The neurobiology of relapse in schizophrenia

Towards Enhancing Drug Development Methodology to Treat Cognitive Impairment Associated With Schizophrenia and Other Neuropsychiatric Conditions: Insights From 2 Decades of Clinical Trials

Cognitive impairment is a core feature and leading cause of functional disability in schizophrenia and other neuropsychiatric disorders. The Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) initiative in the early 2000s marked a pivotal moment for drug development, establishing consensus on methodology for treatment studies, including assessment strategies and trial designs, for cognitive impairment associated with schizophrenia (CIAS). Despite extensive industry-sponsored and academic drug development efforts over the last 2 decades using these strategies no pharmacological treatments have been approved for CIAS. Drawing on pharmaceutical industry experience and scientific developments since the MATRICS initiative, we review lessons learned about the practical and operational complexities of conducting large-scale CIAS clinical trials. Based on this collective experience, we identify elements of the MATRICS guidelines that may warrant reconsideration and suggest some new approaches to streamline the drug development pathway, without weakening standards for evidence. Our goal is to initiate an open exchange among all stakeholders about possible enhancements to drug development methodology that optimize our ability to develop new treatments for cognitive impairment in schizophrenia and other neuropsychiatric disorders.

Current emerging therapeutic targets and clinical investigational agents for schizophrenia: Challenges and opportunities

Since the first discovery of antipsychotics in the 1950s, targeting dopaminergic drugs has manifested to well manage the positive symptoms of schizophrenia with limited efficacy for the negative and cognitive symptoms. In past decades, extensive efforts have been undertaken towards the development of innovative agents that can effectively stabilize the dopamine and serotonin systems or target to nondopaminergic pathways, leading to various promising drug candidates entering into clinical trials. Notably, the sigma-2, 5-HT2A, and α1A receptor antagonist roluperidone, as well as a fixed-dose combination of the M1/4 receptor agonist KarXT, have been submitted for NDA applications. The dual agonist ulotaront, which targets TAAR1 and 5-HT1A receptors, and the GlyT1 inhibitor iclepertin have advanced into phase 3 clinical trials. Nevertheless, satisfactory therapeutic strategies for schizophrenia remain elusive. This review highlights current clinical endeavors in developing novel chemical small-molecule entities and fixed-dose combinations for the treatment of schizophrenia since 2017, thus facilitating the efficient development of the next generation of antipsychotics.

Behind the heterogeneity in the long-term course of first-episode psychosis: Different psychotic symptom trajectories are associated with different patterns of cannabis and stimulant use

BACKGROUND

Data-driven classification of long-term psychotic symptom trajectories and identification of associated risk factors could assist treatment planning and improve long-term outcomes in psychosis. However, few studies have used this approach, and knowledge about underlying mechanisms is limited. Here, we identify long-term psychotic symptom trajectories and investigate the role of illness-concurrent cannabis and stimulant use.

METHODS

192 participants with first-episode psychosis were followed up after 10 years. Psychotic symptom trajectories were estimated using growth mixture modeling and tested for associations with baseline characteristics and cannabis and stimulant use during the follow-up (FU) period.

RESULTS

Four trajectories emerged: (1) Stable Psychotic Remission (54.2 %), (2) Delayed Psychotic Remission (15.6 %), (3) Psychotic Relapse (7.8 %), (4) Persistent Psychotic Symptoms (22.4 %). At baseline, all unfavorable trajectories (2-4) were characterized by more schizophrenia diagnoses, higher symptom severity, and longer duration of untreated psychosis. Compared to the Stable Psychotic Remission trajectory, unstable trajectories (2,3) showed distinct associations with cannabis/stimulant use during the FU-period, with dose-dependent effects for cannabis but not stimulants (Delayed Psychotic Remission: higher rates of frequent cannabis and stimulant use during the first 5 FU-years; Psychotic Relapse: higher rates of sporadic stimulant use throughout the entire FU-period). The Persistent Psychosis trajectory was less clearly linked to substance use during the FU-period.

CONCLUSIONS

The risk for an adverse long-term course could be mitigated by treatment of substance use, where particular attention should be devoted to preventing the use of stimulants while the use reduction of cannabis may already yield positive effects.

Gamma-aminobutyric acid supplementation improves olanzapine-induced insulin resistance by inhibiting macrophage infiltration in mice subcutaneous adipose tissue

AIMS

To investigate whether gamma-aminobutyric acid (GABA) supplementation improves insulin resistance during olanzapine treatment in mice and to explore the underlying mechanisms.

