Negative symptoms of schizophrenia: new developments and unanswered research questions

Prodopaminergic Drugs for Treating the Negative Symptoms of Schizophrenia: Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

The negative symptoms of schizophrenia pose a heavy burden on patients and relatives and represent an unmet therapeutic need. The observed association of negative symptoms with impaired reward system function has stimulated research on prodopaminergic agents as potential adjunctive treatments.

METHODS

We conducted a systematic review and meta-analysis of published randomized controlled trials of amphetamine, methylphenidate, modafinil, armodafinil, lisdexamphetamine, L-dopa, levodopa, bromocriptine, cabergoline, quinagolide, lisuride, pergolide, apomorphine, ropinirole, pramipexole, piribedil, and rotigotine augmentation in schizophrenia and schizoaffective disorder.Medline, EMBASE, and several other databases as well as trial registries were searched for placebo-controlled trials.

RESULTS

Ten randomized controlled trials were included in the meta-analysis, 6 trials on modafinil, 2 on armodafinil, 1 on L-dopa, and 1 on pramipexole. Overall, prodopaminergic agents did not significantly reduce negative symptoms. Restricting the analysis to studies requiring a minimum threshold for negative symptom severity, modafinil/armodafinil showed a significant but small effect on negative symptoms. A subset of studies allowed for calculating specific effects for the negative symptom dimensions diminished expression and amotivation, but no significant effect was found. Prodopaminergic agents did not increase positive symptom scores.

CONCLUSIONS

The currently available evidence does not allow for formulating recommendations for the use of prodopaminergic agents for the treatment of negative symptoms. Nevertheless, the observed improvement in studies defining a minimum threshold for negative symptom severity in the absence of an increase in positive symptoms clearly supports further research on these agents.

Shared and dissociable features of apathy and reward system dysfunction in bipolar I disorder and schizophrenia

BACKGROUND

Bipolar disorder I (BD-I) is defined by episodes of mania, depression and euthymic states. These episodes are among other symptoms characterized by altered reward processing and negative symptoms (NS), in particular apathy. However, the neural correlates of these deficits are not well understood.

METHODS

We first assessed the severity of NS in 25 euthymic BD-I patients compared with 25 healthy controls (HC) and 27 patients with schizophrenia (SZ). Then, we investigated ventral (VS) and dorsal striatal (DS) activation during reward anticipation in a Monetary Incentive Delayed Task and its association with NS.

RESULTS

In BD-I patients NS were clearly present and the severity of apathy was comparable to SZ patients. Apathy scores in the BD-I group but not in the SZ group correlated with sub-syndromal depression scores. At the neural level, we found significant VS and DS activation in BD-I patients and no group differences with HC or SZ patients. In contrast to patients with SZ, apathy did not correlate with striatal activation during reward anticipation. Explorative whole-brain analyses revealed reduced extra-striatal activation in BD-I patients compared with HC and an association between reduced activation of the inferior frontal gyrus and apathy.

CONCLUSION

This study found that in BD-I patients apathy is present to an extent comparable to SZ, but is more strongly related to sub-syndromal depressive symptoms. The findings support the view of different pathophysiological mechanisms underlying apathy in the two disorders and suggest that extra-striatal dysfunction may contribute to impaired reward processing and apathy in BD-I.

Schizophrenia and "unmet needs": From diagnosis to care in Italy

Background.

Schizophrenia is a leading cause of disability. People living with schizophrenia (PLWS) present unemployment, social isolation, excess mortality and morbidity, and poor quality of life. Early recognition and appropriate treatment reduce the risk of chronicity and comorbidity. Personalization and integration of pharmacological and psychosocial interventions, as well as accurate identification and management of psychiatric and somatic comorbidities, can significantly improve mental and physical health of PLWS, promoting recovery.

Methods.

A three-step Delphi approach was used to explore consensus on the essential components of early recognition and intervention, personalization, and integration of care to improve schizophrenia outcome, and on barriers and challenges to close treatment gaps. The consensus involved 8 Italian experts of schizophrenia, 100 psychiatrists from academic and nonacademic settings, including representatives of Italian Society of Psychiatry, and 65 trainees in psychiatry.

Results.

A strong consensus (from mostly agree to totally agree) emerged on the importance of early diagnosis (97%), standardized assessments (91%), correct management of somatic and psychiatric comorbidities (99%), and personalization and integration of care (94%). Lack of time, human resources, and training were identified as the main barriers and challenges to the translation of knowledge into clinical practice.

Conclusions.

The results of this Delphi study demonstrated a strong consensus on main components of schizophrenia care, as well as on unmet needs to promote best practice and gaps between knowledge and clinical practice. The involvement of a large group of professionals and trainees in this in-depth consensus process might contribute to raise awareness and stimulate innovative strategies to improve the outcome of PLWS.

