The future of psychopharmacology: a critical appraisal of ongoing phase 2/3 trials, and of some current trends aiming to de-risk trial programmes of novel agents

Efficacy and safety of evenamide, a glutamate modulator, added to a second-generation antipsychotic in inadequately/poorly responding patients with chronic schizophrenia: Results from a randomized, double-blind, placebo-controlled, phase 3, international clinical trial

BACKGROUND

Evenamide, a glutamate modulator, is currently in phase 3 of development as add-on treatment to antipsychotics in patients with inadequate response or treatment-resistant schizophrenia. This study was designed to determine if patients with chronic schizophrenia inadequately responding to a second-generation antipsychotic would benefit from add-on treatment with evenamide at a dose of 30 mg bid.

METHODS

Study 008A was a prospective, 4-week, randomized, double-blind, placebo-controlled study evaluating the safety, tolerability, and efficacy of oral doses of evenamide of 30 mg bid in patients with chronic schizophrenia treated at stable therapeutic doses of a second-generation antipsychotic. Outpatients aged ≥18 years, both males and females, with a diagnosis of schizophrenia (DSM-V), who had been receiving antipsychotics for at least 2 years at stable doses, but still symptomatic (PANSS 70-85, CGI-S 4-6, predominant positive symptoms), were eligible for the study. Patients were randomised equally to evenamide 30 mg or placebo, given bid, after completing a 21-day screening period. The primary outcome (change from baseline in PANSS total score) was assessed weekly, with the primary endpoint at 4 weeks.

RESULTS

A total of 291 patients were enrolled, of which 11 (3·8%) discontinued prematurely, overall. Add-on treatment with evenamide was associated to a statistically significant (the absolute difference of the two treatment groups for the PANSS Total at Day 29, primary efficacy endpoint, was = 2·5 [p-value<0.05] that is associated with a Cohen's d effect size = 0·33) and clinically meaningful benefit compared to placebo across all efficacy measures, and was well tolerated.

CONCLUSION

The demonstration of statistically significant and clinically meaningful benefit of evenamide, a glutamate modulator, as add-on treatment in patients with chronic schizophrenia inadequately responding to their second-generation antipsychotic may represent a new treatment paradigm for this population.

Continuous Dopamine D2 Receptor Blockade and Long-Term Outcome in First-Episode Schizophrenia

OBJECTIVE

It is not known what proportion of patients experience relapse in first-episode schizophrenia despite continuous dopamine D2 receptor blockade and whether breakthrough psychosis is attributable to long-term use of D2-blocking antipsychotics. Using data from a Finnish nationwide cohort, the authors sought to test the hypothesis that the incidence of breakthrough psychosis is accelerated among previously relapse-free patients receiving continuous D2 antagonist treatment beyond 5 years.

METHODS

All persons age 45 years or younger with first-episode schizophrenia were identified from the nationwide registry of inpatient care for the years 1996-2014. The primary outcome was a severe relapse leading to hospitalization among those treated continuously with long-acting injectable (LAI) antipsychotics. The secondary outcome was the incidence rate ratio (IRR) of relapse during years 2-10, using year 1 as the reference.

RESULTS

A total of 305 patients initiated ensured LAI use during the first 30 days of follow-up. Kaplan-Meier analysis showed that during the 10-year follow-up, their cumulative probability of relapse was 45% (95% CI=35-57). The annual relapse incidence per person-year decreased from 0.26 (95% CI=0.20-0.35) during the first year to 0.05 (95% CI=0.01-0.19) during the fifth year, corresponding to an IRR of 0.18 (95% CI=0.04-0.74). During years 6-10, only four relapses occurred during 128 person-years, corresponding to an IRR of 0.12 (95% CI=0.03-0.33) compared with year 1.

CONCLUSIONS

About 40%-50% of patients with first-episode schizophrenia will relapse despite continuous D2 blockade, apparently due to non-dopaminergic elements of the pathophysiology of the illness, as the results show that long-term dopamine receptor blockade is not associated with an increased risk of breakthrough psychosis.

Seltorexant for major depressive disorder

INTRODUCTION

Preclinical and clinical pharmacologic evidence indicates that orexin systems are relevant to sleep-wake cycle regulation and dimensions of reward and cognition, providing the basis for hypothesizing that they may be effective as therapeutics in mental disorders. Due to the limited efficacy and tolerability profiles of existing treatments for Major Depressive Disorder (MDD), investigational compounds in novel treatment classes are needed; seltorexant, an orexin receptor antagonist, is a potential new treatment currently under investigation.

AREAS COVERED

Mechanisms implicated in MDD, including reward and sleep, are first overviewed. Then, the safety, tolerability, and efficacy profiles of seltorexant and the wider context of orexin receptor antagonism for depression are discussed in focus. Preclinical and clinical data are also discussed. PubMed, Medline, Cochrane Library, Embase, Scopus, and Web of Science were systematically searched from inception to 10 October 2024, in accordance with PRISMA guidelines.

EXPERT OPINION

Early clinical evidence suggests that seltorexant is effective in treating MDD, both in individuals diagnosed with insomnia and those not, although greater antidepressant effects are observed in individuals with severe sleep disturbance. Results from large phase III clinical trials are needed to confirm efficacy and safety.

Nutraceuticals and phytoceuticals in the treatment of schizophrenia: a systematic review and network meta-analysis "Nutra NMA SCZ"

Sub-optimal response in schizophrenia is frequent, warranting augmentation strategies over treatment-as-usual (TAU). We assessed nutraceuticals/phytoceutical augmentation strategies via network meta-analysis. Randomized controlled trials in schizophrenia/schizoaffective disorder were identified via the following databases: PubMed, MEDLINE, EMBASE, Scopus, PsycINFO, CENTRAL, and ClinicalTrials.gov. Change (Standardized Mean Difference = SMD) in total symptomatology and acceptability (Risk Ratio = RR) were co-primary outcomes. Secondary outcomes were positive, negative, cognitive, and depressive symptom changes, general psychopathology, tolerability, and response rates. We conducted subset analyses by disease phase and sensitivity analyses by risk of bias and assessed global/local inconsistency, publication bias, risk of bias, and confidence in the evidence. The systematic review included 49 records documenting 50 studies (n = 2384) documenting 22 interventions. Citicoline (SMD =-1.05,95%CI = -1.85; -0.24), L-lysine (SMD = -1.04,95%CI = -1.84; -0.25), N-acetylcysteine (SMD = -0.87, 95%CI = -1.27; -0.47) and sarcosine (SMD = -0.5,95%CI = -0.87-0.13) outperformed placebo for total symptomatology. High heterogeneity (tau2 = 0.10, I2 = 55.9%) and global inconsistency (Q = 40.79, df = 18, p = 0.002) emerged without publication bias (Egger's test, p = 0.42). Sarcosine improved negative symptoms (SMD = -0.65, 95%CI = -1.10; -0.19). N-acetylcysteine improved negative symptoms (SMD = -0.90, 95%CI = -1.42; -0.39)/general psychopathology (SMD = -0.76, 95%CI = -1.39; -0.13). No compound improved total symptomatology within acute phase studies (k = 7, n = 422). Sarcosine (SMD = -1.26,95%CI = -1.91; -0.60), citicoline (SMD = -1.05,95%CI = -1.65;-0.44), and N-acetylcysteine (SMD = -0.55,95%CI = -0.92,-0.19) outperformed placebo augmentation in clinically stable participants. Sensitivity analyses removing high-risk-of-bias studies confirmed overall findings in all phases and clinically stable samples. In contrast, the acute phase analysis restricted to low risk-of-bias studies showed a superior effect vs. placebo for N-acetylcysteine (SMD = -1.10, 95%CI = -1.75,-0.45), L-lysine (SMD = -1.05,95%CI = -1.55, -0.19), omega-3 fatty acids (SMD = -0.83,95%CI = -1.31, -0.34) and withania somnifera (SMD = -0.71,95%CI = -1.21,-0.22). Citicoline (SMD = -1.05,95%CI = -1.86,-0.23), L-lysine (SMD = -1.04,95%CI = -1.84,-0.24), N-acetylcysteine (SMD = -0.89,95%CI = -1.35,-0.43) and sarcosine (SMD = -0.61,95%CI = -1.02,-0.21) outperformed placebo augmentation of TAU ("any phase"). Drop-out due to any cause or adverse events did not differ between nutraceutical/phytoceutical vs. placebo+TAU. Sarcosine, citicoline, and N-acetylcysteine are promising augmentation interventions in stable patients with schizophrenia, yet the quality of evidence is low to very low. Further high-quality trials in acute phases/specific outcomes/difficult-to-treat schizophrenia are warranted.

Improving the physical health of overweight/obese people suffering from severe mental disorders: What is the role of antipsychotic drugs and of lifestyle psychosocial interventions?