MATERIALS AND METHODS

Insulin resistance and body weight gain were induced in mice by 10 weeks of olanzapine treatment. Simultaneously, the mice were administered GABA after 4 weeks of olanzapine administration.

RESULTS

We found that mice treated with olanzapine had lower GABA levels in serum and subcutaneous white adipose tissue (sWAT). GABA supplementation restored GABA levels and improved olanzapine-induced lipid metabolism disorders and insulin resistance. Chronic inflammation in adipose tissue is one of the main contributors to insulin resistance. We found that GABA supplementation inhibited olanzapine-induced adipose tissue macrophage infiltration and M1-like polarization, especially in sWAT. In vitro studies showed that stromal vascular cells, rather than adipocytes, were sensitive to GABA. Furthermore, the results suggested that GABA improves olanzapine-induced insulin resistance at least in part through a GABAB receptor-dependent pathway.

CONCLUSIONS

These findings suggest that targeting GABA may be a potential therapeutic approach for olanzapine-induced metabolic disorders.

GDNF and miRNA-29a as biomarkers in the first episode of psychosis: uncovering associations with psychosocial factors

Aim

Schizophrenia involves complex interactions between biological and environmental factors, including childhood trauma, cognitive impairments, and premorbid adjustment. Predicting its severity and progression remains challenging. Biomarkers like glial cell line-derived neurotrophic factor (GDNF) and miRNA-29a may bridge biological and environmental aspects. The goal was to explore the connections between miRNAs and neural proteins and cognitive functioning, childhood trauma, and premorbid adjustment in the first episode of psychosis (FEP).

Method

This study included 19 FEP patients who underwent clinical evaluation with: the Childhood Trauma Questionnaire (CTQ), the Premorbid Adjustment Scale (PAS), the Positive and Negative Syndrome Scale (PANSS), and the Montreal Cognitive Assessment Scale (MoCA). Multiplex assays for plasma proteins were conducted with Luminex xMAP technology. Additionally, miRNA levels were quantitatively determined through RNA extraction, cDNA synthesis, and RT-qPCR on a 7500 Fast Real-Time PCR System.

Results

Among miRNAs, only miR-29a-3p exhibited a significant correlation with PAS-C scores (r = -0.513, p = 0.025) and cognitive improvement (r = -0.505, p = 0.033). Among the analyzed proteins, only GDNF showed correlations with MoCA scores at the baseline and after 3 months (r = 0.533, p = 0.0189 and r = 0.598, p = 0.007), cognitive improvement (r = 0.511, p = 0.025), and CTQ subtests. MIF concentrations correlated with the PAS-C subscale (r = -0.5670, p = 0.011).

Conclusion

GDNF and miR-29a-3p are promising as biomarkers for understanding and addressing cognitive deficits in psychosis. This study links miRNA and MIF to premorbid adjustment and reveals GDNF's unique role in connection with childhood trauma.

Working memory deterioration as an early warning sign for relapse in remitted psychosis: A one-year naturalistic follow-up study

BACKGROUND

Relapse prevention is an important goal in the clinical management of psychosis. Cognitive deficits/deterioration can provide useful insights for monitoring relapse in psychosis patients.

METHODS

This was a prospective, naturalistic 1-year follow-up study involving 110 psychosis patients with full clinical remission. Relapse, defined as the recurrence of psychotic symptoms, was monitored monthly along with digital tracking of verbal and visual working memory using a mobile app developed for this study. Cognitive deterioration was defined as worsening performance over 2 months prior to relapse or study termination, whichever was earlier. Other clinical, cognitive, functioning, and psychosocial variables were also collected.

RESULTS

At 1 year, 18 (16.36%) patients relapsed, of which 6 (33.33%) required hospitalization. Relapse was predicted by verbal working memory deterioration 2 months prior to relapse (p = 0.029), worse medication adherence (p = 0.018), and less resilience (p = 0.014).

CONCLUSIONS

Verbal working memory deterioration is a novel early sign of relapse. It is a clearly defined, objectively measurable, and reproducible marker that can help clinicians and healthcare workers identify patients at risk of relapse and make decisions about maintenance therapy. Moreover, digital monitoring is a viable tool in the management of relapse.

Neurobiology of Schizophrenia: A Comprehensive Review

Schizophrenia is a debilitating disease that presents with both positive and negative symptoms affecting cognition and emotions. Extensive studies have analyzed the different factors that contribute to the disorder. There is evidence of significant genetic etiology involving multiple genes such as dystrobrevin binding protein 1 (DTNBP1) and neuregulin 1 (NRG1). There is no clear link between neurotransmitter changes and the pathophysiology of schizophrenia; however, studies have shown that subcortical dopamine dysfunction is the key mechanism. Specific regions of gray and white matter changes are observed in patients with schizophrenia; gray matter changes being more significant after the onset of psychosis. These pathological changes may be implicated in the impairment of executive functioning, attention, and working memory. The disease can be managed with pharmacological treatments based on individual patient profile, patient compliance, and disease severity. The challenge of disease management sometimes persists due to the side effects. A better understanding of the pathological processes in schizophrenia may lead to more specific and effective therapies.

