Treating Negative Symptoms in Schizophrenia: an Update. ACTA ACUST UNITED AC. 2016;3:133-150. [PMID: 27376016 PMCID: PMC4908169 DOI: 10.1007/s40501-016-0075-8]

Motivational Deficits in Schizophrenia Are Associated With Reduced Differentiation Between Gain and Loss-Avoidance Feedback in the Striatum

BACKGROUND

The current study was designed to test the hypothesis that motivational deficits in schizophrenia (SZ) are tied to a reduced ability to differentially signal gains and instances of loss-avoidance in the brain, leading to reduced ability to form adaptive representations of expected value.

METHODS

We administered a reinforcement learning paradigm to 27 medicated SZ patients and 27 control subjects in which participants learned three probabilistic discriminations. In regions of interest in reward networks identified a priori, we examined contrasts between trial types with different expected values (e.g., expected gain-nonmonetary) and between outcomes with the same prediction error valence but different experienced values (e.g., gain-loss-avoidance outcome, miss-loss outcome).

RESULTS

Both whole-brain and region of interest analyses revealed that SZ patients showed reduced differentiation between gain and loss-avoidance outcomes in the dorsal anterior cingulate cortex and bilateral anterior insula. That is, SZ patients showed reduced contrasts between positive prediction errors of different objective values in these areas. In addition, we observed significant correlations between gain-loss-avoidance outcome contrasts in the ventral striatum and ratings for avolition/anhedonia and between expected gain-nonmonetary contrasts in the ventral striatum and ventromedial prefrontal cortex.

CONCLUSIONS

These results provide further evidence for intact prediction error signaling in medicated SZ patients, especially with regard to loss-avoidance. By contrast, components of frontostriatal circuits appear to show reduced sensitivity to the absolute valence of expected and experienced outcomes, suggesting a mechanism by which motivational deficits may emerge.

Bitopertin in Negative Symptoms of Schizophrenia-Results From the Phase III FlashLyte and DayLyte Studies

BACKGROUND

There is currently no standard of care for treatment of negative symptoms of schizophrenia, although some previous results with glutamatergic agonists have been promising.

METHODS

Three (SunLyte [WN25308], DayLyte [WN25309], and FlashLyte [NN25310]) phase III, multicenter, randomized, 24-week, double-blind, parallel-group, placebo-controlled studies evaluated the efficacy and safety of adjunctive bitopertin in stable patients with persistent predominant negative symptoms of schizophrenia treated with antipsychotics. SunLyte met the prespecified criteria for lack of efficacy and was declared futile. Key inclusion criteria were age ≥18 years, DSM-IV-TR diagnosis of schizophrenia, score ≥40 on the sum of the 14 Positive and Negative Syndrome Scale negative symptoms and disorganized thought factors, unaltered antipsychotic treatment, and clinical stability. Following a 4-week prospective stabilization period, patients were randomly assigned 1:1:1 to bitopertin (5 mg and 10 mg [DayLyte] and 10 mg and 20 mg [FlashLyte]) or placebo once daily for 24 weeks. The primary efficacy end point was mean change from baseline in Positive and Negative Syndrome Scale negative symptom factor score at week 24.

RESULTS

The intent-to-treat population in DayLyte and FlashLyte included 605 and 594 patients, respectively. At week 24, mean change from baseline showed improvement in all treatment arms but no statistically significant separation from placebo in Positive and Negative Syndrome Scale negative symptom factor score and all other end points. Bitopertin was well tolerated.

CONCLUSIONS

These studies provide no evidence for superior efficacy of adjunctive bitopertin in any of the doses tested over placebo in patients with persistent predominant negative symptoms of schizophrenia.

Cariprazine: A Review in Schizophrenia

Cariprazine (Vraylar™) is a dopamine D₃-preferring D₂/D₃ receptor partial agonist indicated for the treatment of patients with schizophrenia. This narrative review summarizes pharmacological, efficacy and tolerability data relevant to the use of cariprazine in patients with this disorder. In 6-week, phase IIb and III trials in patients with schizophrenia, cariprazine was significantly more efficacious than placebo in improving schizophrenia symptoms, including improvements in Positive and Negative Syndrome Scale (PANSS) total scores. It was associated with a significantly longer time to relapse than placebo in a long-term, phase III, relapse-prevention study. Cariprazine was also significantly more efficacious than risperidone in improving PANSS Factor Score for Negative Symptoms in a phase III trial in patients with predominantly negative symptoms of schizophrenia, a typically difficult to treat group of patients. Cariprazine was generally well tolerated in clinical trials, with most adverse events being of mild to moderate severity, and metabolic changes observed were considered generally not clinically significant. Cariprazine is a useful addition to the treatment options for schizophrenia, and may be of particular use in patients with predominantly negative symptoms.