People with severe mental disorders experience premature mortality compared with the general population. Several factors contribute to the mortality gap, including the adoption of unhealthy lifestyle behaviours, poor screening for physical illnesses, difficulties in accessing healthcare facilities, specific clinical features of mental disorders and some pharmacological treatment such as antipsychotic medications with serious metabolic side effects. In the present study, carried out in the framework of the LIFESTYLE trial, a funded nationwide multicentric study, we aimed to assess the impact of different antipsychotics in mediating the effectiveness of psychosocial intervention on healthy lifestyle behaviours. The antipsychotics have been grouped in metabolically more problematic (MMP) vs. metabolically less problematic (MLP). The final sample consists of 401 participants with a mean age of 45.6 ± 11.8 years, mainly female (57.1%), suffering from bipolar disorder (43.4%), schizophrenia spectrum disorders (29.7%) and depressive disorders (26.9%). 36.2% of patients (N = 145) received MMP antipsychotics, 32.2% were treated with MLP antipsychotics and 31.6% did not take any antipsychotic medication, but were treated with antidepressants, mood stabilizers and/or benzodiazepines. At 6-month follow-up, patients receiving the experimental lifestyle intervention and treated with MLP medication reported a significant reduction in BMI (p < .05). Our findings clearly indicate that a multilevel, personalized and individualized therapeutic approach for the treatment of patients with severe mental disorders is needed, with the involvement of different physicians and health providers for an appropriate long-term management of patients with severe mental disorders.

Knowing is Half the Battle: The Factors Leading to Efficient Recruitment of Representative Samples in Schizophrenia Research

BACKGROUND AND OBJECTIVES

Drug development in schizophrenia is limited by the differential scaling of the active treatment and placebo arms of a study, such that, as the number of sites increases, the magnitude of placebo response disproportionately increases. The objective of this article was to identify factors conducive to efficient recruitment as a step towards trial designs allowing recruitment of more participants per site, leading to reduced variability, and potentially a smaller placebo effect.

PATIENTS AND METHODS

Using the information of 554 individuals, we calculated the percentage of individuals who were screened, consented, and retained in our research, along with rationale for nonconsent. Independent t tests and Chi-squared tests were performed to compare participant characteristics.

RESULTS

Out of the 273 individuals who were fully screened, 84 did not progress to the consented stage owing to various reasons, leading to a total of 189 individuals who were screened and consented and a total of 365 individuals who were either incompletely screened or not consented into a study. Individuals with an externally validated medical history showed the highest yield in being consented and retained in research as new participants. In particular, chart reviews from clinics were highly efficient (25.8%) in facilitating new participants' enrollment, even when these individuals were not actively/prospectively seeking research. The most common reason for nonconsent was difficulty in telephone or email contact. Consenting and nonconsenting participants were similar in demographics, and recruitment sources only differed in their reported substance use.

CONCLUSIONS

Referrals and chart reviews from known clinics were the most efficient method in retaining new participants, highlighting the importance of external validation and communication between research and clinical staff within a system. Consenting participants showed no significant differences from the database as a whole, demonstrating that the study samples were representative. Future studies should aim to confirm the present findings at other academic and commercial research centers.

Effectiveness of a social cognition remediation intervention for patients with schizophrenia: a randomized-controlled study

This randomized-controlled study evaluates the effectiveness of a newly developed social cognition rehabilitation intervention, the modified Social Cognition Individualized Activity Lab (mSoCIAL), in improving social cognition and clinical and functional outcomes of persons with schizophrenia recruited in two Italian sites: University of Campania "Luigi Vanvitelli" in Naples and ASST Fatebenefratelli-Sacco in Milan. mSoCIAL consists of a social cognitive training module focusing on different domains of social cognition and of a narrative enhancement module. We assessed changes in social cognition, clinical characteristics and functional variables in patients with schizophrenia who participated in 10 weekly sessions of mSoCIAL or received treatment as usual (TAU). A paired-sample t test and a repeated-measures MANOVA were used to investigate respectively within and between-group differences. Twenty people with schizophrenia were blindly assigned to mSoCIAL and 20 to TAU. After 10 weeks, mSoCIAL significantly improved disorganization, emotion recognition, functional capacity and real-life functioning. As compared to TAU, the mSoCIAL group showed a significant improvement in minimal and enriched social inference domain of theory of mind, and in key domains of real-life functioning (interpersonal relationships, everyday life skills, and work skills). mSoCIAL improved social cognition and real-life functioning of people with schizophrenia. These results highlight the importance of social cognition deficit treatment in schizophrenia and the necessity for these interventions to be multifaced and personalized. Such an approach ensures that improvements in social cognition translate into enhanced functional outcomes.Trial registration NCT05130853, registered on 24 November 2021.

Triangulating evidence from the GALENOS living systematic review on trace amine-associated receptor 1 (TAAR1) agonists in psychosis

BACKGROUND

Trace amine-associated receptor 1 (TAAR1) agonists offer a new approach, but there is uncertainty regarding their effects, exact mechanism of action and potential role in treating psychosis.

AIMS

To evaluate the available evidence on TAAR1 agonists in psychosis, using triangulation of the output of living systematic reviews (LSRs) of animal and human studies, and provide recommendations for future research prioritisation.

METHOD

This study is part of GALENOS (Global Alliance for Living Evidence on aNxiety, depressiOn and pSychosis). In the triangulation process, a multidisciplinary group of experts, including those with lived experience, met and appraised the first co-produced living systematic reviews from GALENOS, on TAAR1 agonists.

RESULTS

The animal data suggested a potential antipsychotic effect, as TAAR1 agonists reduced locomotor activity induced by pro-psychotic drug treatment. Human studies showed few differences for ulotaront and ralmitaront compared with placebo in improving overall symptoms in adults with acute schizophrenia (four studies, n = 1291 participants, standardised mean difference (SMD) 0.15, 95% CI -0.05 to 0.34). Large placebo responses were seen in ulotaront phase three trials. Ralmitaront was less efficacious than risperidone (one study, n = 156 participants, SMD = -0.53, 95% CI -0.86 to -0.20). The side-effect profile of TAAR1 agonists was favourable compared with existing antipsychotics. Priorities for future studies included (a) using different animal models of psychosis with greater translational validity; (b) animal and human studies with wider outcomes including cognitive and affective symptoms and (c) mechanistic studies and investigations of other potential applications, such as adjunctive treatments and long-term outcomes. Recommendations for future iterations of the LSRs included (a) meta-analysis of individual human participant data, (b) including studies that used different methodologies and (c) assessing other disorders and symptoms.

CONCLUSIONS

This co-produced, international triangulation examined the available evidence and developed recommendations for future research and clinical applications for TAAR1 agonists in psychosis. Broader challenges included difficulties in assessing the risk of bias, reproducibility, translation and interpretability of animal models to clinical outcomes, and a lack of individual and clinical characteristics in the human data. The research will inform a separate, independent prioritisation process, led by lived experience experts, to prioritise directions for future research.

Spermidine alleviates depression via control of the stress response

Depression is a stress-associated disorder, and it represents a major global health issue. Its pathophysiology is complex and remains insufficiently understood, with current medications often showing limited efficacy and undesirable side effects. Here, we identify imbalanced polyamine levels and dysregulated autophagy as key components of the acute stress response in humans, and as hallmarks of chronic stress and depressive disorders. Moreover, conventional antidepressant pharmacotherapy increases endogenous plasma concentrations of the polyamine spermidine exclusively in patients who respond to the treatment, suggesting a link between spermidine and successful outcomes. In a clinical trial, involving drug-naive depressed individuals, three weeks of spermidine supplementation increased autophagy and alleviated symptoms of depression. Behavioral and mechanistic findings of spermidine supplementation were validated in various mouse stress and depression models. In summary, spermidine supplementation mitigates polyamine dysregulation and stimulates autophagy under pathological stress conditions, offering a novel and well-tolerated treatment approach for stress-related depressive disorders.

Prevalence, correlates, tolerability-related outcomes, and efficacy-related outcomes of antipsychotic polypharmacy: a systematic review and meta-analysis

BACKGROUND

Antipsychotic polypharmacy remains a clinical reality, despite an increased risk of adverse events and little evidence of additional efficacy compared with antipsychotic monotherapy. In this systematic review and meta-analysis, we aimed to provide a comprehensive assessment of antipsychotic polypharmacy prevalence, trends, and correlates across mental disorders.

METHODS

We searched MEDLINE and Embase from Jan 1, 2009 to April 30, 2024, for any original study (observational and interventional) reporting antipsychotic polypharmacy prevalence in populations with mental disorders or use of antipsychotics, regardless of age or diagnosis. Relevant studies before May 1, 2009, were identified from two previous systematic reviews of antipsychotic polypharmacy prevalence. Pooled antipsychotic polypharmacy prevalence was estimated using random-effects meta-analysis. Using subgroup and mixed-effects meta-regression analyses, we sought to identify relevant correlates of antipsychotic polypharmacy. People with lived experience were not involved in the project. This review is registered with PROSPERO (CRD42022329953).