Increased brain gyrification and subsequent relapse in patients with first-episode schizophrenia

Most schizophrenia patients experience psychotic relapses, which may compromise long-term outcome. However, it is difficult to objectively assess the actual risk of relapse for each patient as the biological changes underlying relapse remain unknown. The present study used magnetic resonance imaging (MRI) to investigate the relationship between brain gyrification pattern and subsequent relapse in patients with first-episode schizophrenia. The subjects consisted of 19 patients with and 33 patients without relapse during a 3-year clinical follow-up after baseline MRI scanning. Using FreeSurfer software, we compared the local gyrification index (LGI) between the relapsed and non-relapsed groups. In the relapsed group, we also explored the relationship among LGI and the number of relapses and time to first relapse after MRI scanning. Relapsed patients exhibited a significantly higher LGI in the bilateral parietal and left occipital areas than non-relapsed patients. In addition, the time to first relapse was negatively correlated with LGI in the right inferior temporal cortex. These findings suggest that increased LGI in the temporo-parieto-occipital regions in first-episode schizophrenia patients may be a potential prognostic biomarker that reflects relapse susceptibility in the early course of the illness.

A longitudinal study of gene expression in first-episode schizophrenia; exploring relapse mechanisms by co-expression analysis in peripheral blood

Little is known about the pathophysiological mechanisms of relapse in first-episode schizophrenia, which limits the study of potential biomarkers. To explore relapse mechanisms and identify potential biomarkers for relapse prediction, we analyzed gene expression in peripheral blood in a cohort of first-episode schizophrenia patients with less than 5 years of evolution who had been evaluated over a 3-year follow-up period. A total of 91 participants of the 2EPs project formed the sample for baseline gene expression analysis. Of these, 67 provided biological samples at follow-up (36 after 3 years and 31 at relapse). Gene expression was assessed using the Clariom S Human Array. Weighted gene co-expression network analysis was applied to identify modules of co-expressed genes and to analyze their preservation after 3 years of follow-up or at relapse. Among the 25 modules identified, one module was semi-conserved at relapse (DarkTurquoise) and was enriched with risk genes for schizophrenia, showing a dysregulation of the TCF4 gene network in the module. Two modules were semi-conserved both at relapse and after 3 years of follow-up (DarkRed and DarkGrey) and were found to be biologically associated with protein modification and protein location processes. Higher expression of DarkRed genes was associated with higher risk of suffering a relapse and early appearance of relapse (p = 0.045). Our findings suggest that a dysregulation of the TCF4 network could be an important step in the biological process that leads to relapse and suggest that genes related to the ubiquitin proteosome system could be potential biomarkers of relapse.

Metabotropic glutamate receptors and nitric oxide in dopaminergic neurotoxicity

Dopaminergic neurotoxicity is characterized by damage and death of dopaminergic neurons. Parkinson's disease (PD) is a neurodegenerative disorder that primarily involves the loss of dopaminergic neurons in the substantia nigra. Therefore, the study of the mechanisms, as well as the search for new targets for the prevention and treatment of neurodegenerative diseases, is an important focus of modern neuroscience. PD is primarily caused by dysfunction of dopaminergic neurons; however, other neurotransmitter systems are also involved. Research reports have indicated that the glutamatergic system is involved in different pathological conditions, including dopaminergic neurotoxicity. Over the last two decades, the important functional interplay between dopaminergic and glutamatergic systems has stimulated interest in the possible role of metabotropic glutamate receptors (mGluRs) in the development of extrapyramidal disorders. However, the specific mechanisms driving these processes are presently unclear. The participation of the universal neuronal messenger nitric oxide (NO) in the mechanisms of dopaminergic neurotoxicity has attracted increased attention. The current paper aims to review the involvement of mGluRs and the contribution of NO to dopaminergic neurotoxicity. More precisely, we focused on studies conducted on the rotenone-induced PD model. This review is also an outline of our own results obtained using the method of electron paramagnetic resonance, which allows quantitation of NO radicals in brain structures.