Schizophrenia-An Overview

IMPORTANCE

Schizophrenia is a common, severe mental illness that most clinicians will encounter regularly during their practice. This report provides an overview of the clinical characteristics, epidemiology, genetics, neuroscience, and psychopharmacology of schizophrenia to provide a basis to understand the disorder and its treatment. This educational review is integrated with a clinical case to highlight how recent research findings can inform clinical understanding.

OBSERVATIONS

The first theme considered is the role of early-life environmental and genetic risk factors in altering neurodevelopmental trajectories to predispose an individual to the disorder and leading to the development of prodromal symptoms. The second theme is the role of cortical excitatory-inhibitory imbalance in the development of the cognitive and negative symptoms of the disorder. The third theme considers the role of psychosocial stressors, psychological factors, and subcortical dopamine dysfunction in the onset of the positive symptoms of the disorder. The final theme considers the mechanisms underlying treatment for schizophrenia and common adverse effects of treatment.

CONCLUSIONS AND RELEVANCE

Schizophrenia has a complex presentation with a multifactorial cause. Nevertheless, advances in neuroscience have identified roles for key circuits, particularly involving frontal, temporal, and mesostriatal brain regions, in the development of positive, negative, and cognitive symptoms. Current pharmacological treatments operate using the same mechanism, blockade of dopamine D2 receptor, which contribute to their adverse effects. However, the circuit mechanisms discussed herein identify novel potential treatment targets that may be of particular benefit in symptom domains not well served by existing medications.

Negative symptom severity at discharge from an index hospitalization and subsequent use of psychiatric care resources: A retrospective 1-year follow-up study on 450 patients with schizophrenia spectrum disorders

Negative symptoms of schizophrenia have a great impact on patients' functioning and are among the most important contributors to subject's disability. However, few studies have assessed the role of type and severity of symptomatology of schizophrenia on the psychiatric care resource utilization. We investigated if the clinical profile of patients at discharge from an index hospitalization might be associated with a different use of psychiatric care resources in the subsequent 1-year period in a large population of patients with schizophrenia spectrum disorders. Clinical records of 450 patients with schizophrenia spectrum disorders admitted in an acute psychiatric inpatient service and subsequently followed in the outpatient services of the same Department were reviewed. Patients with more severe negative symptoms at discharge from hospital showed a higher number and duration of hospitalizations in the 1-year follow-up, as well as a higher number of rehabilitative residential admissions than patients with milder severity of negative symptoms. The same was true for patients with predominant negative symptoms. A global resource utilization index indicated a higher use of psychiatric resources in patients with higher severity of negative symptoms. In conclusion, showing moderate to severe negative symptoms versus positive symptoms at discharge from a hospitalization for an acute exacerbation of schizophrenia spectrum disorder does predict a higher use of psychiatric care resources. This underlines the importance of relieving negative symptoms even in the acute phase of treatment and the need to develop more effective treatments for this symptom dimension.

Polypharmacy in schizophrenia

Schizophrenia is a severe mental disorder characterized by a heterogeneous symptom profile which comprises a clinical platform for widespread use of polypharmacy even though antipsychotic monotherapy is the recommended treatment regimen. This narrative review provides a summary of the current gap between evidence and practice for use of antipsychotic combination therapy in patients with schizophrenia. Antipsychotic polypharmacy is frequently prescribed instead of following international consensus of clozapine monotherapy in treatment-resistant patients. Antipsychotic-benzodiazepine combination therapy clearly has a role in the treatment of acute agitation whereas there is no evidence to support an effect on core schizophrenia symptoms when chronically prescribed. Antidepressants are typically added to antipsychotic treatment in case of persistent negative symptoms. Available evidence suggests that antidepressants may improve negative symptom control in schizophrenia. Combining an antipsychotic with an antiepileptic is not supported by any firm evidence, but individual mood stabilizers have come out positively in single trials. Generally, the evidence base for polypharmacy in schizophrenia maintenance treatment is sparse but may be warranted in certain clinical situations. Therapeutic benefits and side effects should be carefully monitored and considered to ensure a beneficial risk-benefit ratio if prescribing polypharmacy for specific clinical indications.

