Dopamine D2 receptor occupancy and cognition in schizophrenia: analysis of the CATIE data

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.

Blood metabolites, neurocognition and psychiatric disorders: a Mendelian randomization analysis to investigate causal pathways

BACKGROUND

Neurocognitive dysfunction is observationally associated with the risk of psychiatric disorders. Blood metabolites, which are readily accessible, may become highly promising biomarkers for brain disorders. However, the causal role of blood metabolites in neurocognitive function, and the biological pathways underlying their association with psychiatric disorders remain unclear.

METHODS

To explore their putative causalities, we conducted bidirectional two-sample Mendelian randomization (MR) using genetic variants associated with 317 human blood metabolites (nmax = 215,551), g-Factor (an integrated index of multiple neurocognitive tests with nmax = 332,050), and 10 different psychiatric disorders (n = 9,725 to 807,553) from the large-scale genome-wide association studies of European ancestry. Mediation analysis was used to assess the potential causal pathway among the candidate metabolite, neurocognitive trait and corresponding psychiatric disorder.

RESULTS

MR evidence indicated that genetically predicted acetylornithine was positively associated with g-Factor (0.035 standard deviation units increase in g-Factor per one standard deviation increase in acetylornithine level; 95% confidence interval, 0.021 to 0.049; P = 1.15 × 10-6). Genetically predicted butyrylcarnitine was negatively associated with g-Factor (0.028 standard deviation units decrease in g-Factor per one standard deviation increase in genetically proxied butyrylcarnitine; 95% confidence interval, -0.041 to -0.015; P = 1.31 × 10-5). There was no evidence of associations between genetically proxied g-Factor and metabolites. Furthermore, the mediation analysis via two-step MR revealed that the causal pathway from acetylornithine to bipolar disorder was partly mediated by g-Factor, with a mediated proportion of 37.1%. Besides, g-Factor mediated the causal pathway from butyrylcarnitine to schizophrenia, with a mediated proportion of 37.5%. Other neurocognitive traits from different sources provided consistent findings.

CONCLUSION

Our results provide genetic evidence that acetylornithine protects against bipolar disorder through neurocognitive abilities, while butyrylcarnitine has an adverse effect on schizophrenia through neurocognition. These findings may provide insight into interventions at the metabolic level for risk of neurocognitive and related disorders.

Using in silico methods to determine optimal tapering regimens for decanoate-based long-acting injectable psychosis drugs

Background

Reducing the dose of psychosis drugs in a gradual hyperbolic manner may minimise withdrawal effects and risk of relapse. There is presently limited guidance on tapering decanoate-based long-acting injectable dopamine antagonists (LIDAs).

Objectives

We aimed to apply hyperbolic principles of tapering to the decanoate-based LIDAs flupentixol, zuclopenthixol and haloperidol to develop withdrawal regimens.

Design

We used in silico methodology to predict plasma drug levels and D2 occupancy for different LIDA regimens.

Methods

Existing pharmacokinetic and receptor occupancy data from nuclear neuroimaging studies were used to power modelling. Abrupt discontinuation was examined as a potential strategy, and dose reduction was modelled with pre-defined constraints used in similar work of 10 (fast regimens), 5 (moderate) and 2.5 (slow) percentage points of D2 occupancy change per month.

Results

Abrupt discontinuation of decanoate-based LIDAs leads to excessive change in D2 occupancy which violated our pre-defined constraints, potentially resulting in withdrawal symptoms and increased risk of relapse. Reduction of LIDA dose allowed hyperbolic reduction in plasma level consistent with imposed constraints on receptor occupancy reduction rate. For equivalent per-weekly LIDA dosing, more frequent administration allowed a more gradual reduction of D2 occupancy. However, switching to oral forms is required to continue hyperbolic tapering to full discontinuation; reduction to zero using only LIDA produces too large a reduction in D2 occupancy. Guidance for reduction and cessation of LIDAs according to slow, moderate and fast criteria is provided.

Conclusion

Abrupt cessation of decanoate LIDAs is not consistent with gradual hyperbolic tapering, despite their longer half-lives compared with oral formulations. Reduction to the point of full discontinuation can only be achieved by switching to oral therapy to complete the taper. These results are limited by the in silico and theoretical nature of the study, and there is a need to confirm these findings through real-world observational and interventional studies.

Advancements in Non-Dopaminergic Treatments for Schizophrenia: A Systematic Review of Pipeline Developments

INTRODUCTION

Conventional antipsychotic drugs that attenuate dopaminergic neural transmission are ineffective in approximately one-third of patients with schizophrenia. This necessitates the development of non-dopaminergic agents.

METHODS

A systematic search was conducted for completed phase II and III trials of compounds for schizophrenia treatment using the US Clinical Trials Registry and the EU Clinical Trials Register. Compounds demonstrating significant superiority over placebo in the primary outcome measure in the latest phase II and III trials were identified. Collateral information on the included compounds was gathered through manual searches in PubMed and press releases.

RESULTS

Sixteen compounds were identified; four compounds (ulotaront, xanomeline/trospium chloride, vabicaserin, and roluperidone) were investigated as monotherapy and the remaining 12 (pimavanserin, bitopertin, BI 425809, encenicline, tropisetron, pregnenolone, D-serine, estradiol, tolcapone, valacyclovir, cannabidiol, and rimonabant) were examined as add-on therapy. Compared to the placebo, ulotaront, xanomeline/trospium chloride, vabicaserin, bitopertin, estradiol, cannabidiol, rimonabant, and D-serine showed efficacy for positive symptoms; roluperidone and pimavanserin were effective for negative symptoms; and encenicline, tropisetron, pregnenolone, tolcapone, BI 425809, and valacyclovir improved cognitive function.

DISCUSSION

Compounds that function differently from existing antipsychotics may offer novel symptom-specific therapeutic strategies for patients with schizophrenia.

Diverging functional connectivity timescales: Capturing distinct aspects of cognitive performance in early psychosis

BACKGROUND

Psychosis spectrum disorders (PSDs) are marked by cognitive impairments, the neurobiological correlates of which remain poorly understood. Here, we investigate the entropy of time-varying functional connectivity (TVFC) patterns from resting-state functional magnetic resonance imaging (rs-fMRI) as potential biomarker for cognitive performance in PSDs. By combining our results with multimodal reference data, we hope to generate new insights into the mechanisms underlying cognitive dysfunction in PSDs. We hypothesized that low-entropy TVFC patterns (LEN) would be more behaviorally informative than high-entropy TVFC patterns (HEN), especially for tasks that require extensive integration across diverse cognitive subdomains.

METHODS

rs-fMRI and behavioral data from 97 patients in the early phases of psychosis and 53 controls were analyzed. Positron emission tomography (PET) and magnetoencephalography (MEG) data were taken from a public repository (Hansen et al., 2022). Multivariate analyses were conducted to examine relationships between TVFC patterns at multiple spatial scales and cognitive performance in patients.

RESULTS

Compared to HEN, LEN explained significantly more cognitive variance on average in PSD patients, driven by superior encoding of information on psychometrically more integrated tasks. HEN better captured information in specific subdomains of executive functioning. Nodal HEN-LEN transitions were spatially aligned with neurobiological gradients reflecting monoaminergic transporter densities and MEG beta-power. Exploratory analyses revealed a close statistical relationship between LEN and positive symptom severity in patients.

CONCLUSION

Our entropy-based analysis of TVFC patterns dissociates distinct aspects of cognition in PSDs. By linking topographies of neurotransmission and oscillatory dynamics with cognitive performance, it enhances our understanding of the mechanisms underlying cognitive deficits in PSDs.

Diverging functional connectivity timescales: Capturing distinct aspects of cognitive performance in early psychosis

Background

Psychosis spectrum disorders (PSDs) are marked by cognitive impairments, the neurobiological correlates of which remain poorly understood. Here, we investigate the entropy of time-varying functional connectivity (TVFC) patterns from resting-state fMRI (rfMRI) as potential biomarker for cognitive performance in PSDs. By combining our results with multimodal reference data, we hope to generate new insights into the mechanisms underlying cognitive dysfunction in PSDs. We hypothesized that low-entropy TVFC patterns (LEN) would be more behaviorally informative than high-entropy TVFC patterns (HEN), especially for tasks that require extensive integration across diverse cognitive subdomains.

Methods

rfMRI and behavioral data from 97 patients in the early phases of psychosis and 53 controls were analyzed. Positron-Emission Tomography (PET) and magnetoencephalography (MEG) data were taken from a public repository (Hansen et al., 2022). Multivariate analyses were conducted to examine relationships between TVFC patterns at multiple spatial scales and cognitive performance in patients.

Results

Compared to HEN, LEN explained significantly more cognitive variance on average in PSD patients, driven by superior encoding of information on psychometrically more integrated tasks. HEN better captured information in specific subdomains of executive functioning. Nodal HEN-LEN transitions were spatially aligned with neurobiological gradients reflecting monoaminergic transporter densities and MEG beta power. Exploratory analyses revealed a close statistical relationship between LEN and positive PSD symptoms.

Conclusion

Our entropy-based analysis of TVFC patterns dissociates distinct aspects of cognition in PSDs. By linking topographies of neurotransmission and oscillatory dynamics with cognitive performance, it enhances our understanding of the mechanisms underlying cognitive deficits in PSDs.