Clinical outcomes of paliperidone long-acting injection in patients with schizophrenia: a 1-year retrospective cohort study

BACKGROUND

Schizophrenia is a severe psychiatric disorder. Poor medical adherence increases relapse rate. Long-acting injection of antipsychotic agent is developed for improving medical adherence. In this study, we examined the effect of paliperidone long-acting injection (PLAI) treatment in patients with schizophrenia in a real-world setting.

METHODS

In this retrospective cohort study, 467 patients with schizophrenia were enrolled, treated with risperidone PLAI or oral antipsychotics, and followed for 1 year. Concomitant medication, namely anticonvulsants, antidepressants, anxiolytics, sedatives or hypnotics, anticholinergics, and beta-blockers, were administered. Patients were classified into 2 groups: the LAI group (patients received LAI for treatment) and the NLAI group (patients taking only oral antipsychotics). The incidence of hospitalization, the length of hospitalization, and the incidence of emergency room visits were assessed.

RESULTS

The LAI group had a higher incidence of psychiatric acute ward admission (NLAI group = 4.8%; LAI = 30.3%) and emergency room visits (NLAI group = 7.3%; LAI group = 36.0%) before enrolment. During the one-year follow-up, the incidence of acute ward admission and emergency room visit did not differ in the NLAI group (P = .586 and .241) compared with before enrolment, whereas both incidences were significantly decreased in the LAI group (P < .0001 in both of them).

CONCLUSIONS

PLAI reduces the incidence of admission and emergency room visits.

Using a mobile health device to manage severe mental illness in the community: What is the potential and what are the challenges?

There has been a revolution in the use of mobile health devices for monitoring physical health. There is more recent interest in whether these devices can also be used for monitoring symptoms of mental illness. This paper considers how stress increases risk of mental deterioration and individuals with mental illness are sensitive to the effects of stress. It discusses how an inexpensive mobile health device could be used for detecting physiological signs of stress: deviations in biometrics such as sleep, activity and arousal may reflect a stress response and increased risk of relapse. These biometrics can allow patients to self-monitor and clinicians to detect early warning signs. This paper reviews the measurement of electrodermal activity, actigraphy and heart rate to predict mental deterioration. It considers the advantages of continuous measurement and reviews studies using mobile health devices to monitor stress and psychosis. It describes the potential for using a mobile health device to manage and monitor severe mental illness in young adults. Finally, this paper considers challenges associated with this approach, particularly with regard to correctly interpreting the physiological data and integrating the mobile health device into clinical practice. This paper concludes a mobile health device has the potential to enhance care by improving detection of early warning signs and increasing the connection between clinicians and their patients.

Lack of dopamine D4 receptor participation in mouse hyperdopaminergic locomotor response

Chronic methamphetamine (METH) treatment induces behavioral sensitization in rodents. During this process, hyperactivation of the mesolimbic dopamine system plays a central role, and dopamine D2-like receptor-based antipsychotics are known to alleviate the behavioral hyperactivity. The atypical antipsychotic, clozapine (Clz), acts partially as a dopamine D4 receptor (D4R) antagonist and mitigates hyperdopaminergic drug addiction and/or comorbid psychotic symptoms; however, it remains unclear whether D4R blockade contributes to the therapeutic effects of Clz. Here, we evaluated the potential role of D4R in regulating hyperdopaminergia-induced behavioral hyperactivity in METH behavioral sensitization and dopamine transporter (DAT) knockdown (KD) mice. Clz or a D4R-selective antagonist, L-745,870, were co-administered to mice with daily METH in a METH sensitization model, and Clz or L-745,870 were administered alone in a DAT KD hyperactivity model. Locomotor activity and accumbal D4R expression were analyzed. Clz suppressed both the initiation and expression of METH behavioral sensitization, as well as DAT KD hyperactivity. However, repetitive Clz treatment induced tolerance to the suppression effect on METH sensitization initiation. In contrast, D4R inhibition by L-745,870 had no effect on METH sensitization or DAT KD hyperactivity. Accumbal D4R expression was similar between METH-sensitized mice with and without Clz co-treatment. In sum, our results suggest the mesolimbic D4R does not participate in behavioral sensitization encoded by hyperdopaminergia, a finding which likely extends to the therapeutic effects of Clz. Therefore, molecular targets other than D4R should be prioritized in the development of future therapeutics for treatment of hyperdopaminergia-dependent neuropsychiatric disorders.

