Efficacy and safety of a 4-week course of repeated subcutaneous ketamine injections for treatment-resistant depression (KADS study): randomised double-blind active-controlled trial

BACKGROUND

Prior trials suggest that intravenous racemic ketamine is a highly effective for treatment-resistant depression (TRD), but phase 3 trials of racemic ketamine are needed.

AIMS

To assess the acute efficacy and safety of a 4-week course of subcutaneous racemic ketamine in participants with TRD. Trial registration: ACTRN12616001096448 at www.anzctr.org.au.

METHOD

This phase 3, double-blind, randomised, active-controlled multicentre trial was conducted at seven mood disorders centres in Australia and New Zealand. Participants received twice-weekly subcutaneous racemic ketamine or midazolam for 4 weeks. Initially, the trial tested fixed-dose ketamine 0.5 mg/kg versus midazolam 0.025 mg/kg (cohort 1). Dosing was revised, after a Data Safety Monitoring Board recommendation, to flexible-dose ketamine 0.5-0.9 mg/kg or midazolam 0.025-0.045 mg/kg, with response-guided dosing increments (cohort 2). The primary outcome was remission (Montgomery-Åsberg Rating Scale for Depression score ≤10) at the end of week 4.

RESULTS

The final analysis (those who received at least one treatment) comprised 68 in cohort 1 (fixed-dose), 106 in cohort 2 (flexible-dose). Ketamine was more efficacious than midazolam in cohort 2 (remission rate 19.6% v. 2.0%; OR = 12.1, 95% CI 2.1-69.2, P = 0.005), but not different in cohort 1 (remission rate 6.3% v. 8.8%; OR = 1.3, 95% CI 0.2-8.2, P = 0.76). Ketamine was well tolerated. Acute adverse effects (psychotomimetic, blood pressure increases) resolved within 2 h.

CONCLUSIONS

Adequately dosed subcutaneous racemic ketamine was efficacious and safe in treating TRD over a 4-week treatment period. The subcutaneous route is practical and feasible.

Adjunctive Cariprazine for the Treatment of Patients With Major Depressive Disorder: A Randomized, Double-Blind, Placebo-Controlled Phase 3 Study

OBJECTIVE

The purpose of this study was to investigate the efficacy of cariprazine, a dopamine D₃-preferring D₃/D₂ and serotonin 5-HT_1A receptor partial agonist, as adjunctive therapy for patients with major depressive disorder and nonresponse to at least one antidepressant monotherapy.

METHODS

In this double-blind placebo-controlled study, adults with major depressive disorder and inadequate response to antidepressants alone were randomized in a 1:1:1 ratio to placebo, cariprazine at 1.5 mg/day, or cariprazine at 3.0 mg/day. The primary outcome was change from baseline to week 6 in total score on the Montgomery-Åsberg Depression Rating Scale (MADRS). Least-squares mean differences were estimated in the modified intent-to-treat (mITT) population using a mixed-effects model for repeated measures with adjustment for multiple comparisons.

RESULTS

The mITT population comprised 751 patients (placebo: N=249; cariprazine 1.5 mg/day: N=250; cariprazine 3.0 mg/day: N=252). At week 6, the mean reduction from baseline in MADRS total score was significantly greater with cariprazine 1.5 mg/day than with placebo (-14.1 vs. -11.5) but not with cariprazine 3.0 mg/day (-13.1). Significant differences between the cariprazine 1.5 mg/day and placebo groups were also observed at weeks 2 and 4. Meeting the MADRS response criteria was significantly more likely among patients receiving cariprazine 1.5 mg/day than placebo (44.0% vs. 34.9%); remission rates were not significantly different among groups. Common treatment-emergent adverse events (≥5% in either cariprazine group and twice the placebo rate) were akathisia and nausea.

CONCLUSIONS

Adjunctive cariprazine at 1.5 mg/day demonstrated efficacy in reducing depressive symptoms in adults with major depressive disorder and inadequate response to antidepressants alone. Cariprazine was generally well tolerated, with a safety profile that was consistent with previous findings.