Examining bi-anodal transcranial direct current stimulation (tDCS) over bilateral dorsolateral prefrontal cortex coupled with bilateral extracephalic references as a treatment for negative symptoms in non-acute schizophrenia patients: A randomized, double-blind, sham-controlled trial

No studies have examined the efficacy of bi-anodal transcranial direct current stimulation (tDCS) over bilateral dorsolateral prefrontal cortex (DLPFC) coupled with bilateral extracephalic references in treating negative symptoms of non-acute schizophrenia patients. This study aimed to investigate the therapeutic effects of the new approach of tDCS on negative symptoms, other schizophrenia symptoms, cognitive deficits and psychosocial functioning in a double-blind, randomized, sham-controlled trial. Patients with non-acute schizophrenia (N = 60) in randomized order received sham treatment or bilaterally provided tDCS (2 mA, twice-daily sessions for five consecutive days) with the anode over the DLPFC and the reference (cathode) over the ipsilateral forearm. The negative symptoms as measured by a dimensional approach of Positive and Negative Syndrome Scale (PANSS) were rapidly reduced by bimodal tDCS relative to sham stimulation (F = 24.86, Cohen's d = 0.661, p = 6.11 × 10^-6). The beneficial effect on negative symptoms lasted for up to 3 months. The authors also observed improvement with tDCS of psychosocial functioning as measured by the global score of Personal and Social Performance scale (PSP) and psychopathological symptoms especially for disorganization and cognitive symptoms as measured by the PANSS. No effects were observed on other schizophrenia symptom dimensions and the performance on a series of neurocognitive tests. Our results show promise for bi-anodal tDCS over bilateral DLPFC using bilateral extracephalic references in treating negative symptoms and other selected manifestations of schizophrenia. Further studies with electrophysiological or imaging evaluation help unravel the exact mechanism of action of this novel stimulation parameter of tDCS in schizophrenia patients. (ClinicalTrials.gov ID:NCT03701100).

Inflammation and Negative Symptoms of Schizophrenia: Implications for Reward Processing and Motivational Deficits

Negative symptoms of schizophrenia are debilitating and chronic in nature, are difficult to treat, and contribute to poor functional outcomes. Motivational deficits are a core negative symptom and may involve alterations in reward processing, which involve subcortical regions such as the basal ganglia. More specifically, dopamine-rich regions like the ventral striatum, have been implicated in these reward-processing deficits. Inflammation is one mechanism that may underlie negative symptoms, and specifically motivational deficits, via the effects of inflammatory cytokines on the basal ganglia. Previous work has demonstrated that inflammatory stimuli decrease neural activity in the ventral striatum and decrease connectivity in reward-relevant neural circuitry. The immune system has been shown to be involved in the pathophysiology of schizophrenia, and inflammatory cytokines have been shown to be altered in patients with the disorder. This paper reviews the literature on associations between inflammatory markers and negative symptoms of schizophrenia as well as the role of anti-inflammatory drugs to target negative symptoms. We also review the literature on the role of inflammation and reward processing deficits in both healthy controls and individuals with depression. We use the literature on inflammation and depression as a basis for a model that explores potential mechanisms responsible for inflammation modulating certain aspects of negative symptoms in patients with schizophrenia. This approach may offer novel targets to treat these symptoms of the disorder that are significant barriers to functional recovery and do not respond well to available antipsychotic medications.

Improvement of Negative Symptoms in Schizophrenia with Paliperidone Palmitate 1-Month and 3-Month Long-Acting Injectables: Results from a Phase 3 Non-Inferiority Study

BACKGROUND

Negative symptoms in schizophrenia are associated with impairments in social and cognitive functioning leading to substantial long-term disability. Available antipsychotic treatments have demonstrated only modest benefit in the improvement of negative symptoms.

OBJECTIVE

To compare improvements in negative symptoms among patients treated with paliperidone palmitate 3-month (PP3M) or paliperidone palmitate 1-month (PP1M) long-acting injectable (LAI) formulations.

METHODS

Data from a randomized double-blind (DB), phase-3, non-inferiority study in patients with schizophrenia were analyzed. Following screening, patients entered a 17-week open-label (OL) phase to receive flexibly dosed PP1M followed by a 48-week DB phase where patients were randomized (1:1) to receive either PP1M or PP3M. Positive and Negative Syndrome Scale (PANSS) total scores with emphasis on 7-item negative subscale scores for PP1M vs PP3M were assessed.

RESULTS

Of 1429 patients enrolled, 1016 were randomized to receive PP3M (n=504) or PP1M (n=512). At baseline, mean (SD) PANSS negative subscale was 23.2 (4.60) and negative symptom factor score was 22.3 (4.87), indicating moderate-to-severe negative symptoms. Negative subscale and symptoms factor scores showed continuous improvements throughout OL (15.9 [4.99]) and DB (14.9 [4.81]) phases. Mean (SD) changes from DB baseline in the PANSS negative subscale score were comparable between PP1M (-1.4 [3.67]) and PP3M (-1.4 [3.63]) treatment groups.

