Esketamine for treatment‑resistant depression: A review of clinical evidence (Review)

Psychometric properties of the 23-Item Clinician Administered Dissociative States Scale (CADSS) in a psychological trauma population

OBJECTIVE

Dissociative symptoms are both a pathological consequence of exposure to psychological trauma as well as a side effect of N-methyl-d-aspartate (NMDA) receptor antagonist medications; therefore, accurate and valid assessment of these symptoms is important. The psychometric properties of the 23-item Clinician Administered Dissociative States Scale (CADSS) have been characterized in the ketamine and esketamine literatures. Here, we examine its performance in a sample with and without posttraumatic stress disorder (PTSD) and a history of exposure to psychological trauma.

METHODS

Participants with a history of psychological trauma with (N = 148) and without (N = 100) the diagnosis of PTSD and healthy participants without a psychiatric disorder or history of trauma (N = 28) were assessed with the 23-item CADSS and other psychometric and neuropsychological assessments. Analyses were performed to examine internal consistency, convergent and discriminant validity, factor structure, differential performance in populations reported to be more or less likely to report dissociative symptoms (e.g., patients with and without PTSD), and sensitivity to change resulting from exposure to trauma-related sights and sounds.

RESULTS

The 23-item CADSS was found to have high internal consistency (Cronbach's alpha 0.91) and a single-factor structure. CADSS total scores in trauma-exposed participants with PTSD were higher than those in trauma-exposed participants without PTSD and non-traumatized non-PTSD participants. Finally, veterans with Iraq combat-related PTSD showed a significant increase in CADSS total score after exposure to combat-related slides and sounds.

CONCLUSION

The 23-item CADSS, already validated as a tool to measure dissociation related to administration of NMDA receptor antagonist medication, performs in a reliable and valid manner in the assessment of dissociation in psychologically traumatized participants.

Ketamine, Esketamine, and Arketamine: Their Mechanisms of Action and Applications in the Treatment of Depression and Alleviation of Depressive Symptoms

Research over the past years has compared the enantiomers (S)-ketamine (esketamine) and (R)-ketamine (arketamine) of the previously known racemic mixture called ketamine (R/S-ketamine). Esketamine has been found to be more potent, offering three times stronger analgesic effects and 1.5 times greater anesthetic efficacy than arketamine. It provides smoother anesthesia with fewer side effects and is widely used in clinical settings due to its neuroprotective, bronchodilatory, and antiepileptic properties. Approved by the FDA and EMA in 2019, esketamine is currently used alongside SSRIs or SNRIs for treatment-resistant depression (TRD). On the other hand, arketamine has shown potential for treating neurological disorders such as Alzheimer's, Parkinson's, and multiple sclerosis, offering possible antidepressant effects and anti-inflammatory benefits. While esketamine is already in clinical use, arketamine's future depends on further research to address its safety, efficacy, and optimal dosing. Both enantiomers hold significant clinical value, with esketamine excelling in anesthesia, and arketamine showing promise in neurological and psychiatric treatments.

Perioperative esketamine administration for prevention of postpartum depression after the cesarean section: A systematic review and meta-analysis

BACKGROUND

Postpartum Depression (PPD) exerts a substantial negative effect on maternal well-being post-delivery, particularly among Cesarean Section (C/S) recipients. In this study, we aimed to review the efficacy of perioperative esketamine, the S-enantiomer of ketamine, in preventing PPD incidence and depressive symptoms as measured with the Edinburgh Postnatal Depression Scale (EPDS) after C/S.

METHODS

A systematic search for relevant articles was conducted in Scopus, PubMed, Web of Sciences, and PsycINFO until April 6, 2024. Meta-analyses were conducted using random-effect models to compare the PPD incidence and EPDS scores via log odds ratio and Hedge's g, respectively, during the first week post-C/S and at 42 days post-C/S in the esketamine and control group.

RESULTS

Fourteen studies, including 12 randomized controlled trials and 2 retrospective cohorts, were reviewed. Our meta-analyses found lower PPD incidence during the first week (log odds ratio: -0.956 [95 % confidence interval: -1.420, -0.491]) and at day 42 post-C/S (log odds ratio: -0.989 [95 % confidence interval: -1.707, -0.272]) among patients administered esketamine compared to controls. Additionally, EPDS scores for the esketamine group were significantly lower than controls during the first week (Hedge's g: -0.682 [95 % confidence interval: -1.088, -0.276]) and at day 42 post-C/S (Hedge's g: -0.614 [95 % confidence interval: -1.098, -0.129]).

