Sleep improvement is associated with the antidepressant efficacy of repeated-dose ketamine and serum BDNF levels: a post-hoc analysis

Functional changes in sleep-related arousal after ketamine administration in individuals with treatment-resistant depression

The glutamatergic modulator ketamine is associated with changes in sleep, depression, and suicidal ideation (SI). This study sought to evaluate differences in arousal-related sleep metrics between 36 individuals with treatment-resistant major depression (TRD) and 25 healthy volunteers (HVs). It also sought to determine whether ketamine normalizes arousal in individuals with TRD and whether ketamine's effects on arousal mediate its antidepressant and anti-SI effects. This was a secondary analysis of a biomarker-focused, randomized, double-blind, crossover trial of ketamine (0.5 mg/kg) compared to saline placebo. Polysomnography (PSG) studies were conducted one day before and one day after ketamine/placebo infusions. Sleep arousal was measured using spectral power functions over time including alpha (quiet wakefulness), beta (alert wakefulness), and delta (deep sleep) power, as well as macroarchitecture variables, including wakefulness after sleep onset (WASO), total sleep time (TST), rapid eye movement (REM) latency, and Post-Sleep Onset Sleep Efficiency (PSOSE). At baseline, diagnostic differences in sleep macroarchitecture included lower TST (p = 0.006) and shorter REM latency (p = 0.04) in the TRD versus HV group. Ketamine's temporal dynamic effects (relative to placebo) in TRD included increased delta power earlier in the night and increased alpha and delta power later in the night. However, there were no significant diagnostic differences in temporal patterns of alpha, beta, or delta power, no ketamine effects on sleep macroarchitecture arousal metrics, and no mediation effects of sleep variables on ketamine's antidepressant or anti-SI effects. These results highlight the role of sleep-related variables as part of the systemic neurobiological changes initiated after ketamine administration. Clinical Trials Identifier: NCT00088699.

Patient-reported outcomes on sleep quality and circadian rhythm during treatment with intravenous ketamine for treatment-resistant depression

Background

Intravenous (IV) ketamine is a rapid acting antidepressant used primarily for treatment-resistant depression (TRD). It has been suggested that IV ketamine's rapid antidepressant effects may be partially mediated via improved sleep and changes to the circadian rhythm.

Objectives

This study explores IV ketamine's association with changes in patient-reported sleep quality and circadian rhythm in an adult population with TRD.

Methods

Adult patients (18-64 years) with TRD scheduled for IV ketamine treatment were recruited to complete patient rated outcomes measures on sleep quality using the Pittsburgh Sleep Quality Index (PSQI) and circadian rhythm using the Morningness-Eveningness Questionnaire (MEQ). Over a 4-week course of eight ketamine infusions, reports were obtained at baseline (T0), prior to second treatment (T1), prior to fifth treatment (T2), and 1 week after eighth treatment (T3).

Results

Forty participants with TRD (mean age = 42.8, 45% male) were enrolled. Twenty-nine (72.5%) had complete follow-up data. Paired t tests revealed statistically significant improvements at the end of treatment in sleep quality (PSQI) (p = 0.003) and depressive symptoms (Clinically Useful Depression Outcome Scale-Depression, p < 0.001) while circadian rhythm (MEQ) shifted earlier (p = 0.007). The PSQI subscale components of sleep duration (p = 0.008) and daytime dysfunction (p = 0.001) also improved. In an exploratory post hoc analysis, ketamine's impact on sleep quality was more prominent in patients with mixed features, while its chronobiotic effect was prominent in those without mixed features.

Conclusion

IV ketamine may improve sleep quality and advance circadian rhythm in individuals with TRD. Effects may differ in individuals with mixed features of depression as compared to those without. Since this was a small uncontrolled study, future research is warranted.