CRediT Authorship Contribution Statement

Fabian Hirsch: Conceptualization, Methodology, Software, Formal analysis, Writing - Original Draft, Writing - Review & Editing, Visualization; Ângelo Bumanglag: Methodology, Software, Formal analysis, Writing - Review & Editing; Yifei Zhang: Methodology, Software, Formal analysis, Writing - Review & Editing; Afra Wohlschlaeger: Methodology, Writing - Review & Editing, Supervision, Project administration.

The Effect of Antipsychotics on Cognition in Schizophrenia-A Current Narrative Review

The majority of schizophrenia-affected individuals display deficiencies in multiple cognitive domains such as attention, working memory, long-term memory, and learning, deficiencies that are stable throughout the disease. The purpose of this narrative review was to examine the effect of antipsychotics on several cognitive domains affected by schizophrenia. Methods: We searched MEDLINE, Elsevier, Scopus, and DOAJ databases for randomized controlled trials and other studies investigating the effects of typical and atypical antipsychotics on cognition in patients with schizophrenia in studies conducted in the last decade. Results: The majority of studies included in this review showed that antipsychotics (especially SGAs) have positive effects on both cognition and general psychopathology of schizophrenia. We mention that treatment with antipsychotic substances represents an ongoing effort of the researchers, who are constantly searching for the best approach to meet the mental health needs of schizophrenia patients. Conclusions: Even with those positive results, it should be noted that more studies are needed in order to fully observe the various effects of certain antipsychotic substances on cognition.

A proposal for reducing maximum target doses of drugs for psychosis: Reviewing dose-response literature

BACKGROUND

Presently, there is limited guidance on the maximal dosing of psychosis drugs that is based on effectiveness rather than safety or toxicity. Current maximum dosing recommendations may far exceed the necessary degree of dopamine D2 receptor blockade required to treat psychosis. This may lead to excess harm through cognitive impairment and side effects.

AIMS

This analysis aimed to establish guidance for prescribers by optimally dosing drugs for psychosis based on efficacy and benefit.

METHODS

We used data from two dose-response meta-analyses and reviewed seven of the most prescribed drugs for psychosis in the UK. Where data were not available, we used appropriate comparison techniques based on D2 receptor occupancy to extrapolate our recommendations.

RESULTS

We found that the likely threshold dose for achieving remission of psychotic symptoms was often significantly below the currently licensed dose for these drugs. We therefore recommend that clinicians are cautious about exceeding our recommended doses. Individual factors, however, should be accounted for. We outline potentially relevant factors including age, ethnicity, sex, smoking status and pharmacogenetics. Additionally, we recommend therapeutic drug monitoring as a tool to determine individual pharmacokinetic variation.

CONCLUSIONS

In summary, we propose a new set of maximum target doses for psychosis drugs based on efficacy. Further research through randomised controlled trials should be undertaken to evaluate the effect of reducing doses from current licensing maximums or from doses that are above our recommendations. However, dose reductions should be implemented in a manner that accounts for and reduces the effects of drug withdrawal.

Unraveling the Influence of Age, IQ, Education, and Negative Symptoms on Neurocognitive Performance in Schizophrenia: A Conditional Inference Tree Analysis

INTRODUCTION

The complex nature of neurocognitive impairment in schizophrenia has been discussed in light of the mixed effects of antipsychotic drugs, psychotic symptoms, dopamine D2 receptor blockade, and intelligence quotient (IQ). These factors have not been thoroughly examined before.

METHODS

This study conducted a comprehensive re-analysis of the CATIE data using machine learning techniques, in particular Conditional Inference Tree (CTREE) analysis, to investigate associations between neurocognitive functions and moderating factors such as estimated trough dopamine D2 receptor blockade with risperidone, olanzapine, or ziprasidone, Positive and Negative Syndrome Scale (PANSS), and baseline IQ in 573 patients with schizophrenia.

RESULTS

The study reveals that IQ, age, and education consistently emerge as significant predictors across all neurocognitive domains. Furthermore, higher severity of PANSS-negative symptoms was associated with lower cognitive performance scores in several domains. CTREE analysis, in combination with a genetic algorithm approach, has been identified as particularly insightful for illustrating complex interactions between variables. Lower neurocognitive function was associated with factors such as age>52 years, IQ<94/95,<12/13 education years, and more pronounced negative symptoms (score<26).

CONCLUSIONS

These findings emphasize the multifaceted nature of neurocognitive functioning in patients with schizophrenia, with the PANSS-negative score being an important predictor. This gives rise to a role in addressing negative symptoms as a therapeutic objective for enhancing cognitive impairments in these patients. Further research must examine nonlinear relationships among various moderating factors identified in this work, especially the role of D2 occupancy.

Effect of anticholinergic burden on brain activity during Working Memory and real-world functioning in patients with schizophrenia

Cognitive impairment has been associated with poor real-world functioning in patients with Schizophrenia. Previous studies have shown that pharmacological treatment with anticholinergic properties may contribute to cognitive impairment in Schizophrenia. We investigated the effect of the anticholinergic burden (ACB) on brain activity, cognition, and real-world functioning in Schizophrenia. We hypothesized that greater ACB would be associated with altered brain activity along with poorer cognitive performance and lower real-world functioning. A sample of 100 patients with a diagnosis of schizophrenia or schizoaffective disorder was recruited in the naturalistic multicenter study of the Italian Network for Research on Psychoses (NIRP) across 7 centres. For each participant, ACB was evaluated using the Anticholinergic Cognitive Burden scale. The association of ACB with brain function was assessed using BOLD fMRI during the N-Back Working Memory (WM) task in a nested cohort (N = 31). Real-world functioning was assessed using the Specific Level of Functioning (SLOF) scale. Patients with high ACB scores (≥3) showed lower brain activity in the WM frontoparietal network (TFCE corrected alpha <0.05) and poorer cognitive performance (p = 0.05) than patients with low ACB scores (<3). Both effects were unaffected by demographic characteristics, clinical severity, and antipsychotic dosage. Moreover, patients with high ACB showed poorer real-world functioning than patients with lower ACB (p = 0.03). Our results suggest that ACB in Schizophrenia is associated with impaired WM and abnormal underlying brain function along with reduced real-world functioning. Clinical practice should consider the potential adverse cognitive effects of ACB in the treatment decision-making process.

Development and acceptability testing of a decision aid for considering whether to reduce antipsychotics in individuals with stable schizophrenia

AIM

Continued antipsychotic treatment is the key to preventing relapse. Maintenance antipsychotic monotherapy and optimal dose use are recommended for individuals with stable schizophrenia because of their undesirable effects. Decision aids (DAs) are clinical conversation tools that facilitate shared decision-making (SDM) between patients and health-care providers. This study aimed to describe the development process and results of acceptability testing of a DA for individuals with stable schizophrenia, considering (i) whether to continue high-dose antipsychotics or reduce to the standard dose and (ii) whether to continue two antipsychotics or shift to monotherapy.

METHODS

A DA was developed according to the guidelines for the appropriate use of psychotropic medications and International Patient Decision Aid Standards (IPDAS). First, a DA prototype was developed based on a previous systematic review and meta-analysis conducted for identifying the effects of continuing or reducing antipsychotic treatment. Second, mixed-method survey was performed among individuals with schizophrenia and health-care providers to modify and finalize the DA.

RESULTS

The DA consisted of an explanation of schizophrenia, options to continue high-dose antipsychotics or reduce to the standard dose, options to continue two antipsychotics or shift to monotherapy, pros and cons of each option, and a value-clarification worksheet for each option. The patients (n = 20) reported acceptable language use (75%), adequate information (75%), and well-balanced presentation (79%). Health-care providers (n = 20) also provided favorable overall feedback. The final DA covered six IPDAS qualifying criteria.

CONCLUSION

A DA was successfully developed for schizophrenia, considering whether to reduce antipsychotics, which can be used in the SDM process.

Structure-Activity Relationship Studies on 6-Chloro-1-phenylbenzazepines Leads to the Identification of a New Dopamine D1 Receptor Antagonist

The 1-phenylbenzazepine template has yielded a number of D1R-like ligands, which, though useful as pharmacological tools, have significant drawbacks in terms of selectivity versus D5R as well as pharmacokinetic behavior. A number of 1-phenylbenzazepines contain a 6-chloro functional group, but extensive SAR studies around the 6-chloro-1-phenylbenzazepine framework have not been reported in the literature. To further understand the tolerance of the 6-chloro-1-phenylbenzazepine template for various substituent groups towards affinity and selectivity at D1R, we synthesized two series of analogs with structural variations at the C-7, C-8, N-3, C-3' and C-4' positions. The series 2 analogs differed from series 1 analogs in possessing a nitrogenated functionality at C-8 and lacked a C-4' substituent, but were otherwise similar. Analogs were assessed for affinity at D1R, D2R and D5R. For both series, we found that the analogs lacked affinity for D2R and showed modest D1R versus D5R selectivity. For series 1 analogs, an N-3 methyl substituent group was better tolerated than N-H or an N-3 allyl substituent. The C-8 position appears to be tolerant of amino and methanesulfonamide substituents for high D1R affinity, but C-8 amides displayed low to moderate D1R affinities. A C-3' methyl substituent appeared to be critical for the D1R affinity of some analogs, but the C-4' substituents tried (hydroxy and methoxy; series 1) did not result in any significant boost in D1R affinity. Compound 15a was the most potent and selective D1R ligand identified from these studies (Ki at D1R = 30 nM; 6-fold selectivity versus D5R). Further functional activity assessments indicate that 15a functions as a D1R antagonist towards cAMP-mediated signaling. The predicted drug-like properties of 15a are encouraging for further pharmacological assessments on the compound.