LIMITATIONS

Presence of various concomitant medications and heterogeneous study designs.

CONCLUSION

Our review highlights the potential impact of esketamine in PPD prevention, as well as in alleviating depressive symptoms post-C/S, regardless of PPD occurrence, therefore suggesting the benefits of adding esketamine to peri-C/S analgesic regimen.

Profiling the combination of bupropion and dextromethorphan as a treatment option for major depressive disorder

INTRODUCTION

Major Depressive Disorder (MDD) is a common mental health disorder marked by sadness, hopelessness, and anhedonia. Various therapies exist, but their effectiveness is limited. Dextromethorphan hydrobromide combined with bupropion hydrochloride (Auvelity®) is a recently approved alternative for treating this condition in adults.

AREAS COVERED

This review summarizes the neurobiology of major depression and delves into the pharmacology, efficacy, safety, and tolerability of dextromethorphan plus bupropion in adult patients. It is based on observational studies, clinical trials, and other secondary studies obtained through systematic literature searches.

EXPERT OPINION

The combination of bupropion and dextromethorphan as a new pharmacotherapy for mental health is an interesting addition to the treatment options that can be used for MDD. The combination can be used in a range of scenarios, including as a first line therapy, as a second option when a patient has failed to achieve remission with a serotonin targeting agent, and for treatment resistant depression. Further research for other indications, including addiction disorders, may provide exciting results. Although a new combination, clinicians will be very familiar with both agents, increasing their acceptability. This pharmacotherapy also may bring increased impetus for discovering other combinations that may have beneficial synergistic effects.

Unlocking new avenues for neuropsychiatric disease therapy: the emerging potential of Peroxisome proliferator-activated receptors as promising therapeutic targets

RATIONALE

Peroxisome proliferator-activated receptors (PPARs) are transcription factors that regulate various physiological processes such as inflammation, lipid metabolism, and glucose homeostasis. Recent studies suggest that targeting PPARs could be beneficial in treating neuropsychiatric disorders by modulating neuronal function and signaling pathways in the brain. PPAR-α, PPAR-δ, and PPAR-γ have been found to play important roles in cognitive function, neuroinflammation, and neuroprotection. Dysregulation of PPARs has been associated with neuropsychiatric disorders like bipolar disorder, schizophrenia, major depression disorder, and autism spectrum disorder. The limitations and side effects of current treatments have prompted research to target PPARs as a promising novel therapeutic strategy. Preclinical and clinical studies have shown the potential of PPAR agonists and antagonists to improve symptoms associated with these disorders.

OBJECTIVE

This review aims to provide an overview of the current understanding of PPARs in neuropsychiatric disorders, their potential as therapeutic targets, and the challenges and future directions for developing PPAR-based therapies.

METHODS

An extensive literature review of various search engines like PubMed, Medline, Bentham, Scopus, and EMBASE (Elsevier) databases was carried out with the keywords "PPAR, Neuropsychiatric disorders, Oxidative stress, Inflammation, Bipolar Disorder, Schizophrenia, Major depression disorder, Autism spectrum disorder, molecular pathway".

RESULT & CONCLUSION

Although PPARs present a hopeful direction for innovative therapeutic approaches in neuropsychiatric conditions, additional research is required to address obstacles and convert this potential into clinically viable and individualized treatments.

The cyclical revival of psychedelics in psychiatric treatment

There is an increasing demand for effective treatments for depression, particularly for individuals grappling with treatment-resistant depression. Over recent years, a surge of interest has focused on exploring the safety and efficacy of psilocybin as a potential treatment for depression. However, preliminary findings from phase 2 studies have been inconclusive, prompting critical examination of issues such as maintaining blinding and the role of adjunctive psychotherapy. The maintenance of double-blinding and the role of adjunctive psychotherapy introduce biases that complicate the attainment of conclusive results in clinical research. Examining historical data reveals a recurrent pattern linked to the use of psychoactive substances, which starts with an excess of optimism and ends with general addictive behaviors and a heightened risk of serious public health problems. Considering these findings, a cautious and measured approach is imperative, given that the efficacy and safety of psilocybin treatment have yet to be unequivocally established. The potential for excessive optimism among researchers is a notable concern, as unwarranted enthusiasm may inadvertently facilitate the widespread adoption of this treatment without sufficient empirical support. In navigating the complexities of depression treatment, it is necessary to strike a balance between innovation and prudence to ensure evidence-based advancement of therapeutic approaches.