CONCLUSION

Treatment with PP3M or PP1M demonstrated comparable improvement in negative symptoms in patients with moderate-to-severe negative symptoms and in patients with prominent negative symptoms. Long-term treatment with PP3M demonstrated benefit, suggesting that continuous antipsychotic medication treatment for >1 year is needed to achieve greater benefit for negative symptoms.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01515423.

Evidence-based guidelines for the pharmacological treatment of schizophrenia: Updated recommendations from the British Association for Psychopharmacology

These updated guidelines from the British Association for Psychopharmacology replace the original version published in 2011. They address the scope and targets of pharmacological treatment for schizophrenia. A consensus meeting was held in 2017, involving experts in schizophrenia and its treatment. They were asked to review key areas and consider the strength of the evidence on the risk-benefit balance of pharmacological interventions and the clinical implications, with an emphasis on meta-analyses, systematic reviews and randomised controlled trials where available, plus updates on current clinical practice. The guidelines cover the pharmacological management and treatment of schizophrenia across the various stages of the illness, including first-episode, relapse prevention, and illness that has proved refractory to standard treatment. It is hoped that the practice recommendations presented will support clinical decision making for practitioners, serve as a source of information for patients and carers, and inform quality improvement.

Negative Symptoms and Functioning in Youth at Risk of Psychosis: A Systematic Review and Meta-analysis

LEARNING OBJECTIVE

After participating in this activity, learners should be better able to:• Evaluate the relationship between negative symptoms and functioning in youth at clinical high risk for psychosis.

AIM

Youth at CHR for psychosis often demonstrate significant negative symptoms and poor functioning, though the magnitude and direction of the relationship between the two remains unknown. The objective of this systematic review is to summarize the relationship between negative symptoms and functioning in CHR samples.

METHOD

Electronic databases CINAHL, EBM, Embase, MEDLINE, and PsycINFO were searched from inception. Studies were selected if they included any study that reported a relationship between negative symptoms and functioning in youth at clinical high risk (CHR). The correlation coefficient r was converted to Cohen's d, and all random-effects meta-analyses were performed using the transformed values.

RESULTS

Forty-one studies met the inclusion criteria, including a total of 4574 individuals at CHR for psychosis. Negative symptom total scores were significantly associated with poorer global functioning (d, -1.40; 95% CI, -1.82 to -0.98; I = 79.4%; p < .001 [9 studies, n = 782]), social functioning (d, -1.10; 95% CI, -1.27 to -0.93; I = 10.40%; p < .001 [12 studies, n = 811]), and role functioning (d, -0.96; 95% CI, -1.17 to -0.76; I = 41.1%; p < .001 [9 studies, n = 881]). In addition, negative symptoms were consistently associated with poor premorbid functioning. When examining negative symptom domains, avolition, anhedonia, and blunted affect were each significantly and independently associated with poorer social functioning and role functioning. In terms of prediction models, negative symptoms contributed to the prediction of lower functioning across multiple studies.

CONCLUSION

This meta-analysis demonstrates a strong relationship between negative symptoms and functioning in youth at clinical high risk for psychosis.

Negative Symptoms in Schizophrenia: A Review and Clinical Guide for Recognition, Assessment, and Treatment

Schizophrenia is frequently a chronic and disabling disorder, characterized by heterogeneous positive and negative symptom constellations. The objective of this review was to provide information that may be useful for clinicians treating patients with negative symptoms of schizophrenia. Negative symptoms are a core component of schizophrenia that account for a large part of the long-term disability and poor functional outcomes in patients with the disorder. The term negative symptoms describes a lessening or absence of normal behaviors and functions related to motivation and interest, or verbal/emotional expression. The negative symptom domain consists of five key constructs: blunted affect, alogia (reduction in quantity of words spoken), avolition (reduced goal-directed activity due to decreased motivation), asociality, and anhedonia (reduced experience of pleasure). Negative symptoms are common in schizophrenia; up to 60% of patients may have prominent clinically relevant negative symptoms that require treatment. Negative symptoms can occur at any point in the course of illness, although they are reported as the most common first symptom of schizophrenia. Negative symptoms can be primary symptoms, which are intrinsic to the underlying pathophysiology of schizophrenia, or secondary symptoms that are related to psychiatric or medical comorbidities, adverse effects of treatment, or environmental factors. While secondary negative symptoms can improve as a consequence of treatment to improve symptoms in other domains (ie, positive symptoms, depressive symptoms or extrapyramidal symptoms), primary negative symptoms generally do not respond well to currently available antipsychotic treatment with dopamine D₂ antagonists or partial D₂ agonists. Since some patients may lack insight about the presence of negative symptoms, these are generally not the reason that patients seek clinical care, and clinicians should be especially vigilant for their presence. Negative symptoms clearly constitute an unmet medical need in schizophrenia, and new and effective treatments are urgently needed.