Pharmacological properties of cannabidiol in the treatment of psychiatric disorders: a critical overview

Cannabidiol (CBD) represents a new promising drug due to a wide spectrum of pharmacological actions. In order to relate CBD clinical efficacy to its pharmacological mechanisms of action, we performed a bibliographic search on PUBMED about all clinical studies investigating the use of CBD as a treatment of psychiatric symptoms. Findings to date suggest that (a) CBD may exert antipsychotic effects in schizophrenia mainly through facilitation of endocannabinoid signalling and cannabinoid receptor type 1 antagonism; (b) CBD administration may exhibit acute anxiolytic effects in patients with generalised social anxiety disorder through modification of cerebral blood flow in specific brain sites and serotonin 1A receptor agonism; (c) CBD may reduce withdrawal symptoms and cannabis/tobacco dependence through modulation of endocannabinoid, serotoninergic and glutamatergic systems; (d) the preclinical pro-cognitive effects of CBD still lack significant results in psychiatric disorders. In conclusion, current evidences suggest that CBD has the ability to reduce psychotic, anxiety and withdrawal symptoms by means of several hypothesised pharmacological properties. However, further studies should include larger randomised controlled samples and investigate the impact of CBD on biological measures in order to correlate CBD's clinical effects to potential modifications of neurotransmitters signalling and structural and functional cerebral changes.

Lisdexamfetamine dimesylate augmentation in adults with persistent executive dysfunction after partial or full remission of major depressive disorder

Evaluate lisdexamfetamine dimesylate (LDX) augmentation of antidepressant monotherapy for executive dysfunction in partially or fully remitted major depressive disorder (MDD). This randomized, placebo-controlled study (NCT00985725) enrolled 143 adults (18-55 years) with mild MDD (Montgomery-Åsberg Depression Rating Scale (MADRS) score ≤ 18) and executive dysfunction (Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A) Self-Report Global Executive Composite (GEC) T score ≥ 60) on stable antidepressant monotherapy for ≥ 8 weeks. After 2 weeks of screening, participants were randomized to 9 weeks of double-blind LDX (20-70 mg/day) or placebo augmentation, followed by 2 weeks of single-blind placebo. The primary end point was change from baseline to week 9/end of study (EOS) in BRIEF-A Self-Report GEC T score; secondary assessments included the BRIEF-A Informant Report, MADRS, and treatment-emergent adverse events (TEAEs). Of 143 randomized participants, 119 completed double-blind treatment (placebo, n=59; LDX, n=60). Mean ± standard deviation (SD) BRIEF-A GEC T scores decreased from baseline (placebo, 74.2 ± 8.88; LDX, 76.8 ± 9.66) to week 9/EOS (placebo, 61.4 ± 14.61; LDX, 55.2 ± 16.15); the LS mean (95% CI) treatment difference significantly favored LDX (-8.0 (-12.7, -3.3); P=0.0009). The LS mean (95% CI) treatment difference for MADRS total score also significantly favored LDX (-1.9 (-3.7, 0.0); P=0.0465). TEAE rates were 73.6% with placebo and 78.9% with LDX; serious TEAE rates were 4.2 and 2.8%. In this trial, LDX augmentation significantly improved executive dysfunction and depressive symptoms in participants with mild MDD. The safety profile of LDX was consistent with prior studies in adults with attention-deficit/hyperactivity disorder.

A randomized, placebo-controlled trial of risperidone augmentation for patients with difficult-to-treat unipolar, non-psychotic major depression

OBJECTIVE

Patients (30-50%) with non-psychotic major depression will not respond despite an adequate trial of antidepressant medication. This study evaluated risperidone as an augmenting agent for patients who failed or only partially responded to an adequate trial of an antidepressant medication.

METHOD

Ninety-seven patients with unipolar non-psychotic major depression who were not responsive to antidepressant monotherapy were randomized to risperidone (0.5-3mg/day) or placebo augmentation in a four-week, double-blind, placebo controlled treatment trial. The primary outcome measure was remission defined by a score of < or =10 on the Montgomery-Asberg Depression Rating Scale (MADRS). Secondary outcomes measures were the Hamilton Rating Scale for Depression, the Clinician Global Impression of Severity scale and the overall satisfaction item of the Quality of Life and Enjoyment Questionnaire.

RESULTS

Subjects in both treatment groups improved significantly over time. The odds of remitting were significantly better for patients in the risperidone vs. placebo arm (OR=3.33, p=.011). At the end of 4 weeks of treatment 52% of the risperidone augmentation group remitted (MADRS< or =10) compared to 24% of the placebo augmentation group (CMH(1)=6.48, p=.011), but the two groups were converging. Patients in the risperidone group also reported significantly more improvement in quality-of-life than patients in the placebo group. There were no between-group differences in the number of adverse events reported, however, weight gain was significantly higher in the group receiving risperidone.

CONCLUSION

Augmentation of an antidepressant with risperidone for patients with difficult-to-treat depression leads to more rapid response and a higher remission rate and better quality-of-life.