Current evidence and future perspectives in the exploration of sleep-related eating disorder-a systematic literature review

Sleep-related eating disorder (SRED) is a non-REM parasomnia with potentially significant negative effects on general health (dangerous activities during night eating episodes, obesity, or metabolic syndrome, for example). Although the history of SRED encompasses more than six decades, public awareness and even the awareness of the mental health specialists of this disorder is very limited, a phenomenon that hinders the development of research in this field. Therefore, a systematic review based on PRISMA 2020 guidelines explored the available evidence for SRED found in four electronic databases (PubMed, Cochrane Collaboration, Google Scholar, and Clarivate/Web of Science). A number of 94 primary and secondary reports were retrieved, investigating aspects regarding the risk factors, epidemiology, clinical data and differential diagnosis, epidemiology, structured evaluation, and treatment of SRED. Based on the results of these reports, Z-drugs, but also certain benzodiazepines, antidepressants, antipsychotics, and psychostimulants may trigger the onset of SRED. Psychiatric and neurologic disorders have also been associated with SRED, either as risk factors or comorbid conditions. Cerebral glucose metabolism dysfunctions, neurotransmitter dysfunctions, and genetic factors have been invoked as pathogenetic contributors. Structured assessment of SRED is possible, but there is a dearth of instruments dedicated to this purpose. Data on the prevalence and treatment of SRED exist, but good-quality epidemiological studies and clinical trials are still missing. In conclusion, future research is expected to address the shortcomings of SRED exploration by creating the conditions for better quality and larger group clinical research. The need for such investigation is granted by the importance of this pathology and its negative functional consequences.

New Light on Prions: Putative Role of PrPc in Pathophysiology of Mood Disorders

Mood disorders are highly prevalent and heterogenous mental illnesses with devastating rates of mortality and treatment resistance. The molecular basis of those conditions involves complex interplay between genetic and environmental factors. Currently, there are no objective procedures for diagnosis, prognosis and personalization of patients' treatment. There is an urgent need to search for novel molecular targets for biomarkers in mood disorders. Cellular prion protein (PrPc) is infamous for its potential to convert its insoluble form, leading to neurodegeneration in Creutzfeldt-Jacob disease. Meanwhile, in its physiological state, PrPc presents neuroprotective features and regulates neurotransmission and synaptic plasticity. The aim of this study is to integrate the available knowledge about molecular mechanisms underlying the impact of PrPc on the pathophysiology of mood disorders. Our review indicates an important role of this protein in regulation of cognitive functions, emotions, sleep and biological rhythms, and its deficiency results in depressive-like behavior and cognitive impairment. PrPc plays a neuroprotective role against excitotoxicity, oxidative stress and inflammation, the main pathophysiological events in the course of mood disorders. Research indicates that PrPc may be a promising biomarker of cognitive decline. There is an urgent need of human studies to elucidate its potential utility in clinical practice.

Supplemental low-dose esketamine to propofol versus propofol alone on perioperative characteristics in children undergoing surgery: a prospective randomized controlled trial

BACKGROUND

Limited data exist regarding the use of the esketamine-propofol combination (esketofol) in pediatric surgery. This study aimed to investigate the effect of esketofol versus propofol alone on the perioperative characteristics of children undergoing minor surgery.

METHODS

Eighty-four children aged two to six years were randomly assigned to either the propofol group or the esketofol group. Intraoperative outcomes included bispectral index, dosage of anesthetics, and extubation time. Postoperative outcomes comprised oropharyngeal airway usage, time to orientation, time to eye-opening, length of stay in the post-anesthesia care unit, the need for rescue opioids, pain rating using the Face, Legs, Activity, Cry, Consolability (FLACC) Scale, Pediatric Anesthesia Emergence Delirium Score, nausea and vomiting, and psychotomimetic symptoms. The FLACC pain score was the primary outcome, and the remaining parameters were considered secondary outcomes.