FINDINGS

We analysed 517 studies with 599 individual timepoints reporting on 4 459 149 individuals (mean age 39·5 years [range 6·4-86·3]; data on sex and ethnicity were infrequently reported). Most studies included patients with schizophrenia spectrum disorders (SSDs; k=270, 52%). Overall, 24·8% (95% CI 22·9-26·7) of the populations received antipsychotic polypharmacy, ranging from 33·2% (30·6-36·0) in people with SSDs to 5·2% (4·0-6·8) in people with dementia. Antipsychotic polypharmacy prevalence varied by region from 15·4% (95% CI 12·9-18·2) in North America to 38·6% (27·7-50·6) in Africa. Overall antipsychotic polypharmacy prevalence increased significantly from 1970 to 2023 (β=0·019, 95% CI 0·009-0·029; p=0·0002) and was higher in adults than in children and adolescents (27·4%, 95% CI 25·2-29·8 vs 7·0%, 4·7-10·3; p<0·0001) and among inpatients than among outpatients (31·4%, 27·9-35·2 vs 19·9%, 16·8-23·3; p<0·0001). Compared with antipsychotic monotherapy, antipsychotic polypharmacy was associated with an increased risk of relapse (relative risk [RR] 1·42, 95% CI 1·04-1·93; p=0·028), psychiatric hospitalisation (1·24, 1·12-1·38; p<0·0001), worse global functioning (standardised mean difference [SMD] -0·31, 95% CI -0·44 to -0·19; p<0·0001), and more adverse events, including extrapyramidal symptoms (RR 1·63, 95% CI 1·13-2·36; p=0·0098), dystonia (5·91, 1·20-29·17; p=0·029), anticholinergic use (1·91, 1·55-2·35; p<0·0001), higher side-effect scores (SMD 0·33, 95% CI 0·24-0·42; p<0·0001), longer corrected QT interval (0·24, 0·23-0·26; p<0·0001), and greater all-cause mortality risk (RR 1·19, 95% CI 1·00-1·41; p=0·047).

INTERPRETATION

The prevalence of antipsychotic polypharmacy has increased globally over the past 50 years and is particularly high in patients with SSDs. Prescription of antipsychotic polypharmacy is associated with greater illness severity and poorer outcomes than is antipsychotic monopharmacy but does not resolve these issues. Furthermore, antipsychotic polypharmacy is associated with higher side-effect burden, including all-cause mortality.

FUNDING

None.

Placebo effects in randomized trials of pharmacological and neurostimulation interventions for mental disorders: An umbrella review

There is a growing literature exploring the placebo response within specific mental disorders, but no overarching quantitative synthesis of this research has analyzed evidence across mental disorders. We carried out an umbrella review of meta-analyses of randomized controlled trials (RCTs) of biological treatments (pharmacotherapy or neurostimulation) for mental disorders. We explored whether placebo effect size differs across distinct disorders, and the correlates of increased placebo effects. Based on a pre-registered protocol, we searched Medline, PsycInfo, EMBASE, and Web of Knowledge up to 23.10.2022 for systematic reviews and/or meta-analyses reporting placebo effect sizes in psychopharmacological or neurostimulation RCTs. Twenty meta-analyses, summarising 1,691 RCTs involving 261,730 patients, were included. Placebo effect size varied, and was large in alcohol use disorder (g = 0.90, 95% CI [0.70, 1.09]), depression (g = 1.10, 95% CI [1.06, 1.15]), restless legs syndrome (g = 1.41, 95% CI [1.25, 1.56]), and generalized anxiety disorder (d = 1.85, 95% CI [1.61, 2.09]). Placebo effect size was small-to-medium in obsessive-compulsive disorder (d = 0.32, 95% CI [0.22, 0.41]), primary insomnia (g = 0.35, 95% CI [0.28, 0.42]), and schizophrenia spectrum disorders (standardized mean change = 0.33, 95% CI [0.22, 0.44]). Correlates of larger placebo response in multiple mental disorders included later publication year (opposite finding for ADHD), younger age, more trial sites, larger sample size, increased baseline severity, and larger active treatment effect size. Most (18 of 20) meta-analyses were judged 'low' quality as per AMSTAR-2. Placebo effect sizes varied substantially across mental disorders. Future research should explore the sources of this variation. We identified important gaps in the literature, with no eligible systematic reviews/meta-analyses of placebo response in stress-related disorders, eating disorders, behavioural addictions, or bipolar mania.

N-methyl-D-aspartate Receptors and Depression: Linking Psychopharmacology, Pathology and Physiology in a Unifying Hypothesis for the Epigenetic Code of Neural Plasticity

Uncompetitive NMDAR (N-methyl-D-aspartate receptor) antagonists restore impaired neural plasticity, reverse depressive-like behavior in animal models, and relieve major depressive disorder (MDD) in humans. This review integrates recent findings from in silico, in vitro, in vivo, and human studies of uncompetitive NMDAR antagonists into the extensive body of knowledge on NMDARs and neural plasticity. Uncompetitive NMDAR antagonists are activity-dependent channel blockers that preferentially target hyperactive GluN2D subtypes because these subtypes are most sensitive to activation by low concentrations of extracellular glutamate and are more likely activated by certain pathological agonists and allosteric modulators. Hyperactivity of GluN2D subtypes in specific neural circuits may underlie the pathophysiology of MDD. We hypothesize that neural plasticity is epigenetically regulated by precise Ca2+ quanta entering cells via NMDARs. Stimuli reach receptor cells (specialized cells that detect specific types of stimuli and convert them into electrical signals) and change their membrane potential, regulating glutamate release in the synaptic cleft. Free glutamate binds ionotropic glutamatergic receptors regulating NMDAR-mediated Ca2+ influx. Quanta of Ca2+ via NMDARs activate enzymatic pathways, epigenetically regulating synaptic protein homeostasis and synaptic receptor expression; thereby, Ca2+ quanta via NMDARs control the balance between long-term potentiation and long-term depression. This NMDAR Ca2+ quantal hypothesis for the epigenetic code of neural plasticity integrates recent psychopharmacology findings into established physiological and pathological mechanisms of brain function.

Systematic Review and Meta-Analysis: Placebo Response in Randomized Controlled Trials of Tourette's Disorder Medications

OBJECTIVE

To examine the magnitude of placebo response in randomized controlled trials (RCTs) of medications for Tourette's disorder.

METHOD

CENTRAL, Embase, PubMed, PsycInfo, Web of Science, WHO ICTRP, and ClinicalTrials.gov databases were searched up to September, 2023 to identify placebo-controlled RCTs assessing pharmacological interventions for Tourette's disorder. Standardized mean change and standardized mean difference were calculated for within-group (placebo, drug) and between-group (drug-placebo) change in tics. Data were pooled in random-effects meta-analysis. Meta-regressions were performed to identify study-level characteristics that could be differentially associated with placebo, drug, and drug-placebo response.

RESULTS

Literature searches identified 13,775 records, and 50 RCTs involving 1,566 participants were included in the placebo meta-analysis. Placebo response was medium to large (standardized mean change: -0.62; 95% CI: -0.75, -0.5; I2 = 76%; τ2 = 0.14). Several factors were associated with larger placebo responses (eg, non-US RCT, industry sponsorship, number of centers and participants). However, there was a moderate-to-high correlation between placebo and drug response (ρ = 0.66; 95% CI: 0.47, 0.79), and factors associated with larger placebo response were also generally associated with larger drug responses. There was not a significant correlation between placebo response and drug-placebo differences (ρ = -0.05; 95% CI: -0.32, 0.22), and factors associated with larger placebo response generally did not interfere in drug-placebo differences.

CONCLUSION

The magnitude of placebo response in Tourette's disorder may be large, but similar to that in other child and adolescent psychiatric conditions. Clinical researchers may manipulate study-level factors to diminish placebo response (eg, carefully selecting study sites and keeping them at the minimum feasibility). However, drug-placebo differences may not increase as drug response will likely diminish as well.

STUDY PREREGISTRATION INFORMATION

Comparative Efficacy, Tolerability, and Acceptability of Pharmacological Interventions for Chronic Tic Disorders Including Tourette's Syndrome in Children, Adolescents, and Adults: Protocol for a Systematic Review and Network Meta-analysis; https://www.crd.york.ac.uk; CRD42022296975.

DIVERSITY & INCLUSION STATEMENT

One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented sexual and/or gender groups in science. One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented racial and/or ethnic groups in science.