Link between cognitive polygenic risk scores and clinical progression after a first-psychotic episode

BACKGROUND

Clinical intervention in early stages of psychotic disorders is crucial for the prevention of severe symptomatology trajectories and poor outcomes. Genetic variability is studied as a promising modulator of prognosis, thus novel approaches considering the polygenic nature of these complex phenotypes are required to unravel the mechanisms underlying the early progression of the disorder.

METHODS

The sample comprised of 233 first-episode psychosis (FEP) subjects with clinical and cognitive data assessed periodically for a 2-year period and 150 matched controls. Polygenic risk scores (PRSs) for schizophrenia, bipolar disorder, depression, education attainment and cognitive performance were used to assess the genetic risk of FEP and to characterize their association with premorbid, baseline and progression of clinical and cognitive status.

RESULTS

Schizophrenia, bipolar disorder and cognitive performance PRSs were associated with an increased risk of FEP [false discovery rate (FDR) ⩽ 0.027]. In FEP patients, increased cognitive PRSs were found for FEP patients with more cognitive reserve (FDR ⩽ 0.037). PRSs reflecting a genetic liability for improved cognition were associated with a better course of symptoms, functionality and working memory (FDR ⩽ 0.039). Moreover, the PRS of depression was associated with a worse trajectory of the executive function and the general cognitive status (FDR ⩽ 0.001).

CONCLUSIONS

Our study provides novel evidence of the polygenic bases of psychosis and its clinical manifestation in its first stage. The consistent effect of cognitive PRSs on the early clinical progression suggests that the mechanisms underlying the psychotic episode and its severity could be partially independent.

Cognitive impairment in adults under compulsory psychiatric care: association with psychotic symptoms and high-dose antipsychotics

BACKGROUND

There is limited evidence on the association between cognitive function, psychotic symptoms and doses of antipsychotics in adults under compulsory psychiatric care.

AIMS

We assessed (a) the degree of cognitive impairment in adults involuntarily hospitalised for compulsory psychiatric care and (b) correlation of Montreal Cognitive Assessment (MoCA) score with psychotic symptoms, polypharmacy and prescription of high-dose antipsychotics.

METHOD

This was a nationwide, cross-sectional study, conducted at the only referral state hospital for compulsory psychiatric care in Cyprus (December 2016-February 2018). Τhe MoCA was applied for the assessment of cognitive functioning. The Positive and Negative Syndrome Scale (PANSS) was applied for the assessment of psychotic symptoms.

RESULTS

The sample comprised 187 men and 116 women. The mean MoCA score was 22.09 (reported scale range (RSR): 3-30); the mean PANSS general symptoms subscale score was 49.60 (RSR = 41-162). The participants who reported positive psychiatric history (mean 21.71, s.d. 5.37), non-adherence to pharmacotherapy (mean 21.32, s.d. 5.56) and prescription of high-dose antipsychotics (with medication prescribed as needed: mean 21.31, s.d. 5.70; without medication prescribed as needed: mean 20.71, s.d. 5.78) had lower mean MoCA scores compared with those who reported negative psychiatric history (mean 23.42, s.d. 4.51; P = 0.017), adherence to pharmacotherapy (mean 23.10, s.d. 6.61; P = 0.003) and no prescription of high-dose antipsychotics (with medication prescribed as needed: mean 22.56, s.d. 4.90; without medication prescribed as needed: mean 22.60 s.d. 4.94; P = 0.045-0.005), respectively. Mean MoCA score was mildly and inversely associated with total PANSS score (r = -0.15, P = 0.03), PANSS general (r = -0.18, P = 0.002) and PANSS negative (r = -0.16, P = 0.005) symptoms subscales, respectively.

CONCLUSIONS

Our findings support the evaluation of cognitive functioning in adults under compulsory psychiatric care via the MoCA tool, with focus on those prescribed high-dose antipsychotics, with positive mental health history and non-adherence to pharmacotherapy.

Neurocognitive correlates of the varied domains of outcomes at 20 year follow-up of first-episode psychosis

Little is known about long-term outcomes of the first episode of psychosis (FEP) other than in the symptomatic domain. We hypothesised that cognitive impairment is associated with poorer multi-domain outcomes at a long-term follow-up of FEP patients. We followed-up 172 FEP patients for a mean of 20.3 years. Ten outcome dimensions were assessed (symptomatic, functional and personal recovery, social disadvantage, physical health, suicide attempts, number of episodes, current drug use, chlorpromazine equivalent doses (CPZ), and schizophrenia/schizoaffective disorder final diagnosis). Cognition was assessed at follow-up. Processing speed and verbal memory deficits showed significant associations with poor outcomes on symptomatic, social functioning, social disadvantage, higher number of episodes, and higher CPZ. Significant associations were found between visual memory impairments were significantly associated with low symptomatic and functional recovery, between attentional deficits and a final diagnosis of schizophrenia/schizoaffective disorder, and between social cognition deficits and poor personal recovery.Lower cognitive global scores were significantly associated with all outcome dimensions except for drug abuse and physical status. Using multiple outcome dimensions allowed for the inclusion of the patients' perspective and other commonly neglected outcome measures. Taken together, cognitive impairment in FEP patients is strongly related to poor performance on several outcome dimensions beyond symptomatic remission.

Relapse of first-episode schizophrenia patients and neurocognitive impairment: The role of dopaminergic and anticholinergic burden

BACKGROUND

The prevention of relapse may be a key factor to diminish the cognitive impairment of first-episode schizophrenia (FES) patients. We aimed to ascertain the effects of relapse, and dopaminergic and anticholinergic treatment burdens on cognitive functioning in the follow-up.

METHODS

Ninety-nine FES patients participated in this study. Cognitive assessments were performed at baseline and after 3 years of follow-up or, in those patients who relapsed, after &gt;2 months of stabilization of the new acute psychotic episode. The primary outcomes were final cognitive dimensions.

RESULTS

Repeated measures MANOVA analyses showed improvements in the whole sample on the end-point assessments in processing speed and social cognition. However, only impairment in social cognition showed a significant interaction with relapse by time in this sample. Relapse in FES patients was significantly associated with poor performance on end-point assessments of working memory, social cognition and global cognitive score. Anticholinergic burden, but not dopaminergic burden, was associated with verbal memory impairment. These significant associations resulted after controlling for baseline cognitive functioning, relapse and dopaminergic burden.

CONCLUSIONS

The relationship between relapse and cognitive impairment in recovered FES patients seems to be particularly complex at the short-term follow-up of these patients. While relapse was associated with working memory, social cognition impairments and global cognitive score, anticholinergic burden might play an additional worsening effect on verbal memory. Thus, tailoring or changing antipsychotics and other drugs to reduce their anticholinergic burden may be a potential modifiable factor to diminish cognitive impairment at this stage of the illness.

Cognitive dysfunction in schizophrenia: An expert group paper on the current state of the art

Cognitive impairment in schizophrenia represents one of the main obstacles to clinical and functional recovery. This expert group paper brings together experts in schizophrenia treatment to discuss scientific progress in the domain of cognitive impairment to address cognitive impairments and their consequences in the most effective way. We report on the onset and course of cognitive deficits, linking them to the alterations in brain function and structure in schizophrenia and discussing their role in predicting the transition to psychosis in people at risk. We then address the assessment tools with reference to functioning and social cognition, examining the role of subjective measures and addressing new methods for measuring functional outcomes including technology based approaches. Finally, we briefly review treatment options for cognitive deficits, focusing on cognitive remediation programs, highlighting their effects on brain activity and conclude with the potential benefit of individualized integrated interventions combing cognitive remediation with other approaches.

Effect of antipsychotic dose reduction on cognitive function in schizophrenia

Cognitive deficits are predictors of social functioning but remain an unmet therapeutic challenge. While lowering the antipsychotics carries a risk of relapse, it possibly has a beneficial effect on cognitive function. However, this has not been examined in a real-world setting. A prospective naturalistic 6-month follow-up study (n = 71) was conducted with patients between 18 and 45 years in their first five years of illness and the maintenance phase of the treatment. Brief Assessment of Cognition in Schizophrenia (BACS) was administered to assess cognitive functions. Patients were divided into three groups based on the change in dose of antipsychotics. The data were analyzed using linear mixed-effects modeling (LMEM) to examine the group differences. At the end of six months, those with decreased antipsychotic dose had significant improvement in BACS total score, token test, and symbol coding compared to those with no change in the dose of antipsychotic. Reducing the dose of antipsychotics during the maintenance phase was associated with improved cognitive functions without an increased risk of relapse. Antipsychotic dose reduction may be better than discontinuation as the relapse risk is higher with the discontinuation strategy. Clinicians must balance the improvements in cognitive functions and relapse risk.

Protocol of guided antipsychotic reduction to reach minimum effective dose (GARMED) in patients with remitted psychosis based on pragmatic design

AIMS

Patients with psychosis intend to discontinue antipsychotic treatment for various reasons. As antipsychotic discontinuation involves a high risk of relapse, maintenance treatment is recommended by mainstream opinion even when remission is attained. To optimize the risk-to-benefit ratio of long-term antipsychotic treatment, we proposed an operationalized guided dose-reduction algorithm to serve as an intermediate approach as to achieve the lowest effective antipsychotic dose and better functioning for patients with remitted psychosis.