RESULTS

The FLACC Score (2 [1, 3.3] vs. 4 [3, 5.3], P<0.001) and frequency of rescue opioids (14.3% vs. 33.3%, P=0.040) were significantly lower, while Bispectral Index (BIS) was higher (P<0.001) in the esketofol group compared with the propofol group. Moreover, the time to orientation and length of stay in the post-anesthesia care unit (PACU) were significantly longer in the esketofol group compared with the propofol group (P=0.029 and P=0.025, respectively). The other outcomes were similar between the two groups.

CONCLUSIONS

Esketofol reduces postoperative pain and the need for rescue opioids, but it extends recovery time in the PACU and increases BIS without affecting other outcomes.

Impact of Adjunctive VNS on Drug Load, Depression Severity, and Number of Neuromodulatory Maintenance Treatments

Vagus nerve stimulation (VNS) is a long-term adjunctive treatment option in patients with difficult-to-treat depression (DTD). A total of n = 20 patients (mean age 52.6 years) were included in the multicenter, prospective, observational, naturalistic RESTORE-LIFE study and were treated with adjunctive VNS as an add-on to treatment as usual. Exploratory and secondary outcome parameters from a single center were investigated for this present analysis. The overall mean drug load slightly decreased from 4.5 at baseline to 4.4 at 12 months (Z = -0.534, p = 0.594). The drug load was lower in previous electroconvulsive therapy (ECT) responders than in non-responders. There was a reduction in the mean number of hospitalizations per month after VNS implantation (Z = 1.975, p = 0.048) and a significant decrease in the mean Montgomery Åsberg Depression Rating Scale (MADRS) score from 27.3 at baseline to 15.3 at 12 months (T = 4.230, degree of freedom (df) = 19, p = 0.001). A history of ECT response at baseline was associated with greater improvement in the MADRS score after 12 months of VNS (F = 8.171, p = 0.013). The number of neuromodulatory maintenance treatments decreased during the follow-up period. In summary, there was an alleviation in the burden of illness among DTD patients treated with VNS.

Exploring Esketamine's Therapeutic Outcomes as an FDA-Designated Breakthrough for Treatment-Resistant Depression and Major Depressive Disorder With Suicidal Intent: A Narrative Review

The expansive spectrum of major depressive disorder (MDD) continues to pose challenges for psychiatrists to treat effectively. Oral antidepressant (OAD) medications that alter monoamine neurotransmitters, mainly selective serotonin reuptake inhibitors (SSRIs) and selective norepinephrine reuptake inhibitors (SNRIs), have been the mainstay of therapy for decades. Although these drugs have been largely beneficial, a considerable subset of patients do not respond adequately to multiple conventional therapies administered for an appropriate length of time, leading to a diagnosis of treatment-resistant depression (TRD). Ketamine, a non-monoaminergic drug, has long been known for its beneficial effects on TRD when given intravenously (IV). Between 2019 and 2020, an intranasal formulation of the S (+) enantiomer of racemic ketamine, esketamine (ESK), was granted "breakthrough designation" by the FDA and approved for the indications of TRD and MDD patients exhibiting acute suicidal intent. The objective of this narrative review was to review the academic literature and collect clinical evidence that may corroborate intranasal ESK's effectiveness for its approved indications while addressing its safety and tolerability profile, adverse effects, and impact on cognition. An overview of the drug's origins, pharmacology, and standard treatment regimen are provided. The outcomes from double-blinded randomized control trials (DB-RCTs) of ESK are outlined to demonstrate the efficacy and safety data leading to its FDA approval, along with its long-term post-market safety outcomes. Comparative trials between ESK and ketamine are then evaluated to highlight ESK's consideration as a more practical alternative to ketamine in common clinical practice. The authors further discuss currently approved and developing therapies for TRD, propose future research directions, and identify the inherent limitations of the review and further research. To conduct the research required, three digital databases (PubMed, Medline, and ClinicalTrials.gov) were queried to search for key terms, including ketamine, esketamine, treatment-resistant depression, and biomarkers, using automation tools along with selective search engine results. After streamlining the results by title and abstract and removing duplicates, a total of 37 results were chosen, of which 18 are clinical trials. A reduction in the Montgomery-Asberg Depression Rating Scale (MADRS) score was the primary efficacy endpoint for most of these clinical trials. In conclusion, intranasal ESK, when used as an adjunct to market OADs, shows greater efficacy in treating TRD and MDD with suicidal intent compared to OADs and placebo alone and provides a more suitable alternative to IV ketamine. It is important to note that further research is required to fully understand the novel mechanism of action of ESK, as well as the establishment of a consensus definition of TRD, which may facilitate better detection and treatment protocols. More focused quantitative and qualitative ESK studies are needed, as well as those pertaining to its use in patients with co-existing mental illnesses.