Effectiveness of Cerebellar Circuitry Modulation in Schizophrenia: A Systematic Review

Structural and functional abnormalities of the cerebellum have been observed in schizophrenia since the first neuroimaging studies. More recently, the functions of the cerebellum have been extended beyond sensorimotor control to include participation in higher-level cognition and affective regulation. Consistently, the "cognitive dysmetria" theory posits that dysfunctions of cortical-subcortical-cerebellar circuitry may be crucial for the pathogenesis of different clinical features of schizophrenia. This conceptual framework offers a set of testable hypotheses, now that various tools to exert direct modulation of cerebellar activity are available. We conducted a systematic review of studies examining the effects of cerebellar modulation in schizophrenia. Two independent authors conducted a search within PubMed for articles published up to April 2019 and identified 10 studies (three randomized controlled trials, two open-label studies, two case reports, one preclinical study) describing the effects of cerebellar circuitry modulation in patients with schizophrenia or animal models. The majority of interventions were uncontrolled and used stimulation of the cerebellar vermis, using transcranial magnetic stimulation or transcranial direct-current stimulation. Most studies detected improvements after cerebellar modulation. Clinical changes mostly pertained the domains of negative symptoms, depressive symptoms and cognitive functions. In conclusion, few studies examined the effects of cerebellar modulation in schizophrenia but yielded promising results. This approach may hold therapeutic potential, pending further methodologically robust replication.

Spanish validation of the self-evaluation of negative symptoms scale SNS in an adolescent population

BACKGROUND

Negative symptoms (NS) may be observed in the general population in an attenuated form and in high-risk mental states. However, they have been less studied in the general population than positive symptoms, in spite of their importance at the insidious onset of schizophrenia and their appearance before positive symptoms. This study aimed to analyze the empirical structure of the Spanish version of the Self-Evaluation of Negative Symptoms (SNS) Scale and find its psychometric properties and invariance of measurement across sex and age in a sample of adolescents.

METHODS

The sample consisted of 4521 adolescents (53.6% female) from 11 to 18 years of age.

RESULTS

Confirmatory Factor Analysis of the SNS confirmed an internal structure of five first-order factors by the characteristic dimensions of NS: avolition, social withdrawal, diminished emotional range, anhedonia, alogia, and one second-order factor which includes the total NS score. Multi-group confirmatory factor analysis showed that the scale was invariant across sex and age. Total scale reliability was adequate. A strong relationship was found between the SNS with depressive symptomatology, moderate with ideas of reference and low with aberrant salience.

CONCLUSION

The results back use of the Spanish version of the SNS scale for detection of NS in the general population of adolescents.

Reduced mu opioid receptor availability in schizophrenia revealed with [11C]-carfentanil positron emission tomographic Imaging

Negative symptoms, such as amotivation and anhedonia, are a major cause of functional impairment in schizophrenia. There are currently no licensed treatments for negative symptoms, highlighting the need to understand the molecular mechanisms underlying them. Mu-opioid receptors (MOR) in the striatum play a key role in hedonic processing and reward function and are reduced post-mortem in schizophrenia. However, it is unknown if mu-opioid receptor availability is altered in-vivo or related to negative symptoms in schizophrenia. Using [11 C]-carfentanil positron emission tomography (PET) scans in 19 schizophrenia patients and 20 age-matched healthy controls, here we show a significantly lower MOR availability in patients with schizophrenia in the striatum (Cohen's d = 0.7), and the hedonic network. In addition, we report a marked global increase in inter-regional covariance of MOR availability in schizophrenia, largely due to increased cortical-subcortical covariance.

Baseline psychopathology and relationship to longitudinal functional outcome in attenuated and early first episode psychosis

BACKGROUND

As efforts intensify to intervene early among those at risk for psychosis, examination of the relationship between presenting psychopathology and long-term functional outcome may guide treatment decision-making and offer a means to prevent or reduce chronic disability.

METHODS

Data were collected through the Early Detection and Intervention for the Prevention of Psychosis Program (EDIPPP), a multisite national trial testing the efficacy of an early intervention for youth at risk of developing psychosis. Participants were followed prospectively and completed comprehensive evaluations at 6, 12, and 24 months, including the Structured Interview for Prodromal Syndromes (SIPS) and the Global Social and Role Functioning Scales. The present analyses included 327 participants and examined the relationships between baseline symptoms and longitudinal global social and role functioning using a linear mixed modeling approach.

RESULTS

Higher baseline negative symptoms and deteriorated thought process predicted worse social and role functioning in the follow-up period. The effect of negative symptoms on social functioning, however, was moderated by positive symptoms, and the relationship between positive symptoms and social functioning changed over time. Baseline positive symptoms, distress, and level of symptom severity were not predictors of either social or role functioning.