Muscarinic Receptor Activators as Novel Treatments for Schizophrenia

Achieving optimal treatment outcomes for individuals living with schizophrenia remains challenging, despite 70 years of drug development efforts. Many chemically distinct antipsychotics have been developed over the past 7 decades with improved safety and tolerability but with only slight variation in efficacy. All antipsychotics currently approved for the treatment of schizophrenia act as antagonists or partial agonists at the dopamine D2 receptor. With only a few possible exceptions, antipsychotic drugs have similar and modest efficacy for treating positive symptoms and are relatively ineffective in addressing the negative and cognitive symptoms of the disease. The development of novel treatments focused on targeting muscarinic acetylcholine receptors (mAChRs) has been of interest for more than 25 years following reports that treatment with a dual M1/M4-preferring mAChR agonist resulted in antipsychotic-like effects and procognitive properties in individuals living with Alzheimer's disease and schizophrenia; more recent clinical trials have confirmed these findings. In addition, advances in our understanding of the receptor binding and activation properties of xanomeline at specific mAChRs have the potential to inform future drug design targeting mAChRs.

Schizophrenia Interactome-Derived Repurposable Drugs and Randomized Controlled Trials of Two Candidates

There is a substantial unmet need for effective and patient-acceptable drugs to treat severe mental illnesses such as schizophrenia (SZ). Computational analysis of genomic, transcriptomic, and pharmacologic data generated in the past 2 decades enables repurposing of drugs or compounds with acceptable safety profiles, namely those that are U.S. Food and Drug Administration approved or have reached late stages in clinical trials. We developed a rational approach to achieve this computationally for SZ by studying drugs that target the proteins in its protein interaction network (interactome). This involved contrasting the transcriptomic modulations observed in the disorder and the drug; our analyses resulted in 12 candidate drugs, 9 of which had additional supportive evidence whereby their target networks were enriched for pathways relevant to SZ etiology or for genes that had an association with diseases pathogenically similar to SZ. To translate these computational results to the clinic, these shortlisted drugs must be tested empirically through randomized controlled trials, in which their previous safety approvals obviate the need for time-consuming phase 1 and 2 studies. We selected 2 among the shortlisted candidates based on likely adherence and side-effect profiles. We are testing them through adjunctive randomized controlled trials for patients with SZ or schizoaffective disorder who experienced incomplete resolution of psychotic features with conventional treatment. The integrated computational analysis for identifying and ranking drugs for clinical trials can be iterated as additional data are obtained. Our approach could be expanded to enable disease subtype-specific drug discovery in the future and should also be exploited for other psychiatric disorders.

New Drug Treatments for Schizophrenia: A Review of Approaches to Target Circuit Dysfunction

Schizophrenia is a leading cause of global disease burden. Current drug treatments are associated with significant side effects and have limited efficacy for many patients, highlighting the need to develop new approaches that target other aspects of the neurobiology of schizophrenia. Preclinical, in vivo imaging, postmortem, genetic, and pharmacological studies have highlighted the key role of cortical GABAergic (gamma-aminobutyric acidergic)-glutamatergic microcircuits and their projections to subcortical dopaminergic circuits in the pathoetiology of negative, cognitive, and psychotic symptoms. Antipsychotics primarily act downstream of the dopaminergic component of this circuit. However, multiple drugs are currently in development that could target other elements of this circuit to treat schizophrenia. These include drugs for GABAergic or glutamatergic targets, including glycine transporters, D-amino acid oxidase, sodium channels, or potassium channels. Other drugs in development are likely to primarily act on pathways that regulate the dopaminergic system, such as muscarinic or trace amine receptors or 5-HT2A receptors, while PDE10A inhibitors are being developed to modulate the downstream consequences of dopaminergic dysfunction. Our review considers where new drugs may act on this circuit and their latest clinical trial evidence in terms of indication, efficacy, and side effects. Limitations of the circuit model, including whether there are neurobiologically distinct subgroups of patients, and future directions are also considered. Several drugs based on the mechanisms reviewed have promising clinical data, with the muscarinic agonist KarXT most advanced. If these drugs are approved for clinical use, they have the potential to revolutionize understanding of the pathophysiology and treatment of schizophrenia.

Risk factors, prevention and treatment of weight gain associated with the use of antidepressants and antipsychotics: a state-of-the-art clinical review

INTRODUCTION

People with severe mental illness have poor cardiometabolic health. Commonly used antidepressants and antipsychotics frequently lead to weight gain, which may further contribute to adverse cardiovascular outcomes.

AREAS COVERED

We searched MEDLINE up to April 2023 for umbrella reviews, (network-)meta-analyses, trials and cohort studies on risk factors, prevention and treatment strategies of weight gain associated with antidepressants/antipsychotics. We developed 10 clinical recommendations.

EXPERT OPINION

To prevent, manage, and treat antidepressant/antipsychotic-related weight gain, we recommend i) assessing risk factors for obesity before treatment, ii) monitoring metabolic health at baseline and regularly during follow-up, iii) offering lifestyle interventions including regular exercise and healthy diet based on patient preference to optimize motivation, iv) considering first-line psychotherapy for mild-moderate depression and anxiety disorders, v)choosing medications based on medications' and patient's weight gain risk, vi) choosing medications based on acute vs long-term treatment, vii) using effective, tolerated medications, viii) switching to less weight-inducing antipsychotics/antidepressants where possible, ix) using early weight gain as a predictor of further weight gain to inform the timing of intervention/switch options, and x) considering adding metformin or glucagon-like peptide-1 receptor agonists, or topiramate(second-line due to potential adverse cognitive effects) to antipsychotics, or aripiprazole to clozapine or olanzapine.

Conceptualization and characterization of "primary" and "secondary" cognitive impairment in schizophrenia

Cognitive impairment represents one of the core features of schizophrenia, involves both neurocognition and social cognition domains, and has a significant negative impact on real-world functioning. The present review provides a framework for the conceptualization and characterization of "primary" and "secondary" cognitive impairment in schizophrenia. In this conceptualization, primary cognitive impairment can be defined as a consequence of the neurobiological alterations that underlie psychopathological manifestations of the disorder, while secondary cognitive impairment can be defined as the results of a source issue that has a negative impact on cognitive performance. Sources of secondary cognitive impairment are frequent in people with schizophrenia and include several different factors, such as positive and negative symptoms, depressive symptoms, autistic symptoms, pharmacotherapy, substance abuse, metabolic syndrome, social deprivation, and sleep disorders. It can be hypothesized that secondary cognitive impairment may be improved by effectively resolving the source issue, while primary cognitive impairment may benefit from dedicated treatment. Further research is required to confirm this hypothesis, to better characterize the distinction between primary and secondary cognitive impairment in a clinical and in a neurobiological perspective, and to evaluate the impact of systematically assessing and treating secondary cognitive impairment.

The excitatory-inhibitory balance as a target for the development of novel drugs to treat schizophrenia

The intricate balance between excitation and inhibition (E/I) in the brain plays a crucial role in normative information processing. Dysfunctions in the E/I balance have been implicated in various psychiatric disorders, including schizophrenia (SCZ). In particular, abnormalities in GABAergic signaling, specifically in parvalbumin (PV)-containing interneurons, have been consistently observed in SCZ pathophysiology. PV interneuron function is vital for maintaining an ideal E/I balance, and alterations in PV interneuron-mediated inhibition contribute to circuit deficits observed in SCZ, including hippocampus hyperactivity and midbrain dopamine system overdrive. While current antipsychotic medications primarily target D2 dopamine receptors and are effective primarily in treating positive symptoms, novel therapeutic strategies aiming to restore the E/I balance could potentially mitigate not only positive symptoms but also negative symptoms and cognitive deficits. This could involve, for instance, increasing the inhibitory drive onto excitatory neurons or decreasing the putative enhanced pyramidal neuron activity due to functional loss of PV interneurons. Compounds targeting the glycine site at glutamate NMDA receptors and muscarinic acetylcholine receptors on PV interneurons that can increase PV interneuron drive, as well as drugs that increase the postsynaptic action of GABA, such as positive allosteric modulators of α5-GABA-A receptors, and decrease glutamatergic output, such as mGluR2/3 agonists, represent promising approaches. Preventive strategies aiming at E/I balance also represent a path to reduce the risk of transitioning to SCZ in high-risk individuals. Therefore, compounds with novel mechanisms targeting E/I balance provide optimism for more effective and tailored interventions in the management of SCZ.

Aticaprant: (a κ-opioid receptor antagonist) for major depressive disorder

INTRODUCTION

Major depression is a common, disabling mental health condition associated with the highest disease burden for any neuropsychiatric disorder worldwide, according to the WHO. Due to the imperfect efficacy and tolerability profiles of existing treatments, investigational compounds in novel treatment classes are needed. Opioid-receptor antagonists are a potential new class of treatments currently under investigation.

AREAS COVERED

Major depressive disorder is first overviewed. Existing treatments, both their mechanisms of action and their place within the antidepressant space, are discussed herein. Then, the profile of Aticaprant and the wider context of kappa-opioid antagonism for depression are discussed in focus.

EXPERT OPINION

Early evidence indicates that Aticaprant may possess desirable pharmacodynamic and pharmacokinetic properties. A lack of convincing efficacy data at the time of writing precludes any definitive statement on its potential as an antidepressant.