The COVID-19 Global Pandemic: Implications for People With Schizophrenia and Related Disorders

The coronavirus disease-19 (COVID-19) global pandemic has already had an unprecedented impact on populations around the world, and is anticipated to have a disproportionate burden on people with schizophrenia and related disorders. We discuss the implications of the COVID-19 global pandemic with respect to: (1) increased risk of infection and poor outcomes among people with schizophrenia, (2) anticipated adverse mental health consequences for people with schizophrenia, (3) considerations for mental health service delivery in inpatient and outpatient settings, and (4) potential impact on clinical research in schizophrenia. Recommendations emphasize rapid implementation of measures to both decrease the risk of COVID-19 transmission and maintain continuity of clinical care and research to preserve safety of both people with schizophrenia and the public.

Clozapine response trajectories and predictors of non-response in treatment-resistant schizophrenia: a chart review study

Although clozapine is the main antipsychotic medication for treatment-resistant schizophrenia, 40-70% of patients on clozapine have persistent psychotic symptoms (i.e. ultra-treatment-resistant schizophrenia, UTRS). We aimed to examine clozapine response/non-response patterns in patients with treatment-resistant schizophrenia, as well as determine patient clinico-demographic factors associated with long-term clozapine non-response. Clinico-demographic characteristics of 241 patients on clozapine were collected through a retrospective chart review. The median (interquartile range, IQR) follow-up from illness onset was 25.0 (IQR = 24.0) years. Clozapine response was assessed at median 10.8 (IQR = 14.0) months (Time 1, T1) and 7.2 (IQR = 13.5) years (Time 2, T2) after its initiation. It was evaluated by chart reviewers based on the information provided in clinical notes. Binomial logistic regression was used to determine clinico-demographic factors associated with clozapine non-response at both T1 and T2 (i.e. stable UTRS, S-UTRS) compared to clozapine response at both times (i.e. stable clozapine responders, S-ClozResp). Among clozapine responders (n = 122) at T1, 83.6% remained clozapine responsive and 16.4% became non-responsive at T2. In the UTRS group (n = 119) at T1, 87.4% remained clozapine non-responsive and 12.6% became responsive at T2. Duration of delay in clozapine initiation (OR = 0.94, Wald χ² = 5.33, p = 0.021) and number of pre-clozapine hospitalizations (OR = 0.95, Wald χ² = 5.20, p = 0.023) were associated with S-UTRS. Most UTRS patients were non-responsive to clozapine from the start of treatment. Preventing delay in initiating clozapine and relapses could help promote long-term clozapine response in patients with treatment-resistant schizophrenia. Future longitudinal studies are required to explore the neuropathological correlates of relapses and delay in clozapine initiation.

Inefficient neural system stabilization: a theory of spontaneous resolutions and recurrent relapses in psychosis

A striking feature of psychosis is its heterogeneity. Presentations of psychosis vary from transient symptoms with no functional consequence in the general population to a tenacious illness at the other extreme, with a wide range of variable trajectories in between. Even among patients with schizophrenia, who are diagnosed on the basis of persistent deterioration, marked variation is seen in response to treatment, frequency of relapses and degree of eventual recovery. Existing theoretical accounts of psychosis focus almost exclusively on how symptoms are initially formed, with much less emphasis on explaining their variable course. In this review, I present an account that links several existing notions of the biology of psychosis with the variant clinical trajectories. My aim is to incorporate perspectives of systems neuroscience in a staging framework to explain the individual variations in illness course that follow the onset of psychosis.

Relapse prediction in schizophrenia through digital phenotyping: a pilot study

Among individuals diagnosed, hospitalized, and treated for schizophrenia, up to 40% of those discharged may relapse within 1 year even with appropriate treatment. Passively collected smartphone behavioral data present a scalable and at present underutilized opportunity to monitor patients in order to identify possible warning signs of relapse. Seventeen patients with schizophrenia in active treatment at a state mental health clinic in Boston used the Beiwe app on their personal smartphone for up to 3 months. By testing for changes in mobility patterns and social behavior over time as measured through smartphone use, we were able to identify statistically significant anomalies in patient behavior in the days prior to relapse. We found that the rate of behavioral anomalies detected in the 2 weeks prior to relapse was 71% higher than the rate of anomalies during other time periods. Our findings show how passive smartphone data, data collected in the background during regular phone use without active input from the subjects, can provide an unprecedented and detailed view into patient behavior outside the clinic. Real-time detection of behavioral anomalies could signal the need for an intervention before an escalation of symptoms and relapse occur, therefore reducing patient suffering and reducing the cost of care.

Guidelines for the Pharmacotherapy of Schizophrenia in Adults

OBJECTIVE

The present guidelines address the pharmacotherapy of schizophrenia in adults across different stages, phases, and symptom domains.