CONCLUSIONS

Baseline negative symptoms and thought disorder appear to predict functional outcome for up to two years among adolescents and young adults at risk for psychosis. Developing effective interventions to target these symptoms may be critical to promote functional recovery among those experiencing attenuated symptoms or a first episode of psychosis.

A large European, multicenter, multinational validation study of the Brief Negative Symptom Scale

Negative symptoms represent an unmet need of treatment in schizophrenia. Although a consensus exists on negative symptom construct, and second generation assessment instruments reflecting the consensus are available, studies still rely upon old assessment instruments, that do not reflect recent conceptualizations and might limit progress in the search for effective treatments. This is often the case in the European context, where one of the challenges encountered in designing large studies is the availability of validated instruments in the many languages of the continent. To address this challenge and promote sound research on negative symptoms in Europe, the ECNP Schizophrenia Network coordinated a large multicenter, multinational validation study of the Brief Negative Symptom Scale (BNSS). Clinically-stable subjects with schizophrenia (SCZ, N = 249) were recruited from 10 European Countries. Apart from BNSS, subjects were administered the Positive and Negative Syndrome Scale (PANSS) and standardized instruments for depression, extrapyramidal symptoms and psychosocial functioning. Results showed an excellent internal consistency, convergent and discriminant validity of BNSS and replicated a 5 factor-model. A larger number of subjects with predominant negative symptoms, i.e. the target population for clinical trials, was identified by using the BNSS compared to the PANSS. Regression analysis showed that BNSS-avolition, a key negative symptom poorly assessed by PANSS, explained 23.9% of psychosocial functioning, while no combination of the PANSS core negative symptoms showed the same impact on functioning. The study demonstrated that BNSS has substantial advantages with respect to PANSS for the identification of the avolition domain and subjects with predominant negative symptoms.

Impact of long-term institutionalization on experiential pleasure and motivation in patients with schizophrenia

Anhedonia and amotivation, the hallmarks of negative symptoms in schizophrenia, are believed to be due to "emotion-behavior decoupling," a failure in translating pleasure experience into appropriate goal-directed behavior. A number of studies have reported that long-term institutionalized schizophrenia patients suffer from more severe negative symptoms than community-dwelling patients, but few studies have investigated pleasure experience and motivational behavior in schizophrenia patients who have experienced long-term institutionalization. In this study, we recruited 26 long-term institutionalized schizophrenia patients, 27 community-dwelling schizophrenia patients, and 27 healthy controls. Participants were administered two specific computer-based tasks to assess anhedonia and amotivation. The Anticipatory and Consummatory Pleasure (ACP) Task was used to measure emotion-behavior decoupling and the Effort-Expenditure for Rewards Task (EEfRT) was used to measure amotivation related to rewards. Findings from the ACP Task showed that compared with healthy controls, the coupling between emotion experience and motivated behavior was significantly weaker in both clinical groups, suggesting that emotion-behavior decoupling could be a stable trait in schizophrenia patients. In the EEfRT, compared with both community-dwelling patients and healthy controls, institutionalized patients with schizophrenia failed to expend more effort to gain potential rewards even when reward probability increased. These findings further reveal the underlying mechanism of anhedonia and amotivation and their potential relationships with long-term institutionalization in patients with schizophrenia.

Structure and neural mechanisms of catatonia

Catatonia is a psychomotor syndrome associated with several psychiatric and medical conditions. Psychomotor signs range from stupor to agitation, and include pathognomonic features such as verbigeration and waxy flexibility. Disturbances of volition led to the classification of catatonia as a subtype of schizophrenia, but changes in nosology now recognise the high prevalence in mood disorders, overlap with delirium, and comorbidity with medical conditions. Initial psychometric studies have revealed three behavioural factors, but the structure of catatonia is still unknown. Evidence from brain imaging studies of patients with psychotic disorders indicates increased neural activity in premotor areas in patients with hypokinetic catatonia. However, whether this localised hyperactivity is due to corticocortical inhibition or excess activity of inhibitory corticobasal ganglia loops is unclear. Current treatment of catatonia relies on benzodiazepines and electroconvulsive therapy-both effective, yet unspecific in their modes of action. Longitudinal research and treatment studies, with neuroimaging and brain stimulation techniques, are needed to advance our understanding of catatonia.

Recycling N-acetylcysteine: A review of evidence for adjunctive therapy in schizophrenia

Introduction

All symptoms in schizophrenia may impact functioning. Although Food and Drug Administration-approved medications typically benefit positive symptoms, negative symptoms are generally refractory to medication interventions. N-acetylcysteine's (NAC) influence on glutamatergic neurotransmission has been established. An emerging body of research has attempted to correlate this action with reduction in symptom severity, evaluating response in positive, negative, and cognitive symptom domains.