Cannabinoids as hippocampal network administrators

Extensive pioneering studies performed in the hippocampus have greatly contributed to our knowledge of an endogenous cannabinoid system comprised of the molecular machinery necessary to process endocannabinoid lipid messengers and their associated cannabinoid receptors. Moreover, a foundation of knowledge regarding the function of hippocampal circuits, and its role in supporting synaptic plasticity has facilitated our understanding of the roles cannabinoids play in the diverse behaviors in which the hippocampus participates, in both normal and pathological states. In this review, we present an historical overview of research pertaining to the hippocampal cannabinoid system to provide context in which to understand the participation of the hippocampus in cognition, behavior, and epilepsy. We also examine potential roles for the hippocampal formation in mediating dysfunctional behavior, and assert that these phenomena reflect disordered physiological activity within the hippocampus and its interactions with other brain regions after exposure to synthetic cannabinoids, and the phytocannabinoids found in marijuana, such as Δ⁹-THC and cannabidiol. In this regard, we examine contemporary hypotheses concerning the hippocampal endocannabinoid system's participation in psychotic disorders, schizophrenia, and epilepsy, and examine cannabinoid-sensitive cellular mechanisms contributing to coherent network oscillations as potential contributors to these disorders. This article is part of the Special Issue entitled "A New Dawn in Cannabinoid Neurobiology".

Effectiveness of family interventions on psychological distress and expressed emotion in family members of individuals diagnosed with first-episode psychosis: a systematic review

BACKGROUND

A critical period for persons with first-episode psychosis is the first two years after diagnosis, when they are at high risk of suicide attempts, violent behaviors and substance abuse. This period also has a great impact on the psychological distress of family members, particularly caregivers who either provide care or live with ill family members. In addition, the families also report feelings of being overwhelmed when accessing service facilities at this critical point. These consequences impact on the affective tone/atmosphere in the family, also referred to as so-called expressed emotion. In addition, expressed emotion research has indicated that the family atmosphere contributes to recurrent psychosis and lengthy hospital stays for patients in the initial phase. Therefore, family interventions aimed at reducing psychological distress and improving expressed emotion in families during this critical time are very important. Modern research has yielded international evidence addressing these outcomes, but little is known about which interventions are the most effective. Therefore, this review aimed to evaluate the effectiveness of these interventions.

OBJECTIVES

The objective of this review was to examine the effectiveness of family interventions on psychological distress and expressed emotion in family members of persons with first-episode psychosis (FEP).

INCLUSION CRITERIA TYPES OF PARTICIPANTS

Family members of persons with FEP and who had received treatment after being diagnosed within two years.

TYPES OF INTERVENTION(S)

Studies that examined interventions among family members of persons with FEP. Family interventions referred to any education, psychoeducation, communication, coping and problem-solving skills training and cognitive behavioral therapy that was provided to family members of persons with FEP.

OUTCOMES

Psychological distress and expressed emotions of those family members.

TYPES OF STUDIES

Randomized controlled trials, quasi-experimental studies, cohort studies and case-control studies.

SEARCH STRATEGY

The preliminary search was conducted in MEDLINE and CINAHL with keywords containing the title, abstract and subject description analysis as the first identification of related studies. An extensive search was conducted in other databases including ProQuest Dissertations and Theses, ScienceDirect, Scopus, PsychINFO, ThaiLIS and Thai National research databases. In addition, searches of reference lists and other manual searches were undertaken.

METHODOLOGICAL QUALITY

Studies were critically appraised by two independent reviewers for methodological validity prior to inclusion in the review using standardized critical appraisal instruments from the Joanna Briggs Institute.

DATA EXTRACTION

Data were extracted using the standardized data extraction tools from the Joanna Briggs Institute. The mean score and standard deviation (SD) were extracted for targets outcomes relating to psychological distress and expressed emotion.

DATA SYNTHESIS

Quantitative data could not be pooled due to the heterogeneity of the included studies. Data were synthesized based on the individual results from the three included studies and have been presented in a narrative format accompanied with tabulated data.

RESULTS

Data synthesis of the three individual studies indicated that there were no statistically significant interventions that address psychological distress and expressed emotion in family members who live with and care for persons with FEP. There is insufficient evidence available to evaluate the effect sizes for pooled outcomes.

CONCLUSION

Based on the results of this review, there is insufficient evidence to validate the effectiveness of family interventions on psychological distress and expressed emotion in family members who live with and care for persons with FEP. In addition, based on the individual primary studies, the implications for practice should be carefully considered.

Predictive Processing, Source Monitoring, and Psychosis

A comprehensive understanding of psychosis requires models that link multiple levels of explanation: the neurobiological, the cognitive, the subjective, and the social. Until we can bridge several explanatory gaps, it is difficult to explain how neurobiological perturbations can manifest in bizarre beliefs or hallucinations, or how trauma or social adversity can perturb lower-level brain processes. We propose that the predictive processing framework has much to offer in this respect. We show how this framework may underpin and complement source monitoring theories of delusions and hallucinations and how, when considered in terms of a dynamic and hierarchical system, it may provide a compelling model of several key clinical features of psychosis. We see little conflict between source monitoring theories and predictive coding. The former act as a higher-level description of a set of capacities, and the latter aims to provide a deeper account of how these and other capacities may emerge.

