIONS: Higher BMI and obesity were associated with a more robust acute antidepressant response to ketamine. This may have clinical relevance for a great number of patients who have both MDD and obesity. CLINICAL TRIAL REGISTRATION: NCT01920555.

Correction: Double-blind, placebo-controlled, dose-ranging trial of intravenous ketamine as adjunctive therapy in treatment-resistant depression (TRD).

Supplementary Figure 1 and Supplementary Tables 1-4 have been re-uploaded so as to reflect the versions supplied during proofs stage. The publisher apologizes for the error in versioning. The HTML version of the paper has been updated.

Double-blind, placebo-controlled, dose-ranging trial of intravenous ketamine as adjunctive therapy in treatment-resistant depression (TRD).

Numerous placebo-controlled studies have demonstrated the ability of ketamine, an NMDA receptor antagonist, to induce rapid (within hours), transient antidepressant effects when administered intravenously (IV) at subanesthetic doses (0.5 mg/kg over 40 min). However, the optimal antidepressant dose remains unknown. We aimed to compare to active placebo the rapid acting antidepressant properties of a broad range of subanesthetic doses of IV ketamine among outpatients with treatment-resistant depression (TRD). A range of IV ketamine doses were compared to active placebo in the treatment of adult TRD over a 3-day period following a single infusion over 40 min. This was an outpatient study conducted across six US academic sites. Outpatients were 18-70 years old with TRD, defined as failure to achieve a satisfactory response (e.g., less than 50% improvement of depression symptoms) to at least two adequate treatment courses during the current depressive episode. Following a washout period, 99 eligible subjects were randomly assigned to one of the five arms in a 1:1:1:1:1 fashion: a single intravenous dose of ketamine 0.1 mg/kg (n = 18), a single dose of ketamine 0.2 mg/kg (n = 20), a single dose of ketamine 0.5 mg/kg (n = 22), a single dose of ketamine 1.0 mg/kg (n = 20), and a single dose of midazolam 0.045 mg/kg (active placebo) (n = 19). The study assessments (HAM-D-6, MADRS, SDQ, PAS, CGI-S, and CGI-I) were performed at days 0, 1, 3 (endpoint), 5, 7, 14, and 30 to assess the safety and efficacy. The overall group × time interaction effect was significant for the primary outcome measure, the HAM-D-6. In post hoc pairwise comparisons controlling for multiple comparisons, standard dose (0.5 mg/kg) and high dose (1 mg/kg) of intravenous ketamine were superior to active placebo; a low dose (0.1 mg/kg) was significant only prior to adjustment (p = 0.02, p-adj = 0.14, d = -0.82 at day 1). Most of the interaction effect was due to differences at day 1, with no significant adjusted pairwise differences at day 3. This pattern generally held for secondary outcomes. The infusions of ketamine were relatively well tolerated compared to active placebo, except for greater dissociative symptoms and transient blood pressure elevations with the higher doses. Our results suggest that there is evidence for the efficacy of the 0.5 mg/kg and 1.0 mg/kg subanesthetic doses of IV ketamine and no clear or consistent evidence for clinically meaningful efficacy of lower doses of IV ketamine. Trial Registration: NCT01920555.

Efficacy and Tolerability of Adjunctive Intravenous Sodium Nitroprusside Treatment for Outpatients With Schizophrenia: A Randomized Clinical Trial.

Importance: Antipsychotic medications for the treatment of schizophrenia have limitations, and new treatments are needed. A prior pilot investigation suggested that adjunctive sodium nitroprusside (SNP) administered intravenously had rapid efficacy in the treatment of patients with schizophrenia. Objective: To determine the efficacy and tolerability of intravenous SNP infused at a rate of 0.5 µg/kg/min for 4 hours in patients with schizophrenia with some degree of treatment resistance. Design, Setting, and Participants: Multicenter, randomized, double-blind acute treatment study using a sequential parallel comparison design conducted in two 2-week phases at 4 academic medical centers beginning May 20, 2015, and ending March 31, 2017. Participants were adults 18 to 65 years of age with a diagnosis of schizophrenia as confirmed by the Structured Clinical Interview for DSM-IV, taking antipsychotic medication for at least 8 weeks, and had at least 1 failed trial of an antipsychotic medication within the past year. A total of 90 participants consented, 60 participants enrolled, and 52 participants were included in the analyses. A modified intent-to-treat analysis was used. Interventions: Participants were randomized in a 1:1:1 ratio to 1 of 3 treatment sequences: SNP and SNP, placebo and SNP, and placebo and placebo. The SNP and SNP group received SNP in phase 1 and SNP in phase 2 for the purpose of blinding, but the data from phase 2 were not included in the results. The placebo and SNP group received placebo in phase 1 and SNP in phase 2. If there was no response to placebo in phase 1, data from phase 2 were included in the analyses. The placebo and placebo group received placebo in both phases; if there was no response to placebo in phase 1, data from phase 2 were included in the analyses. Main Outcomes and Measures: Effectiveness of SNP compared with placebo in improving Positive and Negative Syndrome Scale (PANSS) total, positive, and negative scores across each 2-week phase. Results: Fifty-two participants (12 women and 40 men) were included in the study. In the SNP and SNP group, the mean (SD) age was 47.1 (10.5) years. In the placebo and SNP group, the mean (SD) age was 45.9 (12.3) years. In the placebo and placebo group, the mean (SD) age was 40.4 (11.0) years. There were no significant differences between the SNP and placebo groups at baseline or in change from baseline for PANSS-total (weighted ß = -1.04; z = -0.59; P = .57), PANSS-positive (weighted ß = -0.62; z = -0.93; P = .35), or PANSS-negative (weighted ß = -0.12; z = -0.19; P = .85) scores. No significant differences in safety or tolerability measures were identified. Conclusions and Relevance: Although intravenous SNP is well tolerated, it was not an efficacious adjunctive treatment of positive or negative symptoms of psychosis among outpatients with schizophrenia with prior history of treatment resistance. Trial Registration: ClinicalTrials.gov identifier: NCT02164981.

Sex differences in response to ketamine as a rapidly acting intervention for treatment resistant depression.

BACKGROUND: While ketamine has been increasingly studied for treatment resistant depression (TRD), the impact of sex differences on treatment outcomes has not been well studied. The objective was to ascertain whether there were differences in response to a single administration of ketamine for TRD between men and women, and between pre- and post-menopausal women. METHODS: A randomized, double-blind, placebo-controlled trial (N = 99; N = 50 male; N = 49 female) was conducted to investigate the efficacy of intravenous ketamine versus active placebo as augmentation of antidepressant therapy for TRD. Patients were assigned to one of five arms; one-time administration of ketamine of varying doses (i.e., 0.1, 0.2, 0.5, and 1.0 mg/kg), and one group receiving active placebo (intravenous midazolam). A priori-planned analyses were conducted to compare responses between women and men, as well pre-vs. postmenopausal women. RESULTS: Analyses demonstrated no significant differences between women and men in terms of treatment response (F(1,80) = 0.06, p = 0.80). There were no significant differences in the frequency of adverse effects (AEs) reported by those assigned to ketamine treatment groups (p > 0.21 for all AEs reported more than once), although women reported more headaches (12% vs. 6%, p = 0.30) and nausea (10% vs. 6%, p = 0.47). In comparing pre-vs. postmenopausal women, no differences in efficacy were observed (F(1,76) = 0.36, p = 0.55). CONCLUSIONS: Results do not support differential efficacy or tolerability of ketamine for the treatment of TRD between women and men, nor based on menopause status among women. However, larger trials with these a priori aims are needed to confirm these results.