Efficacy, Safety, and Tolerability of Psychedelics in Treatment-Resistant Depression (TRD)

Major depressive disorder (MDD) is a highly prevalent psychiatric disorder, associated with substantial burden and large economical costs. Notwithstanding various conventional antidepressant treatment options, a large portion of depressed people (ca. 30%) fails to respond to first-line treatment, resulting in treatment-resistant depression (TRD). Although non-response to multiple antidepressant interventions is a common outcome, a consensus definition of TRD is not yet available. In practice, TRD is applied when two or more successive treatments with different antidepressants are not working. The last decade's intense research into new medicines for TRD has led to two developments, using typical or serotonergic (psilocybin, ayahuasca) and atypical (glutamatergic) psychedelics (ketamine, esketamine). Both approaches, although via different entrance mechanism, exhibit a fast onset but also long-lasting antidepressant effect far beyond the biological presence of the drug in the body, strongly indicating that downstream mechanisms activated by signaling cascades in the brain are involved. The present chapter describes the clinical development of psilocybin and esketamine for TRD and discusses the problems involved in the use of a proper placebo because of the psychotomimetic (psilocybin) or dissociative (ketamine) effects that interfere with performing "blind" studies. Nevertheless, intranasal esketamine was developed and approved for TRD, whereas psilocybin has shown positive results. Adverse effects and tolerability of both drugs in the dose ranges used are generally acceptable. The emergence of anti-TRD medicines for treatment of a very severe disease is a breakthrough in psychiatry.

Baseline characteristics of a European patient population with difficult-to-treat depression (RESTORE-LIFE) treated with adjunctive vagus nerve stimulation

BACKGROUND

Major depressive disorder is a complex heterogeneous disorder. Treatment is especially challenging for patients with "difficult-to-treat depression" (DTD): a less stigmatizing and more clinically relevant framework defining depression that continues to cause significant burden despite usual treatment efforts.

METHODS

RESTORE-LIFE is a prospective, observational, multicenter, post-market study being conducted in Europe and is designed to reflect real-world clinical application of adjunctive Vagus Nerve Stimulation Therapy (VNS) for DTD. Baseline characteristics of RESTORE-LIFE patients were analyzed and compared to published treatment-resistant depression (TRD) trials.

RESULTS

This analysis includes the initial 98 RESTORE-LIFE patients who commenced treatment with VNS. Patients had a mean of 11.4 failed anti-depressant treatments, 1.1 suicide attempts, 87 % had prior electroconvulsive therapy, and 36 % had an endocrine/metabolic comorbidity. On average, disease severity was comparable to that in TRD trials (n = 15,463). However, RESTORE-LIFE patients appear to have been experiencing DTD for a longer duration and their DTD was characterized by a lack of positive mental health and meaningfulness of life, to a greater degree than by excess of negative mood. Despite high comorbidity rates in RESTORE-LIFE, VNS implantation was performed safely with no discontinuations due to surgical adverse events.

LIMITATIONS

RESTORE-LIFE enrolls any patient receiving adjunctive VNS for DTD. Prescription of VNS may be biased by differences in practices amongst sites and countries.

CONCLUSIONS

The present analysis offers insight into contemporary real-world use of VNS Therapy for DTD in Europe representing a comprehensive characterization of DTD and how this population may differ from those in the TRD literature.

Preclinical models of treatment-resistant depression: challenges and perspectives

Treatment-resistant depression (TRD) is a subgroup of major depressive disorder in which the use of classical antidepressant treatments fails to achieve satisfactory treatment results. Although there are various definitions and grading models for TRD, common criteria for assessing TRD have still not been established. However, a common feature of any TRD model is the lack of response to at least two attempts at antidepressant pharmacotherapy. The causes of TRD are not known; nevertheless, it is estimated that even 60% of TRD patients are so-called pseudo-TRD patients, in which multiple biological factors, e.g., gender, age, and hormonal disturbances are concomitant with depression and involved in antidepressant drug resistance. Whereas the phenomenon of TRD is a complex disorder difficult to diagnose and successfully treat, the search for new treatment strategies is a significant challenge of modern pharmacology. It seems that despite the complexity of the TRD phenomenon, some useful animal models of TRD meet the construct, the face, and the predictive validity criteria. Based on the literature and our own experiences, we will discuss the utility of animals exposed to the stress paradigm (chronic mild stress, CMS), and the Wistar Kyoto rat strain representing an endogenous model of TRD. In this review, we will focus on reviewing research on existing and novel therapies for TRD, including ketamine, deep brain stimulation (DBS), and psychedelic drugs in the context of preclinical studies in representative animal models of TRD.