The relationship between sleep- and circadian rhythm-related parameters with dietary practices and food intake of sedentary adults: a cross-sectional study

We aimed to explore the link between sleep-related parameters and dietary practices. This cross-sectional exploratory study includes sedentary individuals between 20 and 59 years of age. We applied exigent inclusion and exclusion criteria, such as weight stability and without humor- or sleep-related diseases. Also, shift workers were not included. We evaluated sleep quality (by Pittsburg Sleep Quality Index; PSQI), sleepiness (by Epworth Sleepiness Scale), chronotype (by Morningness Eveningness Questionnaire; MEQ), and social jetlag from sleep dairy. Moreover, Food Practices Measurement Scale was used to assess dietary practices. Food intake estimates (i. e., energy, eating window, and late-night dinner eating) were derived from two 24-h food recalls (R24h). For analysis, dietary practices and energy intake from R24h were considered dependent variables, while PSQI, ESS, MEQ, STJ, EW, and LNDE were considered independent variables. Our sample comprises 42 adults (21 women and 21 men; 35.4 (12.5) y; 25.6 (5.21) kg/m2 BMI; 26.5 (7.97) % body fat). We verified that persons with poor sleep quality showed lower dietary practice scores (MD - 6.68; p = 0.021). Besides, in regression analysis, chronotype (β = 0.266; p = 0.039) was positively associated with dietary practices, and eating window was positively associated with energy intake (β = 267 kcal; p = 0.023). In contrast to our hypothesis, other sleep- and circadian-related variables were not associated with dietary practices or energy intake. In summary, we conclude that morning chronotype appears to be related to better dietary practices from the Food Guide for the Brazilian Population guide and that higher eating window was positively associated with energy intake.

Subanesthetic Dose of Ketamine Administered Before Each Electroconvulsive Therapy Session Improves Antidepressant and Sleep Quality Outcomes: A Randomized, Controlled Trial

OBJECTIVES

The main purpose of this trial is to explore the effects of subanesthetic dose of ketamine on sleep quality and symptoms in patients with major depressive disorder undergoing bitemporal electroconvulsive therapy (ECT).

METHODS

Seventy-one patients with major depressive disorder and sleep disturbance were randomly divided into 2 groups, namely, the ECT without ketamine group (group ES), receiving routine ECT and saline (3 mL) at each ECT session, and the ECT-assisted ketamine group (group KS), which received ECT and ketamine (3 mL) at each ECT session. The 24 Hamilton Depression Rating Scale was used to assess depressive symptoms and the Chinese Pittsburgh Sleep Quality Index was used to evaluate sleep quality.

RESULTS

The patients in group KS required shorter ECT treatment sessions. Patients in group ES had lower sleep efficiency, longer sleep latency, and required more sleep medication than patients in group KS at the end of the ECT course.

CONCLUSIONS

Subanesthetic dose of ketamine improved sleep quality and enhanced ECT therapeutic effects in patients with sleep disturbance.

The Relationship of Early Sleep Improvement With Response to Pharmacotherapy in Unipolar Psychotic Depression

BACKGROUND

Since insomnia and depression are interrelated, improved sleep early in antidepressant pharmacotherapy may predict a positive treatment outcome. We investigated whether early insomnia improvement (EII) predicted treatment outcome in psychotic depression (PD) and examined if there was an interaction effect between EII and treatment type to assess if findings were treatment-specific.

METHODS

This study is a secondary analysis of a randomized trial comparing 7 weeks treatment with the antidepressants venlafaxine, imipramine and venlafaxine plus the antipsychotic quetiapine in PD ( n = 114). Early insomnia improvement, defined as ≥20% reduced insomnia after 2 weeks, was assessed by the Hamilton Rating Scale for Depression (HAM-D-17). Associations between EII and treatment outcome were examined using logistic regressions. Subsequently, we added interaction terms between EII and treatment type to assess interaction effects. The predictive value of EII was compared with early response on overall depression (≥20% reduced HAM-D-17 score after 2 weeks).

RESULTS

EII was associated with response (odds ratio [OR], 7.9; 95% confidence interval [CI], 2.7-23.4; P = <0.001), remission of depression (OR, 6.1; 95% CI, 1.6-22.3; P = 0.009), and remission of psychosis (OR, 4.1; 95% CI, 1.6-10.9; P = 0.004). We found no interaction effects between EII and treatment type on depression outcome. Early insomnia improvement and early response on overall depression had a comparable predictive ability for treatment outcome.