METHOD

Guidelines were developed using the ADAPTE process, which takes advantage of existing guidelines. Six guidelines were identified for adaptation, with recommendations extracted from each. For those specific to the pharmacotherapy of schizophrenia in adults, a working group selected between guidelines and recommendations to create an adapted guideline.

RESULTS

Recommendations can be categorized into 6 areas that include 1) first-episode schizophrenia, 2) acute exacerbation, 3) relapse prevention and maintenance treatment, 4) treatment-resistant schizophrenia, 5) clozapine-resistant schizophrenia, and 6) specific symptom domains. For each category, recommendations are made based on the available evidence, which is discussed and linked to other established guidelines.

CONCLUSIONS

In most cases, evidence-based recommendations are made that can be used to guide current clinical treatment and decision making. Notably, however, there is a paucity of established evidence to guide treatment decision making in the case of clozapine-resistant schizophrenia, a subsample that represents a sizable proportion of those with schizophrenia.

Realising stratified psychiatry using multidimensional signatures and trajectories

Background

Stratified or personalised medicine targets treatments for groups of individuals with a disorder based on individual heterogeneity and shared factors that influence the likelihood of response. Psychiatry has traditionally defined diagnoses by constellations of co-occurring signs and symptoms that are assigned a categorical label (e.g. schizophrenia). Trial methodology in psychiatry has evaluated interventions targeted at these categorical entities, with diagnoses being equated to disorders. Recent insights into both the nosology and neurobiology of psychiatric disorder reveal that traditional categorical diagnoses cannot be equated with disorders. We argue that current quantitative methodology (1) inherits these categorical assumptions, (2) allows only for the discovery of average treatment response, (3) relies on composite outcome measures and (4) sacrifices valuable predictive information for stratified and personalised treatment in psychiatry.

Methods and findings

To achieve a truly ‘stratified psychiatry’ we propose and then operationalise two necessary steps: first, a formal multi-dimensional representation of disorder definition and clinical state, and second, the similar redefinition of outcomes as multidimensional constructs that can expose within- and between-patient differences in response. We use the categorical diagnosis of schizophrenia—conceptualised as a label for heterogeneous disorders—as a means of introducing operational definitions of stratified psychiatry using principles from multivariate analysis. We demonstrate this framework by application to the Clinical Antipsychotic Trials of Intervention Effectiveness dataset, showing heterogeneity in both patient clinical states and their trajectories after treatment that are lost in the traditional categorical approach with composite outcomes. We then systematically review a decade of registered clinical trials for cognitive deficits in schizophrenia highlighting existing assumptions of categorical diagnoses and aggregate outcomes while identifying a small number of trials that could be reanalysed using our proposal.

Conclusion

We describe quantitative methods for the development of a multi-dimensional model of clinical state, disorders and trajectories which practically realises stratified psychiatry. We highlight the potential for recovering existing trial data, the implications for stratified psychiatry in trial design and clinical treatment and finally, describe different kinds of probabilistic reasoning tools necessary to implement stratification.

Antipsychotic Induced Dopamine Supersensitivity Psychosis: A Comprehensive Review

Chronic prescription of antipsychotics seems to lose its therapeutic benefits in the prevention of recurring psychotic symptoms. In many instances, the occurrence of relapse from initial remission is followed by an increase in dose of the prescribed antipsychotic. The current understanding of why this occurs is still in its infancy, but a controversial idea that has regained attention recently is the notion of iatrogenic dopamine supersensitivity. Studies on cell cultures and animal models have shown that long-term antipsychotic use is linked to both an upregulation of dopamine D₂-receptors in the striatum and the emergence of enhanced receptor affinity to endogenous dopamine. These findings have been hypothesized to contribute to the phenomenon known as dopamine supersensitivity psychosis (DSP), which has been clinically typified as the foundation of rebound psychosis, drug tolerance, and tardive dyskinesia. The focus of this review is the update of evidence behind the classification of antipsychotic induced DSP and an investigation of its relationship to treatment resistance. Since antipsychotics are the foundation of illness management, a greater understanding of DSP and its prevention may greatly affect patient outcomes.

Antipsychotic Adherence and Rehospitalization in Schizophrenia Patients Receiving Oral Versus Long-Acting Injectable Antipsychotics Following Hospital Discharge

BACKGROUND

Antipsychotic medications are a central component of effective treatment for schizophrenia, but nonadherence is a significant problem for the majority of patients. Long-acting injectable (LAI) antipsychotic medications are a recommended treatment option for nonadherent patients, but evidence regarding their potential advantages has been mixed. Observational data on newer, second-generation LAI antipsychotic medications have been limited given their more recent regulatory approval and availability.

