Negative symptom domain prevalence across diagnostic boundaries: The relevance of diagnostic shifts

Efficacy of 5-HT2A antagonists on negative symptoms in patients with schizophrenia: A meta-analysis

Negative symptoms have a major impact on the prognosis of schizophrenia, but have proven more difficult to improve or treat with antipsychotic medication. The aim of this meta-analysis is to evaluate the efficacy of 5-HT2A antagonist treatments on negative symptoms in patients with schizophrenia. After a systematic search, all randomized, double-blind and placebo-controlled trials evaluating the efficacy of 5-HT2A antagonists were included. Standardized mean differences were calculated between quantitative data from treatment and placebo groups, and odds ratios were calculated between qualitative data from treatment and placebo groups. Ten studies were included in the analysis. A significantly greater decrease in negative symptoms and global symptomatology was found in the 5-HT2A antagonist group compared with the placebo group, but no difference was found for positive symptoms. At the end of the studies, a lower extra-pyramidal symptoms score was found in the 5-HT2A antagonist group. No significant difference was found for the drop-out rate or for the rate of serious adverse effects, but a higher rate of treatment-emergent adverse effects was found in the 5-HT2A antagonist group. Our meta-analysis shows that 5-HT2A antagonists demonstrate a favorable benefit/risk profile and could be useful in the treatment of negative symptoms in patients with schizophrenia.

The trajectory of two negative symptom dimensions in first-episode psychosis and the role of cannabis use: A 10-year follow-up study

OBJECTIVE

To investigate the trajectories of diminished expression and apathy over 10 years. Further, to explore the effects of baseline- and persistent cannabis use on the development of diminished expression and apathy during follow-up, while controlling other potential sources and predictors of secondary negative symptoms.

METHODS

351 participants with a first episode of non-affective psychosis were examined at baseline and invited to follow-up at one year and 10 years. The trajectories of diminished expression and apathy were investigated using linear mixed models. Subsequently, cannabis use and other potential predictors and sources of secondary negative symptoms were added to the model to investigate the respective impact on their trajectories.

RESULTS

The severity of both diminished expression and apathy decreased during the follow-up period after the first episode of psychosis, with the most improvement observed from baseline to 1-year follow-up. Cannabis use at baseline was associated with a long-lasting higher symptom load for diminished expression, but not apathy. Introducing persistent cannabis use to the model further strengthened the association with diminished expression.

CONCLUSION

Both cannabis use at baseline and persistent cannabis use after a first episode of psychosis were associated with more severe symptoms of diminished expression. Our results imply a causal relationship between cannabis use and diminished expression and suggest that measures to reduce cannabis use both before and after psychosis onset may reduce expressive negative symptoms.

Updated perspectives on the clinical significance of negative symptoms in patients with schizophrenia

INTRODUCTION

Negative symptoms in schizophrenia are associated with poor response to available treatments, poor quality of life, and functional outcome. Therefore, they represent a substantial burden for people with schizophrenia, their families, and health-care systems.

AREAS COVERED

In this manuscript, we will provide an update on the conceptualization, assessment, and treatment of this complex psychopathological dimension of schizophrenia.

EXPERT OPINION

Despite the progress in the conceptualization of negative symptoms and in the development of state-of-the-art assessment instruments made in the last decades, these symptoms are still poorly recognized, and not always assessed in line with current conceptualization. Every effort should be made to disseminate the current knowledge on negative symptoms, on their assessment instruments and available treatments whose efficacy is supported by research evidence. Longitudinal studies should be promoted to evaluate the natural course of negative symptoms, improve our ability to identify the different sources of secondary negative symptoms, provide effective interventions, and target primary and persistent negative symptoms with innovative treatment strategies. Further research is needed to identify pathophysiological mechanisms of primary negative symptoms and foster the development of new treatments.

The trajectories and correlates of two negative symptom subdomains in first-episode schizophrenia

BACKGROUND

Recent studies suggest a two-factor structure for negative symptoms as assessed by the Positive and Negative Syndrome Scale (PANSS) in schizophrenia, namely experiential and expressive subdomains. Little is known about their clinical correlates and treatment trajectories.