METHODS

Outpatients with a history of schizophrenia-related psychotic disorders currently under stable medications and symptoms are eligible to register in this protocol. Patients intending for dose reduction are randomized into 2:1, guided dose reduction group (GDR) versus maintenance treatment group (MTG1). Eligible patients who do not intend to reduce antipsychotics serve as naturalistic maintenance controls (MTG2). The GDR patients reduce no more than 25% of their baseline antipsychotic dose, with at least a 6-month stabilization period before reducing another 25% of their last dose. The timing of the next dose reduction will be determined by shared decision-making with the patient. Following a dose reduction, the patients will receive three consecutive monthly monitoring; otherwise, they receive treatment as usual.

DISCUSSION

By employing this pragmatic-based protocol, patients are empowered to evaluate their readiness for next dose reduction attempt. We would like to test in real-world situations if stable patients can reduce antipsychotics not at the expense of an increased risk of relapse, so as to optimize the balance between risk-to-benefit ratios of long-term antipsychotic treatment.

Exploring Hidden Issues in the Use of Antipsychotic Polypharmacy in the Treatment of Schizophrenia

The mainstay of schizophrenia treatment is pharmacological therapy using various antipsychotics including first- and second-generation antipsychotics which have different pharmacokinetic and pharmacodynamic property leading to differential presentation of adverse events (AEs) and treatment effects such as negative symptoms, cognitive symptoms and cormorbid symptoms. Major treatment guidelines suggest the use of antipsychotic monotherapy (APM) as a gold standard in the treatment of schizophrenia. However, the effects of APM is inadequate and less potent to achieve symptom remission as well as functional recovery in real practice which has been consistently reported in numerous controlled clinical trials, large practical trials, independent small studies and systematic reviews till today. Therefore anti-psychotic polypharmacy (APP) regardless of the class of antipsychotics has been also commonly utilized for many reasons in real world practice. However, APP has also crucial pitfalls including increase of total psychotics including antipsychotics, high-doses of antipsychotics used, poor compliance, drug-drug interaction and risks for developing AEs, all of which are paradoxically related to poor clinical outcomes, whereas APP has also substantial advantages in reduction of re-hospitalization, severe psychopathology and targeted control of concurrent symptoms. Given currently limited therapeutic options, it is also important to properly utilize APP in order to maximize its clinical utility and minimize its risk for better treatment outcomes for patients with schizophrenia, based on risk/benefit with full understanding of pharmacological and clinical issues on APP. The present paper intends to address intriguing and important issues in the use of APP in real world practice.

Clinical Characteristics of Patients with Schizophrenia Maintained without Antipsychotics: A Cross-sectional Survey of a Case Series

Objective

While antipsychotics are necessary for relapse prevention in the treatment of schizophrenia in general, some minority of patients may be maintained without continuous antipsychotic treatment. However, the characteristics of such patients are not well known and previous reports have not evaluated key elements such as physical comorbidities and functioning.

Methods

Among 635 patients with schizophrenia who participated in a 12-year follow-up, those who were maintained without antipsychotic treatment for at least one year after the study were investigated. The patients underwent comprehensive assessments, including Positive and Negative Syndrome Scale (PANSS) for psychopathology, Cumulative Illness Rating Scale for Geriatrics (CIRS-G) for physical comorbidities, and Functional Assessment for Comprehensive Treatment of Schizophrenia (FACT-Sz), Barthel Index, and EuroQoL five dimensions (EQ5D) for function.

Results

Six patients were included (mean ± standard deviation age, 66.8 ± 17.4 years; 4 inpatients). The four inpatients were old (77.8 ± 4.8 years) and chronically ill (duration of illness, 49.3 ± 12.5 years) with a high PANSS score (total score, 118.0 ± 9.8; negative syndrome subscale, 41.3 ± 6.9), low functioning (FACT-Sz, 9.8 ± 3.6; Barthel Index, 8.8 ± 9.6), and serious physical comorbidities (CIRS-G, 15.5 ± 1.1). By contrast, the two outpatients were relatively young (45.0 ± 12.0 years) and clinically in good condition (PANSS total score, 44.5 ± 0.5; Barthel Index, 100 for both; EQ5D, 0.85 ± 0.04).

Conclusion

Although the number is limited, two types of patients with schizophrenia were identified who were free from ongoing antipsychotic treatment; 1) older chronic inpatients with serious physical comorbidities, and 2) younger outpatients with milder impairments. Future explorations are needed to identify those who will be successfully withdrawn from continuous antipsychotic treatment.

Durable Cognitive Gains and Symptom Improvement Are Observed in Individuals With Recent-Onset Schizophrenia 6 Months After a Randomized Trial of Auditory Training Completed Remotely

OBJECTIVE

Cognitive impairment in schizophrenia predicts functional outcomes and is largely unresponsive to pharmacology or psychotherapy; it is thus a critical unmet treatment need. This article presents the impact of remotely completed, intensive, targeted auditory training (AT) vs control condition computer games (CG) in a double-blind randomized trial in young adults with recent-onset schizophrenia.

METHOD

Participants (N = 147) were assessed for cognition, symptoms, and functioning at baseline, post-intervention, and at 6-month follow-up. All participants were provided with laptop computers and were instructed to complete 40 hours remotely of training or computer games. An intent-to-treat analysis (N = 145) was performed using linear mixed models with time modeled as a continuous variable. Planned contrasts tested the change from baseline to post-training, baseline to 6-month follow-up, and post-training to 6-month follow-up.

RESULTS

Global Cognition, which had improved in the AT group relative to the CG group at post-training, showed durable gains at 6-month follow-up in an omnibus group-by-time interaction test (F(1,179) = 4.80, P = .030), as did Problem-Solving (F(1,179) = 5.13, P = .025), and Speed of Processing improved at trend level significance (F(1,170) = 3.80, P = .053). Furthermore, the AT group showed significantly greater improvement than the CG group in positive symptoms (F(1,179) = 4.06, P = .045).

CONCLUSIONS

These results provide the first evidence of durable cognitive gains and symptom improvement at follow-up of cognitive training (CT) in early schizophrenia completed independently and remotely. While functioning did not show significant improvement, these findings suggest that intensive targeted CT of auditory processing is a promising component of early intervention to promote recovery from psychosis.

Incidence of Orthostatic Hypotension in Schizophrenic Patients Using Antipsychotics at Sambang Lihum Mental Health Hospital, South Kalimantan

Schizophrenia is a psychiatric disorder that requires antipsychotics therapy. Antipsychotics cause many side effects, including orthostatic hypotension. The study aimed to describe the incidence of orthostatic hypotensive side effects experiences by schizophrenia patients at the Sambang Lihum Mental Health Hospital, South Kalimantan. This research was observational description research with data sampling by medical records. This research was conducted to 300 medical records of patients period January-December 2018 which received antipsychotics medication and data analyzed by univariate analysis. The results showed the number of patients who experienced orthostatic hypotension was 98 patients (32.67%) and no experienced were 202 patients (67.33%). Incidence of orthostatic hypotension in haloperidol 54.35% (N=46); trifluoperazine 100% (N=1); clozapine 84.62% (N=13); olanzapine 100% (N=1); haloperidol-chlorpromazine 27.27% (N=11); haloperidol-haloperidol 42.86% (N=7); clozapine-risperidone 16.67% (N=6); haloperidol-clozapine 15.05% (N=93); haloperidol-olanzapine 50% (N=2); haloperidol-risperidone 31.82% (N=22); trifluoperazine-olanzapine 100% (N=1); trifluoperazine-clozapine 22.22% (N=9); trifluoperazine-risperidone 5.56% (N=18); chlorpromazine-haloperidol-haloperidol 33.3% (N=3); chlorpromazine-haloperidol-trifluoperazine 100% (N=3); haloperidol-trifluoperazine-chlorpromazine 100% (N=1); chlorpromazine-haloperidol-clozapine 42.86% (N=7); chlorpromazine-trifluoperazine-clozapine 100% (N=1); chlorpromazine-trifluoperazine-olanzapine 100% (N=1); chlorpromazine-trifluoperazine-risperidone 50% (N=2); trifluoperazine-haloperidol-risperidone 100% (N=4); haloperidol-trifluoperazine-risperidone 100% (N=1); trifluoperazine-haloperidol-clozapine 40% (N=5); haloperidol-haloperidol-clozapine 80% (N=5); clozapine-risperidone-trifluoperazine 100% (N=4); risperidone-clozapine-haloperidol 20% (N=10). The conclusion from this study was the percentage of orthostatic hypotension on schizophrenia patients at the Sambang Lihum Mental Health Hospital was 32.67% (N=98).

Antipsychotic Polypharmacy Among Patients With Schizophrenia in Africa: A Systematic Review and Meta-Analysis

OBJECTIVES

In Africa, antipsychotic polypharmacy (APP) is increasing due to a high antipsychotic dose prescribing, repeated psychiatric hospitalization, uncontrolled psychotic symptoms, and greater side effect burden. Therefore, the aim of this review and meta-analysis is to assess the prevalence and correlates of APP among patients with schizophrenia in Africa.