OBJECTIVE

To examine antipsychotic medication nonadherence, discontinuation, and rehospitalization outcomes in Medicaid patients receiving oral versus LAI antipsychotic medications in the 6 months after a schizophrenia-related hospitalization.

METHODS

The 2010-2013 Truven Health Analytics MarketScan Medicaid research claims database was used to identify adult patients with a recent history of nonadherence (prior 6 months) who received an oral or LAI antipsychotic medication within 30 days after an index schizophrenia-related hospitalization. Primary outcome measures were nonadherence (proportion of days covered less than  0.80), discontinuation (continuous medication gap ≥ 60 days), and schizophrenia-related rehospitalization, all in the 6 months after discharge. Descriptive analyses compared users of oral versus LAI antipsychotic medication on sociodemographic, clinical, and treatment characteristics. Logistic regressions were used to examine associations between use of oral versus LAI antipsychotics and each study outcome while controlling for observed differences in sample characteristics. All outcomes were compared at 3 levels of analysis: overall LAI class, LAI antipsychotic generation (first-generation [FGA] or second-generation [SGA] antipsychotics), and individual LAI agent (fluphenazine decanoate, haloperidol decanoate, risperidone LAI, and paliperidone palmitate).

RESULTS

Of the final sample, 91% (n = 3,428) received oral antipsychotics, and 9.0% (n = 340) received LAI antipsychotics after discharge. Slightly over half (n =183, 53.8%) of LAI users used an SGA LAI. A smaller percentage of patients receiving LAIs were nonadherent (51.8% vs. 67.7%, P  less than  0.001); had a 60-day continuous gap in medication (23.8% vs. 39.4%, P  less than  0.001); and were rehospitalized for schizophrenia (19.1% vs. 25.3%, P = 0.01) compared with patients receiving oral medications. The size of these differences was magnified when comparing SGA LAI users with users of oral antipsychotics for nonadherence. After controlling for all differences in measured covariates, LAI initiators had lower odds of being nonadherent (adjusted odds ratio [AOR] = 0.35, 95% CI = 0.27-0.46, P  less than  0.001) and of having continuous 60-day gaps (AOR = 0.45, 95% CI = 0.34-0.60, P  less than  0.001) when compared with patients receiving oral medications. Both FGA and SGA LAI users had lower odds of nonadherence compared with patients receiving oral antipsychotics. Similarly, FGA LAI users (AOR = 0.58, 95% CI = 0.40-0.85, P = 0.005) and SGA LAI initiators (AOR = 0.34, 95% CI =0.23-0.51, P  less than  0.001) had lower odds of a 60-day continuous gap compared with patients receiving oral antipsychotics. Compared with those receiving oral antipsychotics, LAI initiators also had lower odds of rehospitalization (AOR = 0.73, 95% CI = 0.54-0.99, P = 0.041); however, when examined separately, only patients receiving SGA LAIs (AOR = 0.59, 95% CI = 0.38-0.90, P = 0.015) and not FGA LAIs (AOR = 0.90, 95% CI = 0.60-1.34, P = 0.599) had a statistically significant reduction in odds of rehospitalization. Among individual LAIs, odds of rehospitalization only among initiators of paliperidone palmitate were statistically different from those among users of oral antipsychotics (AOR = 0.53, 95% CI = 0.30-0.94, P = 0.031). While odds of rehospitalization were 33% lower among patients receiving risperidone LAI compared with those receiving oral antipsychotics, the estimate did not reach statistical significance (AOR = 0.67, 95% CI = 0.37-1.22, P = 0.194). 

CONCLUSIONS

This claims-based analysis of posthospitalization adherence and rehospitalization outcomes in Medicaid patients with schizophrenia adds to the growing real-world evidence base of the benefits of LAI antipsychotic medications in routine clinical practice, particularly with regard to second-generation LAIs. As new SGA formulations become available for long-acting use, real-world studies with larger sample sizes will be needed to further delineate their potential advantages in terms of clinical outcomes and costs.

Clinical predictors of therapeutic response to antipsychotics in schizophrenia

The search for clinical outcome predictors for schizophrenia is as old as the field of psychiatry. However, despite a wealth of large, longitudinal studies into prognostic factors, only very few clinically useful outcome predictors have been identified. The goal of future treatment is to either affect modifiable risk factors, or use nonmodifiable factors to parse patients into therapeutically meaningful subgroups. Most clinical outcome predictors are nonspecific and/or nonmodifiable. Nonmodifiable predictors for poor odds of remission include male sex, younger age at disease onset, poor premorbid adjustment, and severe baseline psychopathology. Modifiable risk factors for poor therapeutic outcomes that clinicians can act upon include longer duration of untreated illness, nonadherence to antipsychotics, comorbidities (especially substance-use disorders), lack of early antipsychotic response, and lack of improvement with non-clozapine antipsychotics, predicting clozapine response. It is hoped that this limited capacity for prediction will improve as pathophysiological understanding increases and/or new treatments for specific aspects of schizophrenia become available.