Agomelatine efficacy in treatment resistant obsessive-compulsive disorder: A randomized controlled trial

BACKGROUND

Obsessive-compulsive disorder (OCD) is a prevalent and burdensome mental health condition, often resistant to conventional treatments. Agomelatine (Valdoxan), a compound acting on serotonin and melatonin systems, has shown promise in treating those with treatment-resistant OCD based on anecdotal reports and case studies.

METHODS

A randomized, double-blind controlled trial was conducted with 60 patients diagnosed with treatment-resistant OCD. Participants were randomized into an intervention group (receiving agomelatine 50 mg/day) and a control group (receiving placebo). OCD symptoms were assessed using the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) over a 12-week period.

RESULTS

There were no significant differences in age, gender, or baseline Y-BOCS scores between intervention and control groups. Agomelatine did not demonstrate a significant improvement in OCD symptoms compared to placebo. Adverse events were comparable between groups, and liver enzyme levels remained within the normal range.

CONCLUSION

This study, while not confirming superior efficacy compared to placebo, underscores the need for continued investigation into agomelatine's potential for treating specific subgroups of OCD patients, underscoring the need for more comprehensive and well-controlled trials in the future.

Treatments in the pipeline for attention-deficit/hyperactivity disorder (ADHD) in adults

To provide an overview of treatments in the pipeline for adults with attention-deficit/hyperactivity disorder (ADHD), we searched https://clinicaltrials.gov/and and https://www.clinicaltrialsregister.eu/ from 01/01/2010-10/18/2023 for ongoing or completed phase 2 or 3 randomised controlled trials (RCTs), assessing pharmacological or non-pharmacological interventions for adults with ADHD with no current regulatory approval. We found 90 eligible RCTs. Of these, 24 (27 %) reported results with statistical analysis for primary efficacy endpoints. While several pharmacological and non-pharmacological interventions had evidence of superiority compared to the control condition from a single RCT, centanafadine (norepinephrine, dopamine, and serotonin re-uptake inhibitor) was the only treatment with evidence of efficacy on ADHD core symptoms (small effect size=0.28-0.40) replicated in at least one additional RCT, alongside reasonable tolerability. Overall, the body of ongoing RCTs in adults with ADHD is insufficient, without any intervention on the horizon to match the efficacy of stimulant treatment or atomoxetine and with better tolerability profile. Additional effective and well tolerated treatments for adults with ADHD require development and testing.

What Remains to Be Discovered in Schizophrenia Therapeutics: Contributions by Advancing the Molecular Mechanisms of Drugs for Psychosis and Schizophrenia

Schizophrenia is a frequently debilitating and complex mental disorder affecting approximately 1% of the global population, characterized by symptoms such as hallucinations, delusions, disorganized thoughts and behaviors, cognitive dysfunction, and negative symptoms. Traditional treatment has centered on postsynaptic dopamine antagonists, commonly known as antipsychotic drugs, which aim to alleviate symptoms and improve functioning and the quality of life. Despite the availability of these medications, significant challenges remain in schizophrenia therapeutics, including incomplete symptom relief, treatment resistance, and medication side effects. This opinion article explores advancements in schizophrenia treatment, emphasizing molecular mechanisms, novel drug targets, and innovative delivery methods. One promising approach is novel strategies that target neural networks and circuits rather than single neurotransmitters, acknowledging the complexity of brain region interconnections involved in schizophrenia. Another promising approach is the development of biased agonists, which selectively activate specific signaling pathways downstream of receptors, offering potential for more precise pharmacological interventions with fewer side effects. The concept of molecular polypharmacy, where a single drug targets multiple molecular pathways, is exemplified by KarXT, a novel drug combining xanomeline and trospium to address both psychosis and cognitive dysfunction. This approach represents a comprehensive strategy for schizophrenia treatment, potentially improving outcomes for patients. In conclusion, advancing the molecular understanding of schizophrenia and exploring innovative therapeutic strategies hold promise for addressing the unmet needs in schizophrenia treatment, aiming for more effective and tailored interventions. Future research should focus on these novel approaches to achieve better clinical outcomes and improve the functional level and quality of life for individuals with schizophrenia.

Overcoming the barriers to identifying and managing treatment-resistant schizophrenia and to improving access to clozapine: A narrative review and recommendation for clinical practice

Clozapine is the only approved antipsychotic for treatment-resistant schizophrenia (TRS). Although a large body of evidence supports its efficacy and favorable risk-benefit ratio in individuals who have failed two or more antipsychotics, clozapine remains underused. However, variations in clozapine utilization across geographic and clinical settings suggest that it could be possible to improve its use. In this narrative review and expert opinion, we summarized information available in the literature on the mechanisms of action, effectiveness, and potential adverse events of clozapine. We identified barriers leading to discouragement in clozapine prescription internationally, and we proposed practical solutions to overcome each barrier. One of the main obstacles identified to the use of clozapine is the lack of appropriate training for physicians: we highlighted the need to develop specific professional programs to train clinicians, both practicing and in residency, on the relevance and efficacy of clozapine in TRS treatment, initiation, maintenance, and management of potential adverse events. This approach would facilitate physicians to identify eligible patients and offer clozapine as a treatment option in the early stage of the disease. We also noted that increasing awareness of the benefits of clozapine among healthcare professionals, people with TRS, and their caregivers can help promote the use of clozapine. Educational material, such as leaflets or videos, could be developed and distributed to achieve this goal. The information provided in this article may be useful to improve disease burden and support healthcare professionals, patients, and caregivers navigating the complex pathways to TRS management.

Efficacy and safety of long-acting injectable versus oral antipsychotics in the treatment of patients with early-phase schizophrenia-spectrum disorders: a systematic review and meta-analysis

Background

Long-acting injectable antipsychotics (LAIs) have advantages over oral antipsychotics (OAPs) in preventing relapse and hospitalization in chronically ill patients with schizophrenia-spectrum disorders (SSDs), but evidence in patients with first-episode/recent-onset, that is, early-phase-SSDs is less clear.

Objectives

To assess the relative medium- and long-term efficacy and safety of LAIs versus OAPs in the maintenance treatment of patients with early-phase SSDs.

Method

We searched major electronic databases for head-to-head randomized controlled trials (RCTs) comparing LAIs and OAPs for the maintenance treatment of patients with early-phase-SSDs.

Design

Pairwise, random-effects meta-analysis. Relapse/hospitalization and acceptability (all-cause discontinuation) measured at study-endpoint were co-primary outcomes, calculating risk ratios (RRs) with their 95% confidence intervals (CIs). Subgroup analyses sought to identify factors moderating differences in efficacy or acceptability between LAIs and OAPs.

Results

Across 11 head-to-head RCTs (n = 2374, median age = 25.2 years, males = 68.4%, median illness duration = 45.8 weeks) lasting 13-104 (median = 78) weeks, no significant differences emerged between LAIs and OAPs for relapse/hospitalization prevention (RR = 0.79, 95%CI = 0.58-1.06, p = 0.13) and acceptability (RR = 0.92, 95%CI = 0.80-1.05, p = 0.20). The included trials were highly heterogeneous regarding methodology and patient populations. LAIs outperformed OAPs in preventing relapse/hospitalization in studies with stable patients (RR = 0.65, 95%CI = 0.45-0.92), pragmatic design (RR = 0.67, 95%CI = 0.54-0.82), and strict intent-to-treat approach (RR = 0.64, 95%CI = 0.52-0.80). Furthermore, LAIs were associated with better acceptability in studies with schizophrenia patients only (RR = 0.87, 95%CI = 0.79-0.95), longer illness duration (RR = 0.88, 95%CI = 0.80-0.97), unstable patients (RR = 0.89, 95%CI = 0.81-0.99) and allowed OAP supplementation of LAIs (RR = 0.90, 95%CI = 0.81-0.99).

Conclusion

LAIs and OAPs did not differ significantly regarding relapse prevention/hospitalization and acceptability. However, in nine subgroup analyses, LAIs were superior to OAPs in patients with EP-SSDs with indicators of higher quality and/or pragmatic design regarding relapse/hospitalization prevention (four subgroup analyses) and/or reduced all-cause discontinuation (five subgroup analyses), without any instance of OAP superiority versus LAIs. More high-quality pragmatic trials comparing LAIs with OAPs in EP-SSDs are needed.

Trial registration

CRD42023407120 (PROSPERO).

New clues for the role of cerebellum in schizophrenia and the associated cognitive impairment

Schizophrenia (SZ) is a complex neuropsychiatric disorder associated with severe cognitive dysfunction. Although research has mainly focused on forebrain abnormalities, emerging results support the involvement of the cerebellum in SZ physiopathology, particularly in Cognitive Impairment Associated with SZ (CIAS). Besides its role in motor learning and control, the cerebellum is implicated in cognition and emotion. Recent research suggests that structural and functional changes in the cerebellum are linked to deficits in various cognitive domains including attention, working memory, and decision-making. Moreover, cerebellar dysfunction is related to altered cerebellar circuit activities and connectivity with brain regions associated with cognitive processing. This review delves into the role of the cerebellum in CIAS. We initially consider the major forebrain alterations in CIAS, addressing impairments in neurotransmitter systems, synaptic plasticity, and connectivity. We then focus on recent findings showing that several mechanisms are also altered in the cerebellum and that cerebellar communication with the forebrain is impaired. This evidence implicates the cerebellum as a key component of circuits underpinning CIAS physiopathology. Further studies addressing cerebellar involvement in SZ and CIAS are warranted and might open new perspectives toward understanding the physiopathology and effective treatment of these disorders.