METHODS

A systematic search was performed from August 1 to 31, 2020, on PubMed, MEDLINE, Google Scholar, and Science Direct databases to select articles based on the inclusion criteria. Meta-Analysis of Observational studies in Epidemiology guidelines were employed. Cross-sectional observational studies that reported APP and/or its correlates in schizophrenia patients in English language published in peer-reviewed journals without time limits were included in the review. The quality of included articles was assessed using Newcastle-Ottawa quality assessment tool. Prevalence and correlates of APP were the outcome measures of this review and meta-analysis. Open Meta Analyst and RevMan version 5.3 software were used for meta-analysis. A random effect model was used to synthesize data based on the heterogeneity test.

RESULTS

Six studies that involved 2154 schizophrenia patients met the inclusion criteria in this review and meta-analysis. The quality of included studies ranges from 6.5 to 10 based on the Newcastle-Ottawa quality assessment tool. The pooled prevalence of APP among patients with schizophrenia was 40.6% with 95% confidence interval: 27.6% to 53.7%. Depot first-generation antipsychotics and oral first-generation antipsychotics were the most commonly prescribed APP combinations. Socio-demographic, clinical, and antipsychotic treatment characteristics were significantly associated with APP. There was a wide variation in the correlates of APP assessed by studies and the way that association/correlations was determined and reported.

CONCLUSIONS

APP is common and highly prevalent. Advanced age, male gender, longer duration of schizophrenia, hospital admission, and longer antipsychotic treatment were correlates of APP in Africa.

Minireview: Animal model of schizophrenia from the perspective of behavioral pharmacology: Effect of treatment on cognitive functions

Schizophrenia is a debilitating mental disorder characterized by positive, negative and cognitive symptoms. Whereas positive symptoms are satisfactorily addressed by current antipsychotic treatment, negative and cognitive symptomatic treatment remains largely ineffective. This review investigates the treatment efficacy regarding cognitive symptoms and evaluates the contribution of different monoamine receptor systems involved in schizophrenia pathophysiology to cognition. In the review, we included preclinical studies assessing the effect of different treatments on cognition in pre-pulse inhibition and two spatial cognitive tests. While pre-pulse inhibition investigates pre-attentive processes operating outside of conscious awareness, the spatial tasks require continuous attention and active engagement in task solving for a successful outcome. The schizophrenia-like phenotype was attained by acute or subchronic administration of non-competitive NMDA receptor antagonist MK-801.

Cannabidiol and Amisulpride Improve Cognition in Acute Schizophrenia in an Explorative, Double-Blind, Active-Controlled, Randomized Clinical Trial

Cannabidiol (CBD), a principal phytocannabinoid constituent, has demonstrated antipsychotic properties in recent clinical trials. While it has also been suggested a promising candidate for the treatment of neurodegenerative disorders, it failed to demonstrate efficacy in cognitive impairments associated with schizophrenia as an add-on treatment (600 mg/day for 6 weeks) in 18 chronically ill patients co-treated with a variety of psychopharmacologic drugs. Here, we report on the results of parallel-group, active-controlled, mono-therapeutic, double-blind, randomized clinical trial (CBD-CT1; ClinicalTrials.gov identifier: NCT00628290) in 42 acute paranoid schizophrenic patients receiving either CBD (up to 800 mg/day) or amisulpride (AMI, up to 800 mg/day) for four weeks in an inpatient setting with neurocognition as a secondary objective. Twentynine patients (15 and 14 in the CBD and AMI group, respectively) completed two cognitive assessments at baseline and the end of the treatment period. We investigated the following cognitive domains: pattern recognition, attention, working memory, verbal and visual memory and learning, processing speed, and verbal executive functions. When applying the Bonferroni correction for multiple testing, p < 0.0004 would indicate statistical significance. There was no relevant difference in neurocognitive performance between the CBD and the AMI group at baseline, and we observed no post-treatment differences between both groups. However, we observed improvements within both groups from pre-to post-treatment (standardized differences reported as Cohen’s d) in visual memory (CBD: 0.49, p = 0.015 vs. AMI: 0.63, p = 0.018) and processing speed (CBD: 0.41, p = 0.004 vs. AMI: 0.57, p = 0.023). Furthermore, CBD improved sustained attention (CBD: 0.47, p = 0.013, vs. AMI: 0.52, p = 0.085), and visuomotor coordination (CBD: 0.32, p = 0.010 vs. AMI: 0.63, p = 0.088) while AMI led to enhanced working memory performance in two different paradigms (Subject Ordered Pointing Task–AMI: 0.53, p = 0.043 vs. CBD: 0.03, p = 0.932 and Letter Number Sequencing–AMI: 0.67, p = 0.017 vs. CBD: 0.08 p = 0.755). There was no relevant correlation between changes in neurocognitive parameters and psychotic symptoms or anandamide serum levels. This study shows that both CBD and AMI improve neurocognitive functioning with comparable efficacy in young and acutely ill schizophrenia patients via an anandamide-independent mechanism.

Antipsychotic Polypharmacy and High-Dose Antipsychotics in Involuntary Patients: a Seven-Year Audit of Discharge Prescriptions in an Acute Care Unit

Antipsychotic polypharmacy (APP) is a psychopharmacological practice in which two or more antipsychotics are prescribed simultaneously. Despite the absence of evidence to support it, it is highly prevalent in clinical settings. Another recurrent practice strongly associated with APP is the prescription of high-dose antipsychotics (HDAs). Compulsory treatment is a legal means to impose treatment on an individual suffering from mental illness who refuses therapeutic intervention. Compulsory treatment has been associated with APP and HDAs and rates of both have been proposed to represent indicators of the quality of prescribing. We aimed to perform an antipsychotic prescription audit in a vulnerable psychiatric population, at the psychiatry department of a district hospital in Portugal, across 7 years. We evaluated APP and HDAs in 403 compulsorily admitted patients by reviewing their files at discharge. We used logistic regression to search for factors associated with APP and HDAs. APP was found in 70.5% of individuals, whereas HDAs were found in 51.4%. After adjustment, APP was significantly associated with male gender (Odds Ratio[OR] = 1.85 [1.04; 3.30] 95% Confidence Interval [CI]), involuntary outpatient treatment (OR = .40 [.18; .82] 95% CI), activation of the hospital social services (OR = 1.91 [1.08; 3.38] 95%CI), prescription of antidepressants (OR = .43 [.22; .82] 95%CI) and long-acting injectables (LAI) (OR = 28.29 [13.13; 60.97] 95%CI). HDAs were associated with male gender (OR = 1.76 [1.06; 2.94] 95%CI), the prescription of LAI (OR = 12.92 [6.93; 24.09] 95%CI) and oral first-generation antipsychotics (OR = 2.90 [1.51; 5.60] 95%CI).

Longitudinal changes in antipsychotic dose in patients treated with long-acting injectable second-generation antipsychotics

Only a few studies have investigated changes in the dose of long-acting injectable second-generation antipsychotics (LAI-SGAs) over the long term in the maintenance treatment of schizophrenia. In this retrospective cohort study, we examined longitudinal changes in antipsychotic dose over a 3-year period in patients with schizophrenia who had been taking LAI-SGAs for at least 1 year. We compared the total daily chlorpromazine equivalent dose of antipsychotics at 12, 24 and 36 months with the baseline dose at 3 months after initiation of LAI-SGAs. We also performed multiple regression analysis to explore factors associated with change in total daily dose 12 months after treatment initiation. A total of 154 patients fulfilled the inclusion criteria. There was no significant difference in total daily antipsychotic dose between 3 months and 12, 24 or 36 months after treatment initiation. Total daily dose was increased in 43 (27.9%), 31 (34.8%) and 22 patients (36.7%) at 12, 24 and 36 months, respectively. Age and total antipsychotic dose at 3 months were significantly negatively associated with change in total daily dose. Antipsychotic dose was basically unchanged during long-term treatment in patients treated with LAI-SGAs in the maintenance phase, although there was an increase in some patients.

The Pan social brain: An evolutionary history of neurochemical receptor genes and their potential impact on sociocognitive differences

Humans have unique cognitive capacities that, compared with apes, are not only simply expressed as a higher level of general intelligence, but also as a quantitative difference in sociocognitive skills. Humans' closest living relatives, bonobos (Pan paniscus), and chimpanzees (Pan troglodytes), show key between-species differences in social cognition despite their close phylogenetic relatedness, with bonobos arguably showing greater similarities to humans. To better understand the evolution of these traits, we investigate the neurochemical mechanisms underlying sociocognitive skills by focusing on variation in genes encoding proteins with well-documented roles in mammalian social cognition: the receptors for vasopressin (AVPR1A), oxytocin (OXTR), serotonin (HTR1A), and dopamine (DRD2). Although these genes have been well studied in humans, little is known about variation in these genes that may underlie differences in social behavior and cognition in apes. We comparatively analyzed sequence data for 33 bonobos and 57 chimpanzees, together with orthologous sequence data for other apes. In all four genes, we describe genetic variants that alter the amino acid sequence of the respective receptors, raising the possibility that ligand binding or signal transduction may be impacted. Overall, bonobos show 57% more fixed substitutions than chimpanzees compared with the ancestral Pan lineage. Chimpanzees, show 31% more polymorphic coding variation, in line with their larger historical effective population size estimates and current wider distribution. An extensive literature review comparing allelic changes in Pan with known human behavioral variants revealed evidence of homologous evolution in bonobos and humans (OXTR rs4686301(T) and rs237897(A)), while humans and chimpanzees shared OXTR rs2228485(A), DRD2 rs6277(A), and DRD2 rs11214613(A) to the exclusion of bonobos. Our results offer the first in-depth comparison of neurochemical receptor gene variation in Pan and put forward new variants for future behavior-genotype association studies in apes, which can increase our understanding of the evolution of social cognition in modern humans.