Methods

A literature review was performed to analyze available data on NAC intervention and improvement in the positive, negative, and cognitive symptom domains in patients with schizophrenia. Quality of evidence was systematically assessed to determine level of certainty in results.

Results

Three randomized controlled trials were identified. Across studies, negative symptoms decreased more with NAC compared to placebo; ranging between 11.9% and 24.1%. The assessment determined a low level of certainty regarding benefit of NAC on negative and cognitive symptoms and moderate certainty for NAC regarding findings of side effects and lack of benefit on positive symptoms.

Discussion

Consistent reporting of benefit in negative symptoms is found across studies of NAC intervention. These improvements are notable for symptoms that have generally remained refractory to medication intervention. Inconsistent benefit was reported in positive and cognitive symptoms. GRADE (grading of recommendations assessment, development and evaluation) assessment of current evidence indicates a low certainty of benefit for negative symptoms with standard use of NAC in patients with schizophrenia. However, a trial of this low-risk intervention may be warranted in patients with resistant negative symptoms and subsequent impaired functioning despite appropriate antipsychotic therapy as they may experience additional benefit in this symptom domain.

Music Therapy as Treatment of Negative Symptoms for Adult Patients Diagnosed with Schizophrenia-Study Protocol for a Randomized, Controlled and Blinded Study

Background: Three Cochrane reviews show that music therapy has a positive effect on schizophrenia concerning general functioning and positive/negative symptoms. This study aims to replicate these results in the Danish health system, a requirement for recommendation in guidelines from the Danish National Board of Health. Methods: The study is a randomized, controlled multi-site study, with a blinded design, aiming to include 90 participants who are 18⁻65 years in age, diagnosed according to ICD-10 with a schizophrenia diagnosis. The participants are randomized to one of two different music therapy activities for 25 weekly sessions. The study interventions are added to standard care. Outcome measures are rated at baseline, after 15 sessions and post therapy. A qualitative interview is performed as a one month follow up at the end of study. The primary intended outcome is a reduction in negative symptoms. The secondary intended outcome is progression in quality of life, alliance and psychosocial functioning. Results: As this study is still running, the results are not yet available. Conclusion: The study will investigate the direct effects of music therapy on negative symptoms as part of schizophrenia in a blinded, randomized trial. If proven effective, music therapy can be added to the small treatment armamentarium of effective therapies for negative symptoms in patients with schizophrenia.

Evoked Potentials Investigations of Deficit Versus Nondeficit Schizophrenia: EEG-MEG Preliminary Data

Heterogeneity of schizophrenia is a major obstacle toward understanding the disorder. One likely subtype is the deficit syndrome (DS) where patients suffer from predominantly negative symptoms. This study investigated the evoked responses and the evoked magnetic fields to identify the neurophysiological deviations associated with the DS. Ten subjects were recruited for each group (Control, DS, and Nondeficit schizophrenia [NDS]). Subjects underwent magnetoencephalography (MEG) and electroencephalography (EEG) testing while listening to an oddball paradigm to generate the P300 as well as a paired click paradigm to generate the mid-latency auditory-evoked responses (MLAER) in a sensory gating paradigm. MEG-coherence source imaging (CSI) during P300 task revealed a significantly higher average coherence value in DS than NDS subjects in the gamma band (30-80 Hz), when listening to standard stimuli but only NDS subjects had a higher average coherence level in the gamma band than controls when listening to the novel sounds. P50, N100, and P3a ERP amplitudes (EEG analysis) were significantly decreased in NDS compared with DS subjects. The data suggest that the deviations in the 2 patient groups are qualitatively different. Deviances in NDS patients suggest difficulty in both early (as in the gating paradigm), as well as later top-down processes (P300 paradigm). The main deviation in the DS group was an exaggerated responsiveness to ongoing irrelevant stimuli detected by EEG whereas NDS subjects had an exaggerated response to novelty.

The efficacy of cariprazine in negative symptoms of schizophrenia: Post hoc analyses of PANSS individual items and PANSS-derived factors

BACKGROUND

Negative symptoms in schizophrenia are heterogeneous and multidimensional; effective treatments are lacking. Cariprazine, a dopamine D₃-preferring D₃/D₂ receptor partial agonist and serotonin 5-HT_1A receptor partial agonist, was significantly more effective than risperidone in treating negative symptoms in a prospectively designed trial in patients with schizophrenia and persistent, predominant negative symptoms.

METHODS

Using post hoc analyses, we evaluated change from baseline at week 26 in individual items of the Positive and Negative Syndrome Scale (PANSS) and PANSS-derived factor models using a mixed-effects model for repeated measures (MMRM) in the intent-to-treat (ITT) population (cariprazine = 227; risperidone = 227).