Psychosis superspectrum II: neurobiology, treatment, and implications

Alternatives to traditional categorical diagnoses have been proposed to improve the validity and utility of psychiatric nosology. This paper continues the companion review of an alternative model, the psychosis superspectrum of the Hierarchical Taxonomy of Psychopathology (HiTOP). The superspectrum model aims to describe psychosis-related psychopathology according to data on distributions and associations among signs and symptoms. The superspectrum includes psychoticism and detachment spectra as well as narrow subdimensions within them. Auxiliary domains of cognitive deficit and functional impairment complete the psychopathology profile. The current paper reviews evidence on this model from neurobiology, treatment response, clinical utility, and measure development. Neurobiology research suggests that psychopathology included in the superspectrum shows similar patterns of neural alterations. Treatment response often mirrors the hierarchy of the superspectrum with some treatments being efficacious for psychoticism, others for detachment, and others for a specific subdimension. Compared to traditional diagnostic systems, the quantitative nosology shows an approximately 2-fold increase in reliability, explanatory power, and prognostic accuracy. Clinicians consistently report that the quantitative nosology has more utility than traditional diagnoses, but studies of patients with frank psychosis are currently lacking. Validated measures are available to implement the superspectrum model in practice. The dimensional conceptualization of psychosis-related psychopathology has implications for research, clinical practice, and public health programs. For example, it encourages use of the cohort study design (rather than case-control), transdiagnostic treatment strategies, and selective prevention based on subclinical symptoms. These approaches are already used in the field, and the superspectrum provides further impetus and guidance for their implementation. Existing knowledge on this model is substantial, but significant gaps remain. We identify outstanding questions and propose testable hypotheses to guide further research. Overall, we predict that the more informative, reliable, and valid characterization of psychopathology offered by the superspectrum model will facilitate progress in research and clinical care.

Combination of Two Long-Acting Antipsychotics in Schizophrenia Spectrum Disorders: A Systematic Review

BACKGROUND

Up to 34% of patients with schizophrenia are resistant to several treatment trials. Lack of continuous and adequate treatment is associated with relapse, rehospitalization, a lower effect of antipsychotic therapy, and higher risk of side effects. Long-acting injectables antipsychotics (LAI APs) enhance compliance and improve clinical outcomes and quality of life in patients with schizophrenia, and thus it may be advisable to administer two LAI APs at the same time in cases of treatment-resistant schizophrenia. The purpose of this review is to summarize the available literature regarding the combined use of two LAI APs in patients with schizophrenia or other psychotic spectrum disorders.

METHODS

An extensive literature search for relevant articles regarding any combination of two long-acting injectable antipsychotics has been performed from inception up to 9 February 2024, on PubMed, Scopus and APA PsycInfo, according to the PRISMA statement. Only studies reporting combination of two LAI APs and its clinical outcome in patients with schizophrenia and related disorders were selected.

RESULTS

After the selection process, nine case reports, four case series and two observational retrospective studies were included in the final analysis. All patients treated with dual LAI APs reported a good response, and no new or unexpected adverse effects due to the combination of two LAIs were reported. Different drug combinations were used, and the most frequent association resulted in aripiprazole monohydrate + paliperidone palmitate once monthly (32 times).

CONCLUSIONS

Our review highlights that the treatment regimen with two concurrent LAI APs is already widely used in clinical practice and is recognized as providing a promising, effective, and relatively safe therapeutic strategy for treating the schizophrenia spectrum disorders.

Placebo Effects Are Small on Average in the 7.5% CO2 Inhalational Model of Generalized Anxiety

BACKGROUND

Anxiety disorders are highly prevalent and socio-economically costly. Novel pharmacological treatments for these disorders are needed because many patients do not respond to current agents or experience unwanted side effects. However, a barrier to treatment development is the variable and large placebo response rate seen in trials of novel anxiolytics. Despite this, the mechanisms that drive placebo responses in anxiety disorders have been little investigated, possibly due to low availability of convenient experimental paradigms. We aimed to develop and test a novel protocol for inducing placebo anxiolysis in the 7.5% CO2 inhalational model of generalized anxiety in healthy volunteers.

METHODS

Following a baseline 20-minute CO2 challenge, 32 healthy volunteers were administered a placebo intranasal spray labelled as either the anxiolytic "lorazepam" or "saline." Following this, participants surreptitiously underwent a 20-minute inhalation of normal air. Post-conditioning, a second dose of the placebo was administered, after which participants completed another CO2 challenge.

RESULTS

Participants administered sham "lorazepam" reported significant positive expectations of reduced anxiety (P = .001), but there was no group-level placebo effect on anxiety following CO2 challenge post-conditioning (Ps > .350). Surprisingly, we found many participants exhibited unexpected worsening of anxiety, despite positive expectations.

CONCLUSIONS

Contrary to our hypothesis, our novel paradigm did not induce a placebo response, on average. It is possible that effects of 7.5% CO2 inhalation on prefrontal cortex function or behavior in line with a Bayesian predictive coding framework attenuated the effect of expectations on subsequent placebo response. Future studies are needed to explore these possibilities.

Targeting metaplasticity mechanisms to promote sustained antidepressant actions

The discovery that subanesthetic doses of (R, S)-ketamine (ketamine) and (S)-ketamine (esketamine) rapidly induce antidepressant effects and promote sustained actions following drug clearance in depressed patients who are treatment-resistant to other therapies has resulted in a paradigm shift in the conceptualization of how rapidly and effectively depression can be treated. Consequently, the mechanism(s) that next generation antidepressants may engage to improve pathophysiology and resultant symptomology are being reconceptualized. Impaired excitatory glutamatergic synapses in mood-regulating circuits are likely a substantial contributor to the pathophysiology of depression. Metaplasticity is the process of regulating future capacity for plasticity by priming neurons with a stimulation that alters later neuronal plasticity responses. Accordingly, the development of treatment modalities that specifically modulate the duration, direction, or magnitude of glutamatergic synaptic plasticity events such as long-term potentiation (LTP), defined here as metaplastogens, may be an effective approach to reverse the pathophysiology underlying depression and improve depression symptoms. We review evidence that the initiating mechanisms of pharmacologically diverse rapid-acting antidepressants (i.e., ketamine mimetics) converge on consistent downstream molecular mediators that facilitate the expression/maintenance of increased synaptic strength and resultant persisting antidepressant effects. Specifically, while the initiating mechanisms of these therapies may differ (e.g., cell type-specificity, N-methyl-D-aspartate receptor (NMDAR) subtype-selective inhibition vs activation, metabotropic glutamate receptor 2/3 antagonism, AMPA receptor potentiation, 5-HT receptor-activating psychedelics, etc.), the sustained therapeutic mechanisms of putative rapid-acting antidepressants will be mediated, in part, by metaplastic effects that converge on consistent molecular mediators to enhance excitatory neurotransmission and altered capacity for synaptic plasticity. We conclude that the convergence of these therapeutic mechanisms provides the opportunity for metaplasticity processes to be harnessed as a druggable plasticity mechanism by next-generation therapeutics. Further, targeting metaplastic mechanisms presents therapeutic advantages including decreased dosing frequency and associated diminished adverse responses by eliminating the requirement for the drug to be continuously present.

Seven decades of antipsychotic drugs: Why is the life of Australians with schizophrenia still so suboptimal?

The advent of dopamine (D2) receptor-blocking medications over 70 years ago, ushered in a new era of biological treatment for schizophrenia. However, we argue that little subsequent progress has been made in translating this into fulfilled and fulfilling lives for people with schizophrenia. This Viewpoint asks why this is the case, and suggests ways forward for capitalising on extant and emerging new treatments for psychotic disorders, to the betterment of the lives of people living with schizophrenia.

Drug targeting in psychiatric disorders - how to overcome the loss in translation?

In spite of major efforts and investment in development of psychiatric drugs, many clinical trials have failed in recent decades, and clinicians still prescribe drugs that were discovered many years ago. Although multiple reasons have been discussed for the drug development deadlock, we focus here on one of the major possible biological reasons: differences between the characteristics of drug targets in preclinical models and the corresponding targets in patients. Importantly, based on technological advances in single-cell analysis, we propose here a framework for the use of available and newly emerging knowledge from single-cell and spatial omics studies to evaluate and potentially improve the translational predictivity of preclinical models before commencing preclinical and, in particular, clinical studies. We believe that these recommendations will improve preclinical models and the ability to assess drugs in clinical trials, reducing failure rates in expensive late-stage trials and ultimately benefitting psychiatric drug discovery and development.