Analysis of the status of drug treatment in 746 inpatients with early-onset schizophrenia in China: a retrospective study

BACKGROUND

There is limited evidence on the use of antipsychotics in patients with early-onset schizophrenia, which lags significantly behind the studies on adult patients' medication and has a large disparity from actual clinical needs. Hence, this study aims to analyse the status of the drug use and its changes for patients with early-onset schizophrenia in our ward and to provide references on clinical medications for children and adolescents with schizophrenia.

METHODS

The distribution of antipsychotics on the day of discharge and their changes over time were retrospectively analysed in our inpatient department from March 2012 to July 2019. Descriptive statistical methods and χ2 tests were carried out.

RESULTS

A total of 746 inpatients with early-onset schizophrenia were included. Among them, 99.3% of patients were prescribed atypical antipsychotic drugs, with 5.5% of patients prescribed typical antipsychotic drugs. The top five most commonly used antipsychotics were aripiprazole, olanzapine, risperidone, paliperidone and clozapine. Olanzapine and risperidone were used more frequently in men (P < 0.01), whereas aripiprazole was used less frequently (P < 0.01). Olanzapine and paliperidone were used more frequently in patients with adolescent-onset schizophrenia (AOS) (P < 0.05), and risperidone was used more frequently in patients with child-onset schizophrenia (COS) (P < 0.01). Multiple antipsychotics during hospitalization were prescribed in 23.1% of patients. The combination of aripiprazole and olanzapine was the most common in the AOS group, and the combination of risperidone and clozapine was the most common in the COS group. Before and after approval by the competent Chinese authorities, the use of paliperidone and aripiprazole tended to be stable.

CONCLUSION

Atypical antipsychotics have been increasingly valued and used clinically. The consideration of medications for patients with early-onset schizophrenia needs to include factors such as age, sex, and severity of illness, metabolism and cognitive function at baseline.

Effects of Discontinuation of Drugs Used for Augmentation Therapy on Treatment Outcomes in Depression: A Systematic Review and Meta-analysis

INTRODUCTION

There has been no consensus on whether and how long add-on drugs for augmentation therapy should be continued in the treatment of depression.

METHODS

Double-blind randomized controlled trials that examined the effects of discontinuation of drugs used for augmentation on treatment outcomes in patients with depression were identified. Meta-analyses were performed to compare rates of study withdrawal due to any reason, study-defined relapse, and adverse events between patients who continued augmentation therapy and those who discontinued it.

RESULTS

Seven studies were included (n=841 for continuing augmentation therapy; n=831 for discontinuing augmentation therapy). The rate of study withdrawal due to any reason was not significantly different between the 2 groups (risk ratio [RR]=0.86, 95% confidence interval [CI]=0.69-1.08, p=0.20). Study withdrawal due to relapse was less frequent in the continuation group than in the discontinuation group (RR=0.61, 95% CI=0.40-0.92, p=0.02); however, this statistical significance disappeared when one study using esketamine as augmentation was excluded. Analysis of the data from 5 studies that included a stabilization period before randomization found less frequent relapse in the continuation group than in the discontinuation group (RR=0.47, 95% CI=0.36-0.60, p<0.01). This finding was repeated when the esketamine study was excluded.

DISCUSSION

No firm conclusions could be drawn in light of the small number of studies included. Currently available evidence suggests that add-on drugs, other than esketamine, used for augmentation therapy for depression may be discontinued. This may not be the case for patients who are maintained with augmentation therapy after remission.

Continuous versus extended antipsychotic dosing in schizophrenia: Less is more

Antipsychotic drugs temper psychotic symptoms by interacting with dopamine D2 receptors to reduce dopamine neurotransmission. Currently, the standard of care involves antipsychotic treatment protocols that achieve steady-state levels of medication. Maintaining patients on continuous treatment is thought to be necessary to keep them stabilised. However, continuous antipsychotic exposure increases the risk of adverse effects over time. These effects include metabolic and cardiovascular disorders, extrapyramidal complications, and dopamine receptor supersensitivity, the latter of which could potentially promote both treatment tolerance and psychosis relapse. In the present review, we describe evidence showing that continuous exposure to antipsychotic drugs can not only worsen long-term outcome, but-past acute phase treatment-it is also unnecessary to effectively manage schizophrenia symptoms. We also describe evidence that regular but extended dosing, allowing predictable periods of lower antipsychotic levels/D2 occupancy, is both safe and effective in patients, and it greatly reduces drug exposure overall. Studies in laboratory animals show that compared to continuous antipsychotic exposure, regular but extended dosing actually has superior antipsychotic-like efficacy, and it also substantially reduces the likelihood of both motor side effects and dopamine receptor supersensitivity. We propose that regular, but extended dosing should be considered in the long-term treatment of people with schizophrenia, because the available evidence suggests it can be just as effective as continuous treatment, while decreasing overall drug exposure and potentially reducing harmful side effects.

Effects of various antipsychotics on driving-related cognitive performance in adults with schizophrenia

The aim of this study was to determine whether the driving-related cognitive performance differs among adults with schizophrenia taking different types of antipsychotics. Neurocognitive performance was assessed using the Cognitive Perceptual Assessment for Driving (CPAD), a computerized battery of tests of visual perception, attention, working memory, reaction time, and inhibitory control for driving ability. One hundred and two adults with schizophrenia who were on antipsychotic monotherapy participated in the study. Of these, 15 were on haloperidol, 28 on risperidone, 14 on olanzapine, 28 on aripiprazole, and 17 on paliperidone. Sixty-four (63%) of the 102 subjects were regarded as competent to drive. Of the subjects taking haloperidol, 33% passed the CPAD, while the passing rates of subjects taking risperidone, olanzapine, aripiprazole, and paliperidone were 57%, 57%, 75%, and 82%, respectively, with a significant difference between the haloperidol and aripiprazole groups (p = 0.005) and between the haloperidol and paliperidone groups (p = 0.001). Additionally, scores on CPAD depth perception (number of correct responses), divided attention, digit span test, and trail-making test B subtests were significantly better for the aripiprazole and paliperidone groups than for the haloperidol and risperidone groups. In this cross-sectional design study, adults with schizophrenia treated with aripiprazole or paliperidone antipsychotic monotherapy demonstrated superior driving-related cognitive performance than those treated with haloperidol or risperidone antipsychotic monotherapy.

Does antipsychotic combination therapy reduce the risk of hospitalization in schizophrenia?

INTRODUCTION

: Despite treatment with antipsychotic medication, approximately 1/3 of individuals with schizophrenia will fail to have an adequate response. To treat these patients, a commonly utilized approach is antipsychotic combination therapy. Antipsychotic combination therapy is controversial with mixed efficacy and tolerability results. It is also unclear if antipsychotic combination therapy reduces or increases the risk of psychiatric hospitalization.

AREAS COVERED

: The authors review the prevalence, efficacy and tolerability concerns, and rationale behind antipsychotic combination therapy. Evidence comparing antipsychotic monotherapy vs polypharmacy using hospitalization as an outcome measure is summarized.

EXPERT OPINION

: Psychiatric rehospitalization is a useful measure of treatment effectiveness, incorporating aspects of treatment efficacy and tolerability. The evidence comparing the impact of antipsychotic monotherapy vs combination therapy on rehospitalization is mixed. Evidence is primarily retrospective in nature, and there is high heterogeneity between studies, which could partially explain the mixed results. There is likely a subset of patients for whom antipsychotic combination therapy reduces the risk of hospitalization greater than antipsychotic monotherapy. Patients should be treated individually taking into account their specific pattern of response.

Chronic smoking and cognition in patients with schizophrenia: A meta-analysis

BACKGROUND

Patients with schizophrenia display a very high rate of smoking in comparison with the general population. The aim of the present meta-analysis was to assess the association between cognitive performances and smoking status in patients with schizophrenia.

METHODS

This review was registered at PROSPERO, number CRD42019126758. After a systematic search on MEDLINE, PsycINFO, and clinicaltrials.gov databases, all studies measuring neurocognitive performances in both smoking and nonsmoking patients with a diagnosis of schizophrenia were included. Original data were extracted. Standardized mean differences (SMD) were calculated with the means and standard deviations extracted using a random-effect model. Cognitive performances were compared between smoking and nonsmoking patients with schizophrenia. Meta-regressions were performed to explore the influence of sociodemographic and clinical variables on SMD.

RESULTS

Eighteen studies were included in this meta-analysis. Chronic smoking in patients with schizophrenia, compared to nonsmoking, was associated with a significant more important impairment in attention (p = 0.02), working memory (p < 0.001), learning (p < 0.001), executive function (EF) reasoning/problem solving (p < 0.001) and speed of processing (p < 0.001), but not in delayed memory, EF abstraction/shifting, EF inhibition and language. The meta-regression analysis found that attention impairment could be influenced by age (p < 0.001) and Positive and Negative Syndrome Scale (PANSS) total score (p = 0.006).