Effects of cognitive remediation therapy on neurocognition and negative symptoms in schizophrenia: an Italian naturalistic study

INTRODUCTION

Cognitive remediation therapy (CRT) has been reported to positively affect neurocognitive processes among patients with schizophrenia; however, the degree to which changes in cognition is linked to improved clinical symptoms, remains poorly understood. The current study aimed to investigate whether cognitive gains were associated to improvements in negative symptoms' severity in patients with schizophrenia living in two Italian psychiatric facilities.

METHODS

Patients with a diagnosis of schizophrenia were consecutively assigned to CRT (n = 33) and compared with an historical control group (n = 28). Assessments were performed at baseline and post-treatment using a neuropsychological battery (Trail Making Test A and B, Self-Ordered Pointing Task, California Verbal Learning Test), along with clinical and functioning measures.

RESULTS

Visual attention (TMT-A score change) was found as the only significant predictor of improvement in negative symptoms subscale of the Positive and Negative Syndrome Scale. Furthermore, a mediation path analysis confirmed that better performance in visual attention acts as mediator of the positive association between CRT intervention and lower post-treatment negative symptoms score.

CONCLUSIONS

CRT can have a positive impact on a measure of visual attention in patients with schizophrenia and on negative symptoms reduction that is mediated by this significant intervention effect.

Healthcare resource use in schizophrenia, EuroSC findings

Background: It is unclear if the burden associated with schizophrenia is affected by the type and severity of patient's symptoms. Objective: This study aims to quantify healthcare resource use associated with different profiles of schizophrenia symptoms. Study design: Post-hoc analysis of data from a naturalistic follow-up study. Setting: Secondary psychiatric services in France, Germany and the UK. Patients: EuroSC cohort:, representative sample of 1,208 schizophrenia patients Main outcome measure: We classified patients into eight health states, according to the Lenert classification (HS1-HS8), and estimated 6-month healthcare resource use (outpatient and day clinic visits, and hospitalisations) across the health states. Results: Approximately half of the patients were classed as having mild symptoms (HS1), with around 20% experiencing moderate, predominantly negative symptoms (HS2). The remaining health states were represented by <10% of patients each. Very few patients experienced extremely severe symptoms (HS8). No health state was associated with excess utilisation across all resource types. In terms of outpatient visits, patients were estimated to see a psychiatrist most often (3.01-4.15 visits over 6 months). Hospital admission was needed in 11%(HS1) - 35%(HS8) of patients and inpatient stays were generally prolonged for all health states (39-57 days). The average number of inpatient days was highest for patients in HS8 (18.17 days), followed by patients with severe negative symptoms (HS4; 13.37 days). In other health states characterised by severe symptoms (HS5-HS7), the average number of inpatient days was approximately half of those seen for HS4 (6.09-7.66). Conclusion: While none of the symptom profiles was associated with excess resource usage, hospitalization days were highest for HS with severe, predominantly negative or extremely severe symptoms. Patients with predominantly negative, moderate or severe symptoms appeared to have a high number of psychologist visits - an interesting finding that may reflect a specific therapeutic approach to the treatment of these patients.

Monoaminergic and Histaminergic Strategies and Treatments in Brain Diseases

The monoaminergic systems are the target of several drugs for the treatment of mood, motor and cognitive disorders as well as neurological conditions. In most cases, advances have occurred through serendipity, except for Parkinson's disease where the pathophysiology led almost immediately to the introduction of dopamine restoring agents. Extensive neuropharmacological studies first showed that the primary target of antipsychotics, antidepressants, and anxiolytic drugs were specific components of the monoaminergic systems. Later, some dramatic side effects associated with older medicines were shown to disappear with new chemical compounds targeting the origin of the therapeutic benefit more specifically. The increased knowledge regarding the function and interaction of the monoaminergic systems in the brain resulting from in vivo neurochemical and neurophysiological studies indicated new monoaminergic targets that could achieve the efficacy of the older medicines with fewer side-effects. Yet, this accumulated knowledge regarding monoamines did not produce valuable strategies for diseases where no monoaminergic drug has been shown to be effective. Here, we emphasize the new therapeutic and monoaminergic-based strategies for the treatment of psychiatric diseases. We will consider three main groups of diseases, based on the evidence of monoamines involvement (schizophrenia, depression, obesity), the identification of monoamines in the diseases processes (Parkinson's disease, addiction) and the prospect of the involvement of monoaminergic mechanisms (epilepsy, Alzheimer's disease, stroke). In most cases, the clinically available monoaminergic drugs induce widespread modifications of amine tone or excitability through neurobiological networks and exemplify the overlap between therapeutic approaches to psychiatric and neurological conditions. More recent developments that have resulted in improved drug specificity and responses will be discussed in this review.