Current and Future Approaches to Pediatric Anxiety Disorder Treatment

This overview critically appraises the literature on the treatment of pediatric anxiety disorders. The two established treatments for these conditions comprise cognitive-behavioral therapy (CBT) and antidepressant medications. Many youths receiving these treatments fail to achieve remission, which creates a need for new treatments. After summarizing the literature on CBT and currently available medications, the authors describe research that lays a foundation for improvements in the treatment of pediatric anxiety disorders. This foundation leverages neuroscientific investigations, also described in the overview, which provide insights on mechanisms of successful treatment.

The definition of treatment resistance in anxiety disorders: a Delphi method-based consensus guideline

Anxiety disorders are very prevalent and often persistent mental disorders, with a considerable rate of treatment resistance which requires regulatory clinical trials of innovative therapeutic interventions. However, an explicit definition of treatment-resistant anxiety disorders (TR-AD) informing such trials is currently lacking. We used a Delphi method-based consensus approach to provide internationally agreed, consistent and clinically useful operational criteria for TR-AD in adults. Following a summary of the current state of knowledge based on international guidelines and an available systematic review, a survey of free-text responses to a 29-item questionnaire on relevant aspects of TR-AD, and an online consensus meeting, a panel of 36 multidisciplinary international experts and stakeholders voted anonymously on written statements in three survey rounds. Consensus was defined as ≥75% of the panel agreeing with a statement. The panel agreed on a set of 14 recommendations for the definition of TR-AD, providing detailed operational criteria for resistance to pharmacological and/or psychotherapeutic treatment, as well as a potential staging model. The panel also evaluated further aspects regarding epidemiological subgroups, comorbidities and biographical factors, the terminology of TR-AD vs. "difficult-to-treat" anxiety disorders, preferences and attitudes of persons with these disorders, and future research directions. This Delphi method-based consensus on operational criteria for TR-AD is expected to serve as a systematic, consistent and practical clinical guideline to aid in designing future mechanistic studies and facilitate clinical trials for regulatory purposes. This effort could ultimately lead to the development of more effective evidence-based stepped-care treatment algorithms for patients with anxiety disorders.

Psychopharmacology in children and adolescents: unmet needs and opportunities

Psychopharmacological treatment is an important component of the multimodal intervention approach to treating mental health conditions in children and adolescents. Currently, there are many unmet needs but also opportunities, alongside possible risks to consider, regarding the pharmacological treatment of mental health conditions in children and adolescents. In this Position Paper, we highlight and address these unmet needs and opportunities, including the perspectives of clinicians and researchers from the European College of Neuropsychopharmacology-Child and Adolescent Network, alongside those of experts by lived experience from national and international associations, via a survey involving 644 participants from 13 countries, and of regulators, through representation from the European Medicines Agency. We present and discuss the evidence base for medications currently used for mental disorders in children and adolescents, medications in the pipeline, opportunities in the development of novel medications, crucial priorities for the conduct of future clinical studies, challenges and opportunities in terms of the regulatory and legislative framework, and innovations in the way research is conducted, reported, and promoted.

Nutraceuticals and phytoceuticals in the treatment of schizophrenia: a systematic review and network meta-analysis

Background

Sub-optimal response in schizophrenia is frequent, warranting augmentation strategies over treatment-as-usual (TAU).

Methods

We assessed nutraceuticals/phytoceutical augmentation strategies via network meta-analysis. Randomized controlled trials in schizophrenia/schizoaffective disorder were identified via the following databases: PubMed, MEDLINE, EMBASE, Scopus, PsycINFO, CENTRAL, and ClinicalTrials.gov. Change (Standardized Mean Difference=SMD) in total symptomatology and acceptability (Risk Ratio=RR) were co-primary outcomes. Secondary outcomes were positive, negative, cognitive, and depressive symptom changes, general psychopathology, tolerability, and response rates. We conducted subset analyses by disease phase and sensitivity analyses by risk of bias and assessed global/local inconsistency, publication bias, risk of bias, and confidence in the evidence.

Results

The systematic review included 49 records documenting 50 studies (n=2,384) documenting 22 interventions. Citicoline (SMD=-1.05,95%CI=-1.85; -.24), L-lysine (SMD=-1.04,95%CI=-1.84;-.25), N-acetylcysteine (SMD=-.87,95%CI=-1.27;-.47) and sarcosine (SMD=-.5,95%CI=-.87-.13) outperformed placebo for total symptomatology. High heterogeneity (tau2=.10, I2=55.9%) and global inconsistency (Q=40.79, df=18, p=.002) emerged without publication bias (Egger's test, p=.42). Sarcosine improved negative symptoms (SMD=-.65, 95%CI=-1.10; -.19). N-acetylcysteine improved negative symptoms (SMD=-.90, 95%CI=-1.42; -.39)/general psychopathology (SMD=-.76, 95%CI=-1.39; -.13). No compound improved total symptomatology within acute phase studies (k=7, n=422). Sarcosine (SMD=-1.26,95%CI=-1.91; -.60), citicoline (SMD=-1.05,95%CI=-1.65;-.44), and N-acetylcysteine (SMD=-.55,95%CI=-.92,-.19) outperformed placebo augmentation in clinically stable participants. Sensitivity analyses removing high-risk-of-bias studies confirmed overall findings in all phases and clinically stable samples. In contrast, the acute phase analysis restricted to low risk-of-bias studies showed a superior effect vs. placebo for N-acetylcysteine (SMD=-1.10,95%CI=-1.75,-.45), L-lysine (SMD=-1.05,95%CI=-1.55,-.19), omega-3 fatty acids (SMD=-.83,95%CI=-1.31,-.34) and withania somnifera (SMD=-.71,95%CI=-1.21,-.22). Citicoline (SMD=-1.05,95%CI=-1.86,-.23), L-lysine (SMD=-1.04,95%CI=-1.84,-.24), N-acetylcysteine (SMD=-.89,95%CI=-1.35,-.43) and sarcosine (SMD=-.61,95%CI=-1.02,-.21) outperformed placebo augmentation of TAU ("any phase"). Drop-out due to any cause or adverse events did not differ between nutraceutical/phytoceutical vs. placebo+TAU.

Conclusions

Sarcosine, citicoline, and N-acetylcysteine are promising augmentation interventions in stable patients with schizophrenia, yet the quality of evidence is low to very low. Further high-quality trials in acute phases/specific outcomes/difficult-to-treat schizophrenia are warranted.

Pharmacological Treatment of Cognitive Impairment Associated With Schizophrenia: State of the Art and Future Perspectives

Cognitive Impairment Associated with Schizophrenia (CIAS) represents one of the core dimensions of Schizophrenia Spectrum Disorders (SSD), with an important negative impact on real-world functional outcomes of people living with SSD. Treatment of CIAS represents a therapeutic goal of considerable importance, and while cognition-oriented evidence-based psychosocial interventions are available, effective pharmacological treatment could represent a game-changer in the lives of people with SSD. The present critical review reports and discusses the evidence regarding the effects of several pharmacological agents that are available in clinical practice or are under study, commenting on both current and future perspectives of CIAS treatment. In particular, the effects on CIAS of antipsychotic medications, anticholinergic medications, benzodiazepines, which are currently commonly used in the treatment of SSD, and of iclepertin, d-serine, luvadaxistat, xanomeline-trospium, ulotaront, anti-inflammatory molecules, and oxytocin, which are undergoing regulatory trials or can be considered as experimental agents, will be reported and discussed. Currently, available pharmacological agents do not appear to provide substantial benefits on CIAS, but accurate management of antipsychotic medications and avoiding treatments that can further exacerbate CIAS represent important strategies. Some molecules that are currently being investigated in Phase 2 and Phase 3 trials have provided very promising preliminary results, but more information is currently required to assess their effectiveness in real-world contexts and to provide clear recommendations regarding their use in clinical practice. The results of ongoing and future studies will reveal whether any of these molecules represents the awaited pharmacological game-changer in the treatment of CIAS.

Placebo effects in mental health disorders: protocol for an umbrella review

INTRODUCTION

Given the high prevalence of mental health disorders and their significant socioeconomic burden, there is a need to develop improved treatments, and to evaluate them through placebo-controlled trials. However, the magnitude of the placebo response in randomised controlled trials to test medications may be substantial, affecting their interpretation. Therefore, improved understanding of the patient, trial and mental disorder factors that influence placebo responses would inform clinical trial design to better detect active treatment effects. There is a growing literature exploring the placebo response within specific mental health disorders, but no overarching synthesis of this research has been produced to date. We present a protocol for an umbrella review of systematic reviews and/or meta-analyses in which we aim to understand the effect size and potential predictors of placebo response within, and across, mental health disorders.