RESULTS

Change from baseline was significantly different in favor of cariprazine versus risperidone on PANSS items N1-N5 (blunted affect, emotional withdrawal, poor rapport, passive/apathetic social withdrawal, difficulty in abstract thinking) (P < .05), but not on N6 (lack of spontaneity/flow of conversation) or N7 (stereotyped thinking). On all PANSS-derived negative symptom factor models evaluated (PANSS-Factor Score for Negative Symptoms, Liemburg factors, Khan factors, Pentagonal Structure Model Negative Symptom factor), statistically significant improvement was demonstrated for cariprazine versus risperidone (P < .01). Small and similar changes in positive/depressive/EPS symptoms suggested that negative symptom improvement was not pseudospecific. Change from baseline was significantly different for cariprazine versus risperidone on PANSS-based factors evaluating other relevant symptom domains (disorganized thoughts, prosocial function, cognition; P < .05).

CONCLUSIONS

Since items representing different negative symptom dimensions may represent different fundamental pathophysiological mechanisms, significant improvement versus risperidone on most PANSS Negative Subscale items and across all PANSS-derived factors suggests broad-spectrum efficacy for cariprazine in treating negative symptoms of schizophrenia.

The Use of Cognitive Screening in Pharmacotherapy Trials for Cognitive Impairment Associated With Schizophrenia

There are currently no regulatory approved pharmacological treatments for cognitive impairment associated with schizophrenia (CIAS). One possibility is that trial methodology itself is hindering their development. Emerging evidence suggests that patients with schizophrenia may show limited benefit from pro-cognitive interventions if they already exhibit intact cognitive performance, relative to normative thresholds. The aim of this report was to examine the extent to which objectively assessed cognitive performance has been used as an eligibility and/or stratification criterion in CIAS pharmacotherapy trials. On 16^th January 2019, we conducted a systematic search of studies listed on ClinicalTrials.gov to identify randomized, double-blind, placebo-controlled, add-on pharmacotherapy trials conducted in patients with a diagnosis of schizophrenia, in which a paper-and-pencil or computerized cognitive task (or battery) was specified as a primary outcome measure. Of the 87 trials that met our inclusion criteria, 10 (11.5%) required the presence of an objectively assessed cognitive deficit as part of their patient eligibility criteria. No studies reported stratifying patients according to the presence or degree of cognitive impairment they exhibited. These results suggest that the vast majority of CIAS trials may have been underpowered due to the inclusion of cognitively "normal" patients. Purposive screening for cognitive impairment could increase CIAS trial success.

Neurophysiological correlates of Avolition-apathy in schizophrenia: A resting-EEG microstates study

Background

The “Avolition-apathy” domain of the negative symptoms was found to include different symptoms by factor analytic studies on ratings derived by different scales. In particular, the relationship of anhedonia with this domain is controversial. Recently introduced negative symptom rating scales provide a better assessment of anhedonia, allowing the distinction of anticipatory and consummatory aspects, which might be related to different psychopathological dimensions. The study of associations with external validators, such as electrophysiological, brain imaging or cognitive indices, might shed further light on the status of anhedonia within the Avolition-apathy domain.

Objectives

We used brain electrical microstates (MSs), which represent subsecond periods of quasi-stable scalp electrical field, associated with resting-state neural networks (and thus with global patterns of functional connectivity), to test whether the component symptoms of Avolition-apathy share the same correlates.

Method

We analyzed multichannel resting EEGs in 142 individuals with schizophrenia (SCZ) and in 64 healthy controls (HC), recruited within the add-on EEG study of the Italian Network for Research on Psychoses. Relative time contribution, duration and occurrence of four MS classes (MS-A/-B/-C/−D) were calculated. Group differences on MS parameters (contribution and duration) and their associations with negative symptom domains (assessed using the Brief Negative Symptoms Scale) were investigated.

Results

SCZ, in comparison to HC, showed increased contribution and duration of MS-C. The contribution of MS-A positively correlated with Avolition-apathy, but not with Expressive deficit. Within the Avolition-apathy domain, anticipatory anhedonia, avolition and asociality, but not consummatory anhedonia, showed the same correlations with MS-A contribution.

Conclusion

Our findings support the existence of distinct electrophysiological correlates of Avolition-apathy with respect to Expressive deficit, and lend support to the hypothesis that only the anticipatory component of anhedonia shares the same pathophysiological underpinnings of the Avolition-apathy domain.

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Microstate C contribution and duration were increased in SCZ compared to HC.

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Avolition-apathy was correlated with the contribution of microstate A.

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Avolition-apathy might be associated with sensory processing deficit.