CONCLUSIONS

This meta-analysis provides strong evidence that, in patients with schizophrenia, chronic smoking is related to cognitive impairment. This association emphasizes the importance of paying careful attention to both tobacco addiction and cognitive functioning in patients with schizophrenia.

Up-to-date expert opinion on the safety of recently developed antipsychotics

Introduction There are several new and emerging antipsychotic medication strategies recently marketed or under clinical development for the treatment of several mental disorders. There is the need to provide an up-to-date overview on the safety of this new generation of antipsychotic medications, which includes also the third-generation antipsychotics (TGA). Areas covered The authors aimed at providing a synthesis of the most current evidence about the safety profile of the recently developed and/or marketed antipsychotics. Qualitative synthesis followed an electronic search made inquiring of the following databases: MEDLINE, Embase, PsycINFO, and the Cochrane Library from inception until March 2020, combining free terms and MESH headings for the topics of TGA and recently developed and/or marketed antipsychotics as following: ((safety OR adverse events OR side effects) AND ((brexpiprazole OR cariprazine OR inhaled loxapine OR lumateperone (ITI-007) OR lurasidone OR pimavanserin OR roluperidone (MIN-101) OR transdermal patch asenapine)). Expert opinion Overall, newer antipsychotics display a good safety profile, with a well-demonstrated lower metabolic liability compared to second-generation antipsychotics. Furthermore, TGA appear to specifically target negative symptomatology and improving cognitive domains. Abbreviations Aps=Antipsychotic Drugs; AEs = Adverse Effects; EPS = Extrapyramidal Symptoms; NMS = Neuroleptic malignant syndrome; D = Dopamine; K_i = Inhibitory Constant; 5-HT = Serotonin; ECG = Electrocardiogram; H = Histamine; M = Muscarinic; BMI = Body Mass Index.

Association between cognition and suicidal ideation in patients with major depressive disorder: A longitudinal study

BACKGROUND

Suicidal ideation (SI) is common in patients with major depressive disorder (MDD) and often related to cognitive deficits. Limited longitudinal study has shown that cognitive improvement is associated with reduced SI. However, the comparatively study in Chinese depressed patients is still absent. The objective of this study was to explore the specific cognitive deficits in Chinese MDD with SI and investigate the relationship between changes in cognition and change in SI across antidepressant treatment.

METHODS

Three hundred and five patients with MDD received four weeks of antidepressant treatment. The 17-item Hamilton Depression Rating Scale (HAMD-17) and four domains of the MATRICS Consensus Cognitive Battery (MCCB), including speed of processing, working memory, visual learning and verbal learning were measured at baseline and four-week follow-up.

RESULTS

One hundred and thirty patients (42.6%) expressed suicidal ideation. Suicidal patients performed worse on verbal learning than non-suicidal patients. Change in speed of processing domain was negatively associated with change in suicidal scores over time. Logistic regression analysis showed that reduction of SI was associated with improvement of speed of processing.

LIMITATION

The major limitation was that there was no healthy control group in the current study, which might limit the interpretation of cognitive deficits in depressed patients with SI.

CONCLUSIONS

Our findings suggest that suicidal patients performed worse on verbal learning which can potentially serve as a cognitive biomarker of suicide risk in MDD. Moreover, reduced suicidal ideation was associated with improved speed of processing.

Subcortical Dopamine and Cognition in Schizophrenia: Looking Beyond Psychosis in Preclinical Models

Schizophrenia is characterized by positive, negative and cognitive symptoms. All current antipsychotic treatments feature dopamine-receptor antagonism that is relatively effective at addressing the psychotic (positive) symptoms of schizophrenia. However, there is no clear evidence that these medications improve the negative or cognitive symptoms, which are the greatest predictors of functional outcomes. One of the most robust pathophysiological observations in patients with schizophrenia is increased subcortical dopamine neurotransmission, primarily in the associative striatum. This brain area has an important role in a range of cognitive processes. Dopamine is also known to play a major part in regulating a number of cognitive functions impaired in schizophrenia but much of this research has been focused on cortical dopamine. Emerging research highlights the strong influence subcortical dopamine has on a range of cognitive domains, including attention, reward learning, goal-directed action and decision-making. Nonetheless, the precise role of the associative striatum in the cognitive impairments observed in schizophrenia remains poorly understood, presenting an opportunity to revisit its contribution to schizophrenia. Without a better understanding of the mechanisms underlying cognitive dysfunction, treatment development remains at a standstill. For this reason, improved preclinical animal models are needed if we are to understand the complex relationship between subcortical dopamine and cognition. A range of new techniques are facillitating the discrete manipulation of dopaminergic neurotransmission and measurements of cognitive performance, which can be investigated using a variety of sensitive translatable tasks. This has the potential to aid the successful incorporation of recent clinical research to address the lack of treatment strategies for cognitive symptoms in schizophrenia. This review will give an overview on the current state of research focused on subcortical dopamine and cognition in the context of schizophrenia research. We also discuss future strategies and approaches aimed at improving the translational outcomes for the treatment of cognitive deficits in schizophrenia.

Comparative Tolerability of Dopamine D2/3 Receptor Partial Agonists for Schizophrenia

Aripiprazole, brexpiprazole and cariprazine differ from all other second-generation antipsychotics due to partial agonism at the dopamine D2 and D3 receptors. In contrast to aripiprazole, brexpiprazole has lower intrinsic dopamine D2 activity and higher affinity for the serotonin 5-HT1A and 5-HT2A receptors, while cariprazine has the highest affinity for the dopamine D3 receptor, and the longest half-life. The main adverse effect of dopamine receptor partial agonists (DRPAs) is akathisia of low-to-moderate severity, which occurs in a small proportion of patients, usually in the first few weeks of treatment. While definitive conclusions concerning differences between the DRPAs require head-to-head comparison studies, on the available evidence, akathisia is probably least likely to occur with brexpiprazole and most likely with cariprazine; the risk of akathisia with aripiprazole lies in between. Weight-gain risk is low with aripiprazole and cariprazine, but moderate with brexpiprazole. Risk of sedation is low with DRPAs, as is risk of insomnia and nausea. Partial dopamine agonism leads to a low risk for hyperprolactinaemia (and probably a low risk of sexual dysfunction). Prolactin concentrations fall in some patients (particularly those with elevated levels prior to initiating the drugs). Rates of discontinuation due to adverse effects in pivotal studies were low, and on the whole, DRPAs are well tolerated. Aripiprazole has been implicated in pathological gambling and other impulse control behaviours, likely due to partial dopamine agonist activity (there have been no reports with brexpiprazole and cariprazine). The risks for diabetes and tardive dyskinesia with DRPAs are unknown, but are likely to be low. On the basis of tolerability, DRPAs should be considered as first-line treatment options, particularly in patients with early schizophrenia.

Dopamine D2 Receptor Occupancy Estimated From Plasma Concentrations of Four Different Antipsychotics and the Subjective Experience of Physical and Mental Well-Being in Schizophrenia: Results From the Randomized NeSSy Trial

BACKGROUND

Impaired subjective well-being in schizophrenia patients treated with antipsychotics has often been linked inter alia to the antidopaminergic effects of medication. Thus, it is important to capture the association between striatal dopamine D2 receptor occupancy (D2-RO) and global subjective well-being. We examined this association using data from our multicenter, randomized, double-blind Neuroleptic Strategy Study (NeSSy).

METHODS

An innovative double randomization process was used for allocation of patients to the specific treatment groups. Plasma drug concentrations were measured after 6 and 24 weeks of treatment to obtain the estimated D2-RO (eD2-RO) relative to literature values. We made an exploratory analysis of associations between eD2-RO and subjective well-being scores. One hundred two blood samples from 69 patients were available for the analysis. Because of the lack of a satisfactory occupancy model for quetiapine, only haloperidol, flupentixol, and olanzapine treatment groups were pooled, whereas aripiprazole data were analyzed separately, because of its partial agonistic properties.

RESULTS

In the pooled antagonist group, eD2-RO correlated negatively with the summarized well-being score. In a more detailed analysis, this association could be confirmed for all first-generation antipsychotic-treated patients, but not for the separate second-generation antipsychotic groups. In the aripiprazole group, higher eD2-RO was associated with impaired physical well-being, but had no association with mental well-being.

CONCLUSIONS

Our results suggest that high plasma levels and consequently high occupancy at D2 receptors are disadvantageous for subjective well-being, as distinct from the objective extrapyramidal side effects. To minimize patients' malaise, which disfavors adherence, implementation of therapeutic drug monitoring in the clinical routine may be useful.