OBJECTIVES

We sought to replicate the two factor-analysis derived subdomains for PANSS negative symptoms in schizophrenia and to assess their independent demographic, premorbid and treatment-related characteristics.

METHODS

This was a longitudinal study of 106 minimally treated participants with a first episode of a schizophrenia spectrum disorder who received treatment with flupenthixol decanoate 2-weekly injections over two years. Factor analysis was used to characterize the PANSS negative symptom subdomains and linear mixed-effect models for continuous repeated measures were constructed to assess the temporal relations between the negative symptom subdomains and premorbid and treatment related variables.

RESULTS

Factor analysis confirmed a two-factor solution for experiential and expressive subdomains of negative symptoms, although they were strongly correlated. The treatment response trajectories for the two subdomains did not differ significantly, and neither subdomain was significantly associated with our premorbid variables. We found significant main effects for disorganised symptoms and extrapyramidal symptoms on the expressive subdomain, and for disorganised symptoms and depressive symptoms on the experiential subdomain. Post-hoc testing indicated that reductions in HDL-cholesterol levels were associated with less improvement in both expressive and experiential subdomain scores.

CONCLUSION

The two negative symptom subdomains are closely related, have similar premorbid correlates and respond similarly to antipsychotic treatment. Depression affects the experiential subdomain, whereas extrapyramidal symptoms affect the expressive subdomain.

Phosphodiesterase as a Target for Cognition Enhancement in Schizophrenia

Schizophrenia is a severe mental disorder that affects more than 1% of the population worldwide. Dopamine system dysfunction and alterations in glutamatergic neurotransmission are strongly implicated in the aetiology of schizophrenia. To date, antipsychotic drugs are the only available treatment for the symptoms of schizophrenia. These medications, which act as D2-receptor antagonist, adequately address the positive symptoms of the disease, but they fail to improve the negative symptoms and cognitive impairment. In schizophrenia, cognitive impairment is a core feature of the disorder. Therefore, the treatment of cognitive impairment and the other symptoms related to schizophrenia remains a significant unmet medical need. Currently, phosphodiesterases (PDEs) are considered the best drug target for the treatment of schizophrenia since many PDE subfamilies are abundant in the brain regions that are relevant to cognition. Thus, this review aims to illustrate the mechanism of PDEs in treating the symptoms of schizophrenia and summarises the encouraging results of PDE inhibitors as anti-schizophrenic drugs in preclinical and clinical studies.

EPA guidance on assessment of negative symptoms in schizophrenia

Background

During the last decades, a renewed interest for negative symptoms (NS) was brought about by the increased awareness that they interfere severely with real-life functioning, particularly when they are primary and persistent.

Methods

In this guidance paper, we provide a systematic review of the evidence and elaborate several recommendations for the conceptualization and assessment of NS in clinical trials and practice.

Results

Expert consensus and systematic reviews have provided guidance for the optimal assessment of primary and persistent negative symptoms; second-generation rating scales, which provide a better assessment of the experiential domains, are available; however, NS are still poorly assessed both in research and clinical settings.

This European Psychiatric Association (EPA) guidance recommends the use of persistent negative symptoms (PNS) construct in the context of clinical trials and highlights the need for further efforts to make the definition of PNS consistent across studies in order to exclude as much as possible secondary negative symptoms. We also encourage clinicians to use second-generation scales, at least to complement first-generation ones.

The EPA guidance further recommends the evidence-based exclusion of several items included in first-generation scales from any NS summary or factor score to improve NS measurement in research and clinical settings. Self-rated instruments are suggested to further complement observer-rated scales in NS assessment.

Several recommendations are provided for the identification of secondary negative symptoms in clinical settings.

Conclusions

The dissemination of this guidance paper may promote the development of national guidelines on negative symptom assessment and ultimately improve the care of people with schizophrenia.