METHODS AND ANALYSIS

We will systematically search databases (Medline, PsycINFO, EMBASE+EMBASE Classic, Web of Knowledge) for systematic reviews and/or meta-analyses that report placebo effect size in clinical trials in patients with mental health disorders (initial search date 23 October 2022). Screening of abstracts and full texts will be done in pairs. We will extract data to qualitatively examine how placebo effect size varies across mental health disorders. We also plan to qualitatively summarise predictors of increased placebo response identified either quantitatively (eg, through meta-regression) or qualitatively. Risk of bias will be assessed using the AMSTAR-2 tool. We aim to not only summarise the current literature but also to identify gaps in knowledge and generate further hypotheses.

ETHICS AND DISSEMINATION

We do not believe there are any specific ethical considerations relevant to this study. We will publish the results in a peer-reviewed journal.

Protocol Development for a Qualitative Methodological Study Within a Trial (Qual-SWAT): The KARMA-Dep-2 Trial

Background

Despite methodological improvements in clinical trial design and conduct more generally, methodological limitations persist in trials concerning mental health care. A qualitative Study Within A Trial (Qual-SWAT), embedded in the KARMA-Dep-2 host trial, will be undertaken to explore and gain an understanding of two methodological questions in randomised trials specific to mental health care: (1) what are the key barriers and enablers of participation in randomised trials in mental health; and (2) how can randomised trials become part of routine mental health care. These issues will be examined from patient-participant and clinician- / researcher-participant perspectives, in alignment with PRioRiTy research themes.

Methods

A descriptive qualitative study design will be used. Data will be collected via one-to-one semi-structured interviews, conducted via Microsoft Teams. The interview data will be analysed using Braun and Clarke's Thematic Analysis approach. One-to-one interviews will be conducted with three participant groups ( N = 30): 1) host trial patient-participants ( n = 10); 2) potentially eligible host trial patient-participants who refused enrolment in the host trial ( n = 10); and 3) clinician- / researcher-participants who are associated with work on the host trial ( n = 10).

Ethics and dissemination

Ethical approval has been granted by St. Patrick's Mental Health Services Research Ethics Committee, Ireland (Ref: Protocol 09/20). When the study is completed, a report will be prepared and submitted to the Health Research Board (HRB). Findings will be shared with the host trial team and study participants, and submitted for publication.

Host trial registration

ClinicalTrials.gov ( NCT04939649); EudraCT ( 2019-003109-92). Official title: Ketamine as an Adjunctive Therapy for Major Depression - A Randomised Controlled Trial: [KARMA-Dep (2)].

Protocol Development for a Qualitative Methodological Study Within a Trial (Qual-SWAT): The KARMA-Dep-2 Trial

Background

Despite methodological improvements in clinical trial design and conduct more generally, methodological limitations persist in trials concerning mental health care. A qualitative Study Within A Trial (Qual-SWAT), embedded in the KARMA-Dep-2 host trial, will be undertaken to explore and gain an understanding of two methodological questions in randomised trials specific to mental health care: (1) what are the key barriers and enablers of participation in randomised trials in mental health; and (2) how can randomised trials become part of routine mental health care. These issues will be examined from patient-participant and clinician- / researcher-participant perspectives, in alignment with PRioRiTy research themes.

Methods

A descriptive qualitative study design will be used. Data will be collected via one-to-one semi-structured interviews, conducted via Microsoft Teams. The interview data will be analysed using Braun and Clarke's Thematic Analysis approach. One-to-one interviews will be conducted with three participant groups ( N = 30): 1) host trial patient-participants ( n = 10); 2) potentially eligible host trial patient-participants who refused enrolment in the host trial ( n = 10); and 3) clinician- / researcher-participants who are associated with work on the host trial ( n = 10).

Ethics and dissemination

Ethical approval has been granted by St. Patrick's Mental Health Services Research Ethics Committee, Ireland (Ref: Protocol 09/20). When the study is completed, a report will be prepared and submitted to the Health Research Board (HRB). Findings will be shared with the host trial team and study participants, and submitted for publication.

Host trial registration

ClinicalTrials.gov ( NCT04939649); EudraCT ( 2019-003109-92). Official title: Ketamine as an Adjunctive Therapy for Major Depression - A Randomised Controlled Trial: [KARMA-Dep (2)].

Expanded access to investigational drugs in psychiatry: A systematic review

Some psychiatric patients have exhausted all approved treatment options. Numerous investigational drugs are currently being developed and tested in clinical trials. However, not all patients can participate in clinical trials. Expanded access programs may provide an opportunity for patients who cannot participate in clinical trials to use investigational drugs as a therapeutic option outside of clinical trials. It is unknown to what extent expanded access occurs in psychiatry. We conducted a systematic literature search on PubMed, Embase, and PscyInfo, with additional information from ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform and FDA/EMA approvals, in order to find all expanded access programs ever conducted, globally, in the field of psychiatry. This resulted in a total of fourteen expanded access programs ever conducted in psychiatry. Given the prevalence of psychiatric disorders, the activity in clinical research in psychiatry, the regulatory framework enabling expanded access, and the impact of psychiatric disorders on patients, their families, and society, we had expected a higher utilization of expanded access. We propose that the psychiatric community, with pharmaceutical industry, should consider establishing and optimizing expanded access programs.

Rodent models for mood disorders - understanding molecular changes by investigating social behavior

Mood disorders, including depressive and bipolar disorders, are the group of psychiatric disorders with the highest prevalence and disease burden. However, their pathophysiology remains poorly understood. Animal models are an extremely useful tool for the investigation of molecular mechanisms underlying these disorders. For psychiatric symptom assessment in animals, a meaningful behavioral phenotype is needed. Social behaviors constitute naturally occurring complex behaviors in rodents and can therefore serve as such a phenotype, contributing to insights into disorder related molecular changes. In this narrative review, we give a fundamental overview of social behaviors in laboratory rodents, as well as their underlying neuronal mechanisms and their assessment. Relevant behavioral and molecular changes in models for mood disorders are presented and an outlook on promising future directions is given.

Switching to long-acting injectable antipsychotics: pharmacological considerations and practical approaches

INTRODUCTION

Long-acting injectable antipsychotics (LAIs) are an effective, but potentially underutilized treatment option in schizophrenia and other severe mental illnesses. Prescribing information typically focuses on how to initiate treatment from the corresponding oral formulations. However, in clinical practice other scenarios, such as switching from other oral antipsychotics or other LAIs, occur frequently, requiring guidance.

AREAS COVERED

Pharmacodynamic properties of antipsychotics and their relation to rebound symptoms. Pharmacokinetic properties of LAIs and their implications for switching approaches. Specific approaches to switching to LAIs.

EXPERT OPINION

The LAI landscape has evolved significantly in the last decade with more formulations available, longer dosing intervals, and extended indications. However, currently available LAIs have various shortcomings, e.g. short dosing intervals, need for oral supplementation, loading regimens, deep intramuscular injection and/or restricted indications. Recent improvements include a one-day initiation option for aripiprazole lauroxil, aripiprazole monohydrate once-monthly, risperidone in situ microparticles and subcutaneous risperidone. Future LAI developments should focus on longer dosing intervals, subcutaneous administration, expansion of LAIs beyond currently available antipsychotic agents and indications beyond schizophrenia and bipolar disorder. In the future, LAIs might become a first-line treatment after initial oral stabilization for chronic mental disorders with need for maintenance treatment and presence of significant non-adherence.

Major depressive disorder

Major depressive disorder (MDD) is characterized by persistent depressed mood, loss of interest or pleasure in previously enjoyable activities, recurrent thoughts of death, and physical and cognitive symptoms. People with MDD can have reduced quality of life owing to the disorder itself as well as related medical comorbidities, social factors, and impaired functional outcomes. MDD is a complex disorder that cannot be fully explained by any one single established biological or environmental pathway. Instead, MDD seems to be caused by a combination of genetic, environmental, psychological and biological factors. Treatment for MDD commonly involves pharmacological therapy with antidepressant medications, psychotherapy or a combination of both. In people with severe and/or treatment-resistant MDD, other biological therapies, such as electroconvulsive therapy, may also be offered.

Exploring Novel Therapeutic Approaches for Depressive Disorders: The Role of Allopregnanolone Agonists

Depressive disorders are caused due to the impaired functioning of important brain networks. Recent studies have also shown that it is caused by a significant reduction in the levels of allopregnanolone, which is a progesterone metabolite. Newer treatment modalities are now focusing on the usage of neuroactive steroids, such as allopregnanolone, in various depressive disorders. Our aim was to provide a comprehensive literature review on the clinical aspects of the allopregnanolone agonists brexanolone and zuranolone with reference to the physiological role of allopregnanolone. Brexanolone was approved by the FDA in 2019 for the treatment of postpartum depression and has greatly influenced further research into potential drugs such as zuranolone, which is currently undergoing phase 3 of clinical trials. Although these drugs exhibit improvement in symptoms of depressive disorders along with notable side effects, further research is required for their future clinical use.