Effect of single intravenous injection of esketamine on postpartum depression after labor analgesia and potential mechanisms: a randomized, double-blinded controlled trial

BACKGROUND

The study was designed to investigate effects of single intravenous injection of esketamine on the incidence of postpartum depression (PPD) after labor analgesia and explore the potential mechanisms.

METHODS

A total of 120 women who underwent labor analgesia by epidural analgesia pump were enrolled and divided into two groups randomly. Esketamine at a dose of 0.2 mg/kg was intravenously injected after fetal disengagement in the test group and placebo was administered in the control group. The occurrence of PPD and side effects after delivery were recorded. Some indicators related to stress and inflammation were measured before labor analgesia and at 24 h, 1 week, and 6 weeks after delivery in this study. Data were analyzed by independent t-test, repeated measures analysis of variance and Chi-square test in SPSS software (version 25.0). It was considered statistically significant since a p value less than 0.05.

RESULTS

The incidence of PPD was significantly decreased both for one week and six weeks after delivery by using of esketamine (3.4% vs. 15.3%, p = 0.004 and 5.2% vs. 18.6%, p = 0.006, respectively). There were also significant differences between the stress and inflammation-related indicators in different time points in this study, while the side effects for 48 h after delivery were similar between the two groups.

CONCLUSIONS

Single intravenous injection of esketamine after delivery in participants underwent labor analgesia can decrease the occurrence of postpartum depression for one week and six weeks after delivery, while the side effects were not increased. The antidepressant effects of esketamine may be related to the reduction of stress response and inflammation.

TRIAL REGISTRATION

The trial was registered at the Chinese Clinical Trial Registry on 5/30/2022 (CTRI registration number-ChiCTR2200060387). URL of registry: https://www.chictr.org.cn/bin/home .

Esketamine Inhibits Cocaine-Seeking Behaviour Subsequent to Various Abstinence Conditions in Rats

BACKGROUND

Cocaine use disorder (CUD) is a relapsing brain disease caused by a chronic drug intake that involves neural mechanisms and psychological processes, including depression. Preclinical and clinical studies have demonstrated the promise of pharmacological drugs in controlling the reinstatement of cocaine by targeting the N-methyl-D-aspartate (NMDA) receptor. Recent evidence has revealed that esketamine, a (S) enantiomer of ketamine, shows a high affinity to NMDA receptors and has been used in clinical trials to treat moderate-to-severe depression.

METHODS

In the present paper, we investigated the effects of esketamine in regulating cocaine-seeking behaviour induced through the use of cocaine (10 mg/kg) or the cocaine-associated conditioned cue after a short (10 days)-lasting period of drug abstinence with extinction training, home cage or enrichment environment conditions in male rats. Furthermore, we investigated the acute effects of esketamine on locomotor activity in drug-naïve animals.

RESULTS

Esketamine (2.5-10 mg/kg) administered peripherally attenuated the reinstatement induced with cocaine priming or the drug-associated conditioned cue after different conditions of abstinence.

CONCLUSIONS

These results seem to support esketamine as a candidate for the pharmacological management of cocaine-seeking and relapse prevention; however, further preclinical and clinical research is needed to better clarify esketamine's actions in CUD.

Illuminating the way: the role of bright light therapy in the treatment of depression

INTRODUCTION

Despite the growing number of different therapeutic options, treatment of depression is still a challenge. A broader perspective reveals the benefits of bright light therapy (BLT). It stimulates intrinsically photosensitive retinal ganglion cells, which induces a complex cascade of events, including alterations in melatonergic, neurotrophic, GABAergic, glutamatergic, noradrenergic, serotonergic systems, and HPA axis, suggesting that BLT effects expand beyond the circadian pacemaker.