Family History of Psychiatric Disorders and Clinical Factors Associated With a Schizophrenia Diagnosis

Background

Schizophrenia (SCH) and bipolar disorder (BD) have both shared and unique genetic risk factors and clinical characteristics. The aim of the present study was to identify potential risk factors significantly associated with SCH, relative to a BD reference group.

Methods

Data were obtained from medical records of patients that entered a major Mexico City hospital during 2009–2010 presenting psychotic symptoms (n = 1132; 830 cases of SCH, 302 cases of BD; 714 men and 418 women). SCH and BD diagnoses were compared with respect to a number of family and clinical characteristics. Logistic and linear regression analyses were used to respectively identify factors selectively associated with the SCH diagnosis relative to the BD diagnosis and explore the relationship between PANSS scores and parental age at time of birth to the age of SCH onset.

Results

Patients with SCH showed greater functional impairment than those with BD. Family history of mental illness, premorbid schizoid-like personality, and obstetric trauma were significantly associated with the SCH diagnosis. The association of obstetric trauma with SCH was greatest in male patients with a family history of mental illness. In women, increased paternal and decreased maternal age at time of the patient’s birth were associated with an earlier age of SCH onset.

Conclusion

Male gender, showing premorbid schizoid-like personality, familial SCH, and obstetric trauma are risk factors that distinguish SCH from BD. Additionally, our results suggest that risk for SCH relative to BD may be importantly influenced by interactions between familial risk, gender, and obstetric trauma.

The Prevalence of Negative Symptoms Across the Stages of the Psychosis Continuum

BACKGROUND

Patients in every stage of the psychosis continuum can present with negative symptoms. While no treatment is currently available to address these symptoms, a more refined characterization of their course over the lifetime could help in elaborating interventions. Previous reports have separately investigated the prevalence of negative symptoms within each stage of the psychosis continuum. Our aim in this review is to compare those prevalences across stages, thereby disclosing the course of negative symptoms.

METHODS

We searched several databases for studies reporting prevalences of negative symptoms in each one of our predetermined stages of the psychosis continuum: clinical or ultra-high risk (UHR), first-episode of psychosis (FEP), and younger and older patients who have experienced multiple episodes of psychosis (MEP). We combined results using the definitions of negative symptoms detailed in the Brief Negative Symptom Scale, a recently developed tool. For each negative symptom, we averaged and weighted by the combined sample size the prevalences of each negative symptom at each stage.

RESULTS

We selected 47 studies totaling 1872 UHR, 2947 FEP, 5039 younger MEP, and 669 older MEP patients. For each negative symptom, the prevalences showed a comparable course. Each negative symptom decreased from the UHR to FEP stages and then increased from the FEP to MEP stages.

CONCLUSIONS

Certain psychological, environmental, and treatment-related factors may influence the cumulative impact of negative symptoms, presenting the possibility for early intervention to improve the long-term course.

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.

Negative symptoms in first-episode psychosis: Clinical correlates and 1-year follow-up outcomes in London Early Intervention Services

AIM

Negative symptoms (NS) have been associated with poor outcome and remain difficult to treat in patients with psychosis. This study examined the association of NS with clinical features at first presentation to mental health services for psychosis and with outcomes at 1-year follow-up.

METHODS

Clinical data were utilized from five London Early Intervention Services (EIS) included in the MiData audit database. The sample comprised 484 first-episode psychosis patients with complete Positive and Negative Syndrome Scale data at baseline and 1-year follow-up. Multiple imputation (N = 50) was conducted to account for missing follow-up data.

RESULTS

Baseline NS were associated with male gender (B = -1.63, P < .05), younger age at onset (B = -.15, P <. 05), a higher level of impairment on the Global Assessment of Functioning (disability) Scale at baseline (B = -.19, P <. 010), an absence of reported substance misuse prior to baseline assessment (B = -3.05, P <. 001) and unemployment at baseline (B = -.93, P <. 01). At 1-year follow-up, NS at presentation were associated with worse Global Assessment of Functioning Scale for symptom (B = -.28, P < .01) and disability (B = -.27, P <. 05) and with hospital admission (OR = 1.06, P < .01).