The safety, efficacy and tolerability of Abilify Maintena for the treatment of schizophrenia

Relapse in schizophrenia has been associated with poor adherence to oral medication. A possible method to optimize medication adherence could be to switch patients from oral to depot medication. In this respect, aripiprazole long acting injectable (ALAI) significantly delayed time to impending relapse when compared with placebo (p < 0.0001), while ALAI was generally well tolerated during both short-term and long-term studies. A literature search, using PubMed was conducted to identify relevant publications. Available evidence suggests that ALAI may be a viable treatment option for patients with schizophrenia, but before it can be concluded whether or not all schizophrenia patients could benefit from a switch to depot formulations, several questions remain to be answered. Thus, there is a great need for randomized controlled trials comparing depot medications with their oral equivalents.

The Use of Continuous Treatment Versus Placebo or Intermittent Treatment Strategies in Stabilized Patients with Schizophrenia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials with First- and Second-Generation Antipsychotics

BACKGROUND

Although continuous treatment with antipsychotics is still recommended as the gold standard treatment paradigm for all patients with schizophrenia, some clinicians question whether continuous antipsychotic treatment is necessary, or even justified, for every patient with schizophrenia who has been stabilized on antipsychotics.

OBJECTIVE

The primary objectives of this systematic review and meta-analysis were (i) to compare relapse/hospitalization risks of stabilized patients with schizophrenia under active versus intermittent or placebo treatment conditions; (ii) to examine the role of several study characteristics, possibly intervening in the relationship between relapse risk and treatment condition; and (iii) to examine whether time to relapse is associated with antipsychotic treatment duration.

METHODS

A systematic literature search, using the MEDLINE database (1950 until November 2014), was conducted for English-language published randomized controlled trials, covering a follow-up time period of at least 6 months, and investigating relapse/rehospitalization and/or time-to-relapse rates with placebo or intermittent treatment strategies versus continuous treatment with oral and long-acting injectable first- or second-generation antipsychotics (FGAs/SGAs) in stabilized patients with schizophrenia. Additional studies were identified through searches of reference lists of other identified systematic reviews and Cochrane reports. Two meta-analyses (placebo versus continuous and intermittent versus continuous treatment) were performed to obtain an optimal estimation of the relapse/hospitalization risks of stabilized patients with schizophrenia under these treatment conditions and to assess the role of study characteristics. For time-to-relapse data, a descriptive analysis was performed.

RESULTS

Forty-eight reports were selected as potentially eligible for our meta-analysis. Of these, 21 met the inclusion criteria. Twenty-five records, identified through Cochrane and other systematic reviews and fulfilling the inclusion criteria, were added, resulting in a total of 46 records. Stabilized patients with schizophrenia who have been exposed for at least 6 months to intermittent or placebo strategies, respectively, have a 3 (odds ratio [OR] 3.36; 95% CI 2.36-5.45; p < 0.0001) to 6 (OR 5.64; 95% CI 4.47-7.11; p < 0.0001) times increased risk of relapse, compared with patients on continuous treatment. The availability of rescue medication (p = 0.0102) was the only study characteristic explaining systematic differences in the OR for relapse between placebo versus continuous treatment across studies. Studies reporting time-to-relapse data show that the time to (impending) relapse is always significantly delayed with continuous treatment, compared with placebo or intermittent treatment strategies. Although the interval between treatment discontinuation and symptom recurrence can be highly variable, mean time-to-relapse data seem to indicate a failure of clinical stability before 7-14 months with intermittent and before 5 months with placebo treatment strategies. For all reports included in this systematic review, median time-to-relapse rates in the continuous treatment group were not estimable as <50% of the patients in this treatment condition relapsed before the end of the study.

CONCLUSIONS

With continuous treatment, patients have a lower risk of relapse and remain relapse free for a longer period of time compared with placebo and intermittent treatment strategies. Moreover, 'success rates' in the intermittent treatment conditions are expected to be an overestimate of actual outcome rates. Therefore, continuous treatment remains the 'gold standard' for good clinical practice, particularly as, until now, only a few and rather general valid predictors for relapse in schizophrenia are known and subsequent relapses may contribute to functional deterioration as well as treatment resistance in patients with schizophrenia.