AREAS COVERED

In this review, the authors present and discuss recent data of BLT in major depressive disorder, non-seasonal depression, bipolar depression or depressive phase of bipolar disorder, and seasonal affective disorder, as well as in treatment-resistant depression (TRD). The authors further highlight BLT effects in various depressive disorders compared to placebo and report data from several studies suggesting a response to BLT in TRD. Also, the authors report data showing that BLT can be used both as a monotherapy or in combination with other pharmacological treatments.

EXPERT OPINION

BLT is an easy-to-use and low-budget therapy with good tolerability. Future studies should focus on clinical and biological predictors of response to BLT, on defining specific populations which may benefit from BLT and establishing treatment protocols regarding timing, frequency, and duration of BLT.

Therapeutic management of atypical antipsychotic‑related metabolic dysfunctions using GLP‑1 receptor agonists: A systematic review

Metabolic disorders (MDs) like obesity, dyslipidemia, and type 2 diabetes are more frequently observed in patients diagnosed with psychiatric disorders undergoing treatment with antipsychotics, particularly atypical agents, than in the general population. The second generation of antidiabetics (SGAD) has been associated with cardiovascular benefits in large clinical trials which represent an important advantage over first-generation agents and might be of interest in the psychiatric population where multiple risk factors for cardiovascular disease (e.g., smoking, lack of exercise, and lack of healthy diet) are common occurrences. Therefore, this systematic review focused on the evaluation of the glucagon-like peptide-1 receptor agonists (GLP1-RAs), as a representative of the SGAD, to determine whether these agents may be recommended in patients with psychiatric disorders and MDs. For analysis, three electronic databases and clinical trial registers were explored for papers published between January 2000 and November 2022. After applying the inclusion and exclusion criteria, 20 clinical and preclinical trials, therapeutic guidelines, and meta-analyses were reviewed, and clinical recommendations were formulated. The large majority of the reviewed data (nine papers) were graded 'moderate' based on the GRADE criteria. The efficacy and tolerability of liraglutide and exenatide in the management of antipsychotic-induced MDs were supported by evidence of average quality, while the results regarding other GLP-1RAs were not sufficient to formulate a recommendation for their administration in this specific population. Clozapine and olanzapine had the most negative consequences on body weight, glycemic, and lipid metabolism. Therefore, careful monitoring of metabolic parameters is required when these are prescribed. Liraglutide and exenatide may be recommended as augmentative agents to metformin therapy, especially in patients receiving these two atypical antipsychotics, but most of the reviewed data supported the efficacy of GLP-1RAs only during the treatment administration. The two follow-up studies retrieved in the literature reported modest effects after GLP-1RA discontinuation after 1 year; therefore, long-term monitoring of metabolic parameters is required. More research is needed, and three randomized clinical trials are already ongoing, to evaluate the effects of GLP-1RAs in decreasing body weight, but also on other important metabolic variables, such as HbA1c status, fasting glucose levels, and lipid levels in patients receiving antipsychotic treatment.

Nanosystems, Drug Molecule Functionalization and Intranasal Delivery: An Update on the Most Promising Strategies for Increasing the Therapeutic Efficacy of Antidepressant and Anxiolytic Drugs

Depression and anxiety are high incidence and debilitating psychiatric disorders, usually treated by antidepressant or anxiolytic drug administration, respectively. Nevertheless, treatment is usually given through the oral route, but the low permeability of the blood-brain barrier reduces the amount of drug that will be able to reach it, thus consequently reducing the therapeutic efficacy. Which is why it is imperative to find new solutions to make these treatments more effective, safer, and faster. To overcome this obstacle, three main strategies have been used to improve brain drug targeting: the intranasal route of administration, which allows the drug to be directly transported to the brain by neuronal pathways, bypassing the blood-brain barrier and avoiding the hepatic and gastrointestinal metabolism; the use of nanosystems for drug encapsulation, including polymeric and lipidic nanoparticles, nanometric emulsions, and nanogels; and drug molecule functionalization by ligand attachment, such as peptides and polymers. Pharmacokinetic and pharmacodynamic in vivo studies' results have shown that intranasal administration can be more efficient in brain targeting than other administration routes, and that the use of nanoformulations and drug functionalization can be quite advantageous in increasing brain-drug bioavailability. These strategies could be the key to future improved therapies for depressive and anxiety disorders.