CONCLUSIONS

Negative symptoms at presentation to EIS were associated with worse functioning at entry and poorer outcomes 1 year later. Future research is required to better understand the aetiology and trajectories of NS in early psychosis and propose novel targeted interventions.

Disagreement between service-users and clinicians assessment of physical health during early psychosis

AIMS

Physical illnesses account for the majority of excess deaths following psychosis; access to care and treatment is inequitable and schizophrenia has now been dubbed the life-shortening disease. We compared service-users and clinician's perspectives of their physical health assuming that one of the fundamental issues in prompting screening and treatment is the view that health is poor.

METHODS

Data comprising sample characteristics, diagnosis, symptoms, insight, antecedents to psychosis and physical health perspectives were obtained prospectively as part of a larger epidemiological study of first-episode psychosis. We compared physical health perspectives between service-users and clinicians and examined clinical correlates.

RESULTS

Contrary to our expectations, we found that service-users reported poorer physical health over time than clinicians did.

CONCLUSION

Reconciling service-users and clinician's views of physical health may be an important step towards collaborative care and improving access to better quality healthcare for serious mental illness.

Consequences of persistent depression and apathy in first-episode psychosis - A one-year follow-up study

BACKGROUND

Apathy and depression are prevalent in first-episode psychosis (FEP), have overlapping clinical features and are linked to social dysfunction, with indications that persisting symptoms have an even more negative impact. Our objective was to investigate the prevalence of persisting depression (PD), persisting apathy (PA), to what extent they overlap and their relative associations to functioning during a one-year follow-up.

METHODS

One hundred and twenty-five participants with a FEP were recruited, and 88 (70%) were reassessed at follow-up. Functional outcome was assessed with the Global Assessment of Functioning Scale-split version, functioning sub-scale, apathy with the Apathy Evaluation Scale, Clinician version (AES-C), and depression with the Calgary Depression Scale for Schizophrenia (CDSS). Persisting depression was defined as a CDSS sum-score > 7 at baseline and follow-up, and persisting apathy as an AES-C sum-score ≥ 27 at baseline and follow-up. Multiple linear regression analyses were used to investigate symptoms' contributions to functioning. Differences in functioning between groups were explored with Kruskal-Wallis test and Mann-Whitney U test.

RESULTS

We found PD in 17 (19%) and PA in 28 (32%) of participants. The likelihood of PD was increased if PA was also present (p = 0.008, phi = 0.28). Ten participants (11%) experienced overlapping PD and PA. Participants with PD (r = -0.38, p = 0.004), PA (r = -0.51, p < 0.000) or both (r = -0.52, p < 0.000) had poorer functioning at follow-up than participants without persisting symptoms.

CONCLUSION

PD, PA and overlapping PD/PA is highly prevalent and associated with severely impaired functioning in FEP. Correct identification of these patients is a prerequisite for initiating relevant treatment early in the course of illness.

Negative symptoms of psychosis: A life course approach and implications for prevention and treatment

AIM

Negative symptoms are a cause of enduring disability in serious mental illness. In spite of this, the development of effective treatments for negative symptoms has remained slow. The challenge of improving negative symptom outcomes is compounded by our limited understanding of their aetiology and longitudinal development.

METHODS

A literature search was conducted for life course approach of negative symptoms using PubMed. Further articles were included following manual checking of reference lists and other search strategies. The paper contains a theoretical synthesis of the literature, summarized using conceptual models.

RESULTS

Negative symptom definitions are compared and considered within a context of the life course. Previous studies suggest that several illness phases may contribute to negative symptoms, highlighting our uncertainty in relation to the origin of negative symptoms.

CONCLUSIONS

Similar to other aspects of schizophrenia, negative symptoms likely involve a complex interplay of several risk and protective factors at different life phases. Concepts suggested in this article, such as "negative symptom reserve" theory, require further research, which may inform future prevention and treatment strategies.