CONCLUSIONS

Early insomnia improvement was associated with a positive outcome in pharmacotherapy of PD, regardless of the medication type. Future studies are needed to confirm our findings and to examine the generalizability of EII as predictor in treatment of depression.

Predicting efficacy of sub-anesthetic ketamine/esketamine i.v. dose during course of cesarean section for PPD prevention, utilizing traditional logistic regression and machine learning models

OBJECTIVE

Increasing researches supported that intravenous ketamine/esketamine during the perioperative period of cesarean section could prevent postpartum depression(PPD). With the effective rate ranging from 87.2 % to 95.5 % in PPD, ketamine/esketamine's responsiveness was individualized. To optimize ketamine dose/form based on puerpera prenatal characteristics, reducing adverse events and improving the total efficacy rate, prediction models were developed to predict ketamine/esketamine's efficacy.

METHOD

Based on two randomized controlled trials, 12 prenatal features of 507 women administered the ketamine/esketamine intervention were collected. Traditional logistics regression, SVM, random forest, KNN and XGBoost prediction models were established with prenatal features and dosage regimen as predictors.

RESULTS

According to the logistic regression model (ain = 0.10, aout = 0.15, area under the receiver operating characteristic curve, AUC = 0.728), prenatal Edinburgh Postnatal Depression Scale (EPDS) score ≥ 10, thoughts of self-injury and bad mood during pregnancy were associated with poorer ketamine efficacy in PPD prevention, whilst a high dose of esketamine (0.25 mg/kg loading dose+2 mg/kg PCIA) was the most effective dosage regimen and esketamine was more recommended rather than ketamine in PPD. The AUCvalidation set of KNN and XGBoost model were 0.815 and 0.651, respectively.

CONCLUSION

Logistic regression and machine learning algorithm, especially the KNN model, could predict the effectiveness of ketamine/esketamine iv. during the course of cesarean section for PPD prevention. An individualized preventative strategy could be developed after entering puerpera clinical features into the model, possessing great clinical practice value in reducing PPD incidence.

The effects of ketamine and classic hallucinogens on neurotrophic and inflammatory markers in unipolar treatment-resistant depression: a systematic review of clinical trials

Although results are still preliminary, ketamine and classical hallucinogens have shown promise in recent years as novel, fast-acting antidepressants, especially for the treatment of unipolar treatment-resistant depression (TRD). Depression also seems to be related to abnormal levels of peripheral inflammatory and neurotrophic biomarkers, which may one day help to diagnose of this disorder. In this context, this systematic review of clinical trials evaluated the current evidence that relates the antidepressant effects of ketamine and classical hallucinogens on TRD with changes in inflammatory and neurotrophic biomarkers. Twelve studies were found (n = 587), 2 with oral ayahuasca (1 mL/kg) and 10 with ketamine (mostly intravenous 0.5 mg/kg) administration. Results for all biomarkers assessed were contradictory and thus inconclusive. Randomized controlled trials with bigger samples and higher statistical power are warranted to clarify if peripheral biomarkers can confidently be used to indicate and measure ketamine's and classical hallucinogens' antidepressant effect. The PROSPERO ID for this study is CRD42021249089.

Functional connectivity differences in the amygdala are related to the antidepressant efficacy of ketamine in patients with anxious depression

BACKGROUND

The antidepressant effects of ketamine in patients with anxious depression (AD) remain unclear. Functional connectivity (FC) differences in the amygdala have been linked to depression improvement after ketamine treatment in depressed patients, but their role in AD patients is uncertain. We investigated the correlation between depression improvement after ketamine treatment and amygdala FC in AD patients.

METHODS

Thirty-one AD patients and 18 non-anxious depression (NAD) patients received six intravenous ketamine infusions (0.5 mg/kg) over two weeks. AD patients were further divided into responders (defined as a ≥50% MADRS total score reduction on day 13) and non-responders. The FC of the amygdala subregions, including the laterobasal amygdala (LBA), centromedial amygdala (CMA), and superficial amygdala, were compared between the groups. Receiver operating characteristic curves were used to predict treatment response after ketamine infusions.