Factors associated with successful antipsychotic dose reduction in schizophrenia: a systematic review of prospective clinical trials and meta-analysis of randomized controlled trials

This systematic review and meta-analysis examined predictors of successful antipsychotic dose reduction in schizophrenia. Prospective clinical trials and randomized controlled trials (RCTs) investigating antipsychotic dose reduction in schizophrenia were selected for systematic review and meta-analysis, respectively. In total, 37 trials were identified. Only 8 studies focused on second-generation antipsychotics (SGAs); no studies investigated long-acting injectable SGAs. Of 24 studies evaluating relapse or symptom changes, 20 (83.3%) met the criteria for successful dose reduction. Factors associated with successful dose reduction were study duration < 1 year, age > 40 years, duration of illness > 10 years, and post-reduction chlorpromazine equivalent (CPZE) dose > 200 mg/day. Clinical deterioration was mostly re-stabilized by increasing the dose to the baseline level (N = 7/8, 87.5%). A meta-analysis of 18 RCTs revealed that relapse rate was significantly higher in the reduction group than the maintenance group (risk ratio [RR] = 1.96; 95% confidence interval [CI], 1.23-3.12), whereas neurocognition was significantly improved (standardized mean difference = 0.69; 95% CI, 0.25-1.12). A subgroup analysis indicated that only a post-reduction CPZE dose ≤ 200 mg/day was associated with an increased risk of relapse (RR = 2.79; 95% CI, 1.29-6.03). Thus, when reducing antipsychotic doses, clinicians should consider the long-term risk of relapse in younger patients with a relatively short illness duration and keep the final doses higher than CPZE 200 mg/day. Further studies, particularly those involving SGAs, are warranted to determine the optimal strategies for successful antipsychotic dose reduction in schizophrenia.

Association of regulatory variants of dopamine β-hydroxylase with cognition and tardive dyskinesia in schizophrenia subjects

BACKGROUND

Dopamine-β-hydroxylase (DBH, EC 1.14.17.1), which converts dopamine to norepinephrine, is a candidate gene in neuropsychiatric diseases.

AIM

To assess the effect of regulatory variants in DBH on schizophrenia and its endophenotypes -cognition and tardive dyskinesia.

METHODS

We tested association of functional variants 19bp Ins/Del, rs1989787 and rs1611115 in DBH with i) schizophrenia (1236 cases, 1136 controls), ii) tardive dyskinesia (83 positive, 162 negative) and iii) performance functions of cognition (357 cases, 306 controls) estimated by the Penn Computerized Neurocognitive Battery.

RESULTS

A modest haplotypic (Ins-C; 19bp Ins/Del - rs1989787 C>T; p=0.04) association was observed with schizophrenia. We observed ~39% reduction in activity of 19bp Del allele on luciferase assay. Analysis of covariance revealed interactions of tardive dyskinesia status and: i) 19bp Ins/Del (genotypic, p=0.04) and ii) rs1989787 and rs1611115 (combined genotypic, p=0.004) on Abnormal Involuntary Movement Scale total score. Association of rs1611115 with positive and negative syndrome scale (PANSS) total score (p=0.05) and allelic/genotypic association with lower positive (p=0.03/0.04), general psychopathology (p=0.01/0.01) PANSS scales in tardive dyskinesia-positive; and allelic/genotypic (p=0.02/0.05) with higher score of depressive factors in tardive dyskinesia-negative subgroups were observed. Analysis of covariance with continuous variable of cognition showed interaction of health status with: i) rs1989787 on accuracy and efficiency (p=0.03) of abstraction and mental flexibility; ii) rs1611115 on accuracy of working memory and emotion (p=0.05); iii) 19bp Ins/Del on processing speed of emotion (p=0.03). Allelic/genotypic association of rs1989787 with spatial ability (p=0.02-0.05) among healthy controls; association of rs1611115 with Global Assessment Scale scores in the past month (p=0.05) among schizophrenia subjects of cognition cohort was also observed.

CONCLUSIONS

With modest genotype-phenotype correlations available for DBH variants, personalized treatment regimens based on DBH activity for ameliorating tardive dyskinesia and cognitive symptoms may be plausible.

Model-Guided Antipsychotic Dose Reduction in Schizophrenia: A Pilot, Single-Blind Randomized Controlled Trial

PURPOSE/BACKGROUND

Patients with schizophrenia as well as their psychiatrists are hesitant to reduce the antipsychotic dose in fear of relapse. To overcome such dilemmas, we developed models to individually calculate an oral dose that corresponds to a given target dopamine D2 receptor occupancy.

METHODS/PROCEDURES

In this pilot, 52-week single-blind randomized controlled trial, 35 clinically stable patients with schizophrenia receiving either risperidone or olanzapine monotherapy were randomly assigned to dose reduction (n = 17) or dose maintenance group (n = 18). In the former group, baseline doses were reduced to the doses corresponding to 65% D2 occupancy (the lower end of therapeutic window) at trough that were calculated from randomly collected plasma concentrations using our models.

FINDINGS/RESULTS

In the dose reduction group, doses of risperidone and olanzapine were decreased from 4.2 ± 1.9 to 1.4 ± 0.4 and 12.8 ± 3.9 to 6.7 ± 1.8 mg/d, whereas the doses in the dose maintenance group were 4.3 ± 1.9 and 15.8 ± 4.6 mg/d, respectively. Twelve subjects (70.5%) and 13 subjects (72.2%) in the dose reduction and dose maintenance groups completed the study (P = 0.604), whereas 3 subjects (18.8%) and none dropped out because of clinical worsening in the dose reduction and dose maintenance groups, respectively. There were not significant differences in score changes in Positive and Negative Syndrome Scale between the 2 groups but in Positive subscale scores in the Clinical Global Impression-Schizophrenia (0.4 ± 0.7 in the dose reduction group vs -0.1 ± 0.7 in the dose maintenance group, P = 0.029).

IMPLICATIONS/CONCLUSIONS

Although our model-guided dose reduction strategy was found to be comparable with no-dose change in terms of dropout rates, safety issues have to be further examined.

The Factors Affecting the Relationship between Remission Status and Employment in Chronic Schizophrenia Patients

OBJECTIVE

Symptomatic remission have substantial effects in long-term schizophrenia outcome, but exact determinants of the employment. In this study, the relationship between employment and symptomatic remission in chronic schizophrenia patients and other factors related to employment were investigated.

METHODS

100 patients interviewed were evaluated by the Positive and Negative Syndrome Scale (PANSS), Functional Recovery Scale in Schizophrenia (FROGS), Global Assessment of Functioning (GAF), Quality of Life Scale (QoL) and Subjective Recovery Assessment Scale (SubRAS). Sociodemographic variables, clinical features, antipsychotic dose and past working history obtained from patient interviews were investigated.

RESULTS

The patients of 40% who participate in the study were symptomatic remission, but only 53.5% of these patients weren't employed. Young age, especially, -regardless of the onset of illness- working a job in the past, low and moderate use CPED (equivalent doses according to chlorpromazine), shorter disease duration, symptomatic remission was found to be closely related to employment. While QoL, FROGS, GAF, and SubRAS total scores of employment group were higher than the unemployment group, PANSS total scores in the unemployment group were higher than that of the employment group. There was a high correlation between the scales and employment status.

CONCLUSION

Employment status was closely related with the remission status. This study supports that symptomatic remission alone is not decisive for employment. It was found that younger age, past working history (before or after the disease), low and intermediate CPED antipsychotic use and shorter duration of disease were closely related to employment with symptomatic remission.

Nicotine consumption during the prodromal phase of schizophrenia - a review of the literature

Recent research has fueled a debate concerning the role of nicotine in the emergence of schizophrenia. The three main hypotheses are: (a) the self-medication effect, (b) the causal relationship hypothesis, or (c) the shared diathesis hypothesis. To explore this role, the study of nicotine consumption during the initial prodromal phase of schizophrenia offers important opportunities. In the present work, 10 relevant studies are reviewed, out of 727 retrieved citations, in order to address questions regarding the prevalence of smoking in the prodromal period, the time of smoking initiation, existing patterns of tobacco use in relation with the escalation of prodromal symptoms into first psychotic episode, and potential differences in symptomatology between smokers and nonsmokers. Even though there was considerable heterogeneity among studies, relevant findings are discussed. Prevalence of nicotine use during the prodromal period was reported to be 16.6-46%. Tobacco use was found to be taken up most often before or during the prodromal period of schizophrenia. Even though a protective role of smoking has been reported by one study, other studies report an increased risk for psychosis, with hazard ratios 2.77 (95% CI: 2.34-3.43) and 2.21 (95% CI: 1.11-4.42) for female and male heavy smokers (11-20 and >20 cigarettes/day), respectively. In a different study, the risk of onset was associated with the progressive use of cannabis and tobacco prior to onset, particularly with rapid escalation to the highest levels of use. Also, nicotine use in ultra high risk (UHR) for developing psychosis subjects is associated with elevated cognitive performance, namely better processing speed, visual learning, and spatial working memory. As a conclusion, it appears that evidence accumulates supporting a possible etiologic role of smoking, in the emergence of schizophrenia along with diverse effects on patients' symptomatology, already demonstrable at the prodromal phase. Future research employing better-defined criteria should further explore the patterns of use and effects of nicotine during the schizophrenia prodrome.

Cognitive impairment in psychotic illness: prevalence, profile of impairment, developmental course, and treatment considerations

Despite effective pharmacological treatments for psychotic symptoms (eg, hallucinations, delusions), functional outcomes for people with psychotic disorders are often disappointing. Although it is not included in the diagnostic criteria for psychotic disorders, cognitive impairment is one of the strongest determinants of community functioning in this clinical population, and thus it is an important target for intervention. In this review, we discuss the major areas of research regarding impaired cognition in psychotic illness. The specific topics covered include: (i) the prevalence of cognitive impairment in psychotic disorders; (ii) the profile and magnitude of cognitive impairment in psychotic disorders; (iii) the developmental course of cognitive impairment; (iv) the longitudinal stability of cognitive impairment; and (v) treatment approaches to improve cognitive performance in people with psychotic disorders.
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