RESULTS

The baseline FC difference in the left LBA and the left precuneus between responders and non-responders among AD patients was found to be associated with depression improvement and was a significant predictor of treatment response to ketamine. A marked reduction in baseline LBA-precuneus FC after ketamine infusion was observed in responders. Unlike in patients with NAD, a lower right CMA-right middle temporal gyrus FC was found in AD patients.

LIMITATIONS

The sample size is rather small.

CONCLUSIONS

Our findings may suggest that amygdala FC is a significant predictor of treatment response to ketamine infusions in patients with AD. Further studies exploring the potential antidepressant mechanisms of ketamine may aid in the treatment of AD patients.

Advances in the pathophysiology of bipolar disorder

PURPOSE OF REVIEW

Due to bipolar disorder clinical heterogeneity, a plethora of studies have provided new genetic, epigenetic, molecular, and cellular findings associated with its pathophysiology.

RECENT FINDINGS

Genome-wide association studies and epigenetic evidence points to genotype-phenotype interactions associated with inflammation, oxidative stress, abnormalities in signaling pathways, hypothalamic-pituitary-adrenal axis, and circadian rhythm linked to mitochondrial dysfunction in bipolar disorder. Although the literature is constantly increasing, most of the genetic variants proposed as biomarkers remain to be validated by independent groups and use bigger samples and longitudinal approaches to enhance their power and predictive ability.

SUMMARY

Regardless of which of the mechanisms described here plays a primary or secondary role in the pathophysiology of bipolar disorder, all of these interact to worsen clinical outcomes for patients. Identifying new biomarkers for early detection, prognosis, and response to treatment might provide novel targets to prevent progression and promote general well being.

Stress, mental disorder and ketamine as a novel, rapid acting treatment

The experience of stress is often utilised in models of emerging mental illness and neurobiological systems are implicated as the intermediary link between the experience of psychological stress and the development of a mental disorder. Chronic stress and prolonged glucocorticoid exposure have potent effects on neuronal architecture particularly in regions that modulate the hypothalamic-pituitary-adrenal (HPA) axis and are commonly associated with psychiatric disorders. This review provides an overview of stress modulating neurobiological and neurochemical systems which underpin stress-related structural and functional brain changes. These changes are thought to contribute not only to the development of disorders, but also to the treatment resistance and chronicity seen in some of our most challenging mental disorders. Reports to date suggest that stress-related psychopathology is the aetiological mechanism of these disorders and thus we review the rapid acting antidepressant ketamine as an effective emerging treatment. Ketamine, an N-methyl D-aspartate (NMDA) receptor antagonist, is shown to induce a robust treatment effect in mental disorders via enhanced synaptic strength and connectivity in key brain regions. Whilst ketamine's glutamatergic effect has been previously examined, we further consider ketamine's capacity to modulate the HPA axis and associated pathways.

Effect of Intraoperative Esketamine Infusion on Postoperative Sleep Disturbance After Gynecological Laparoscopy: A Randomized Clinical Trial

IMPORTANCE

Postoperative sleep disturbance (PSD) is common in patients after surgery.

OBJECTIVE

To examine the effect of intraoperative esketamine infusion on the incidence of PSD in patients who underwent gynecological laparoscopic surgery.

DESIGN, SETTING, AND PARTICIPANTS

This single-center, double-blind, placebo-controlled randomized clinical trial was conducted from August 2021 to April 2022 in the First Affiliated Hospital of Zhengzhou University in China. Participants included patients aged 18 to 65 years with an American Society of Anesthesiologist Physical Status classification of I to III (with I indicating a healthy patient, II a patient with mild systemic disease, and III a patient with severe systemic disease) who underwent gynecological laparoscopic surgery. Patients were randomly assigned to either the esketamine group or control group. Data were analyzed using the per protocol principle.

INTERVENTIONS

Patients in the esketamine group received a continuous infusion of esketamine, 0.3 mg/kg/h, intraoperatively. Patients in the control group received an equivalent volume of saline.

MAIN OUTCOMES AND MEASURES

The primary outcome was the incidence of PSD on postoperative days (PODs) 1 and 3. Postoperative sleep disturbance was defined as a numeric rating scale score of 6 or higher or an Athens Insomnia Scale score of 6 points or higher. The secondary outcomes included postoperative anxiety and depression scores using the Hospital Anxiety and Depression Scale, postoperative pain using the visual analog scale, postoperative hydromorphone consumption, and risk factors associated with PSD.

RESULTS

A total of 183 female patients were randomized to the control group (n = 91; median [IQR] age, 45 [35-49] years) and the esketamine group (n = 92; median [IQR] age, 43 [32-49] years). The incidence of PSD in the esketamine group was significantly lower than in the control group on POD 1 (22.8% vs 44.0%; odds ratio [OR], 0.38 [95% CI, 0.20-0.72]; P = .002) and POD 3 (7.6% vs 19.8%; OR, 0.33 [95% CI, 0.13-0.84]; P = .02). There were no differences in postoperative depression and anxiety scores between the 2 groups. Postoperative hydromorphone consumption in the first 24 hours (3.0 [range, 2.8-3.3] mg vs 3.2 [range, 2.9-3.4] mg; P = .04) and pain scores on movement (3 [3-4] vs 4 [3-5] points; P < .001) were significantly lower in the esketamine group than in the control group. On multivariable logistic regression, preoperative depression (OR, 1.31; 95% CI, 1.01-1.70) and anxiety (OR, 1.67; 95% CI, 1.04-1.80) scores, duration of anesthesia (OR, 1.04; 95% CI, 1.00-1.08), and postoperative pain score (OR, 1.92; 95% CI, 1.24-2.96) were identified as risk factors associated with PSD.

CONCLUSIONS AND RELEVANCE

Results of this trial showed the prophylactic effect of intraoperative esketamine infusion on the incidence of PSD in patients who underwent gynecological laparoscopic surgery. Further studies are needed to confirm these results.

TRIAL REGISTRATION

Chinese Clinical Trial Registry Identifier: ChiCTR2100048587.

Functional connectivity between the habenula and default mode network and its association with the antidepressant effect of ketamine

BACKGROUND

Recently, an animal model for depression has shown that ketamine, an N-methyl- d-aspartate receptor (NMDAR) antagonist, elicits a rapid-acting antidepressant effect by blocking NMDAR-dependent bursting in the lateral habenula (Hb). However, evidence from human studies remains scarce.

METHODS

This study explored the changes of resting-state functional connectivity (FC) of the Hb in responders and nonresponders who was diagnosed with unipolar or bipolar depression before and after ketamine treatment. The response was defined as a ≥50% reduction in the total MADRS score at Day 13 (24 h following the sixth infusion) in comparison with the baseline score. Correlation analyses were performed to identify an association between symptom improvement and the signals of the significantly different brain regions detected in the above imaging analysis.

RESULTS

In the post-hoc region-of-interest analysis, an enhanced baseline FC between Hb and several hubs of the default mode network (including angulate cortex, precuneus, medial prefrontal cortex, and middle temporal cortex) was observed in responders (≥50% decrease in the Montgomery-Asberg Scale at 2 weeks) compared with nonresponders.

CONCLUSIONS

These pilot findings may suggest a potential neural mechanism by which ketamine exerts its robust antidepressant efficacy via downregulation of aberrant habenular FC with parts of the default mode network.

Low-dose ketamine infusion for treating subjective cognitive, somatic, and affective depression symptoms of treatment-resistant depression

BACKGROUNDS

Whether the antidepressant effects of low-dose ketamine infusion and the therapeutic impact of Val66Met brain-derived neurotrophic factor (BDNF) polymorphism vary across different depression symptom domains, namely affective, cognitive, and somatic, remains unclear.

METHODS

We-reanalyzed the data of Adjunctive Ketamine Study of Taiwanese Patients with Treatment-Resistant Depression (TRD). A total of 71 patients with TRD were randomized to three infusion groups: 0.5 and 0.2 mg/kg ketamine groups and the normal saline placebo group. The Beck Depression Inventory-II (BDI-II) was used to obtain self-reported scores prior to infusion and 240 min after infusion and sequentially on days 3, 7, and 14 after infusion. The three-factor model of cognitive, somatic, and affective depressive symptoms that is based on the BDI-II and proposed by Beck et al. was applied in the current study. The Val66Met BDNF polymorphism was genotyped.

RESULTS

Ketamine infusion exerted rapid and sustained antidepressant effects on the affective (p = 0.014) and cognitive (p = 0.005) depression symptom domains but not on the somatic (p = 0.085) depression symptom domain. Only patients with TRD harboring any Val allele at the BDNF rs6265 polymorphism were more likely to respond (p = 0.011) to low-dose ketamine infusion.

DISCUSSION

Additional studies should elucidate different mechanisms underlying the effects of ketamine infusion on cognitive, affective, and somatic depression symptom domains in patients with TRD.

A wake-up call: Sleep physiology and related translational discrepancies in studies of rapid-acting antidepressants

Depression is frequently associated with sleep problems, and clinical improvement often coincides with the normalization of sleep architecture and realignment of circadian rhythm. The effectiveness of treatments targeting sleep in depressed patients, such as sleep deprivation, further demonstrates the confluence of sleep and mood. Moreover, recent studies showing that the rapid-acting antidepressant ketamine influences processes related to sleep-wake neurobiology have led to novel hypotheses explaining rapid and sustained antidepressant effects. Despite the available evidence, studies addressing ketamine’s antidepressant effects have focused on pharmacology and often overlooked the role of physiology. To explore this discrepancy in research on rapid-acting antidepressants, we examined articles published between 2009–2019. A keyword search algorithm indicated that vast majority of the articles completely ignored sleep. Out of the 100 most frequently cited preclinical and clinical research papers, 89 % and 71 %, respectively, did not mention sleep at all. Furthermore, only a handful of these articles disclosed key experimental variables, such as the times of treatment administration or behavioral testing, let alone considered the potential association between these variables and experimental observations. Notably, in preclinical studies, treatments were preferentially administered during the inactive period, which is the polar opposite of clinical practice and research. We discuss the potential impact of this practice on the results in the field. Our hope is that this perspective will serve as a wake-up call to (re)-examine rapid-acting antidepressant effects with more appreciation for the role of sleep and chronobiology.

Effect of Transcutaneous Auricular Vagus Nerve Stimulation on Protracted Alcohol Withdrawal Symptoms in Male Alcohol-Dependent Patients

Protracted alcohol withdrawal symptoms (PAWS), characterized by the presence of substance-specific signs and symptoms (including anxiety, irritability, mood instability, insomnia, and cravings), make alcohol abstinence difficult and increase the risk of relapse in recovering alcoholics. The goal of this study was to evaluate the effect of transcutaneous auricular vagus nerve stimulation (taVNS) on PAWS and plasma brain-derived neurotrophic factor (BDNF), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and leptin levels in patients with alcohol dependency. A total of 114 patients with alcohol dependence were randomly divided into two groups: the treatment group and the control group. The patients in the treatment group were treated with taVNS of the bilateral auricular concha using an ear vagus nerve stimulator. The Pennsylvania Alcohol Craving Scale was used to evaluate the extent of craving for alcohol. The Self-Rating Anxiety Scale and Self-Rating Depression Scale (SDS) were used to evaluate the extent of anxiety and depression symptoms, respectively. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality. Enzyme-linked immunosorbent assay was used to measure plasma BDNF, IL-6, TNF-α, and leptin levels. The results showed that the SDS and PSQI scores were significantly lower in the treatment group than in the control group. Moreover, compared with the control group, the average BDNF levels in the treatment group were significantly increased. These results suggest that taVNS could improve the depression symptoms and sleep quality in alcohol-dependent patients after withdrawal, which might be related to the upregulation of plasma BDNF levels.