Predictors of change in social networks, support and satisfaction following a first episode psychosis: A cohort study

BACKGROUND

Diminished social networks are common in psychosis but few studies have measured these comprehensively and prospectively to determine how networks and support evolve during the early phase. There is little information regarding perceived support in the early phase of illness. The aim of this study was to describe social support, networks and perceived satisfaction, explore the clinical correlates of these outcomes and examine whether phases of untreated psychosis are linked with social network variables to determine potential opportunities for intervention.

METHODS

During the study period, we assessed 222 people with first-episode psychosis at entry into treatment using valid and reliable measures of diagnosis, positive and negative symptoms, periods of untreated psychosis and prodrome and premorbid adjustment. For follow-up we contacted participants to conduct a second assessment (n=158). There were 97 people who participated which represented 61% of those eligible. Social network and support information obtained at both time points included the number of friends, self-reported satisfaction with support and social network size and clinician's evaluation of the degree of support received through networks. Mixed effects modelling determined the contribution of potential explanatory variables to social support measured.

RESULTS

A number of clinical variables were linked with social networks, support and perceived support and satisfaction. The size of networks did not change over time but those with no friends and duration of untreated psychosis was significantly longer for those with no friends at entry into treatment (n=129, Median=24.5mths, IQR=7.25-69.25; Mann-Whitney U=11.78, p=0.008). Social support at baseline and at one year was predicted by homelessness (t=-2.98, p=0.001, CI -4.74 to -1.21), duration of untreated psychosis (t=-0.86, p=0.031, CI -1.65 to -0.08) and premorbid adjustment (t=-2.26, p=0.017, CI -4.11 to -0.42). Social support improved over time but the duration of untreated psychosis was not linked with the rate of improvement in this outcome.

CONCLUSIONS

Improved social support could indicate greater reliance on social support or becoming more adept at mobilising resources to meet social needs. Particularly vulnerable groups with very long duration of untreated psychosis confirm the need for earlier intervention or targeted social network interventions to preserve social connectedness.

Individual negative symptoms and domains - Relevance for assessment, pathomechanisms and treatment

The negative symptoms of schizophrenia can be divided into two domains. Avolition/apathy includes the individual symptoms of avolition, asociality and anhedonia. Diminished expression includes blunted affect and alogia. Until now, causes and treatment of negative symptoms have remained a major challenge, which is partially related to the focus on negative symptoms as a broad entity. Here, we propose that negative symptoms may become more tractable when the different domains and individual symptoms are taken into account. There is now increasing evidence that the relationship with clinical variables - in particular outcome - differs between the domains of avolition/apathy and diminished expression. Regarding models of negative symptom formation, those relevant to avolition/apathy are now converging on processes underlying goal-directed behavior and dysfunctions of the reward system. In contrast, models of the diminished expression domains are only beginning to emerge. The aim of this article is to review the specific clinical, behavioral and neural correlates of individual symptoms and domains as a better understanding of these areas may facilitate specific treatment approaches.

Secondary negative symptoms - A review of mechanisms, assessment and treatment

Negative symptoms in schizophrenia may be classified as primary or secondary. Primary negative symptoms are thought to be intrinsic to schizophrenia, while secondary negative symptoms are caused by positive symptoms, depression, medication side-effects, social deprivation or substance abuse. Most of the research on secondary negative symptoms has aimed at ruling them out in order to isolate primary negative symptoms. However, secondary negative symptoms are common and can have a major impact on patient-relevant outcomes. Therefore, the assessment and treatment of secondary negative symptoms are clinically relevant. Furthermore, understanding the mechanisms underlying secondary negative symptoms can contribute to an integrated model of negative symptoms. In this review we provide an overview of concepts, evidence, assessment and treatment for the major causes of secondary negative symptoms. We also summarize neuroimaging research relevant to secondary negative symptoms. We emphasize the relevance of recent developments in psychopathological assessment of negative symptoms, such as the distinction between amotivation and diminished expression, which have only rarely been applied in research on secondary negative symptoms.

From neurological soft signs to functional outcome in young individuals in treatment with secondary services for non-psychotic disorders: a path analysis

BACKGROUND

Functional decline among patients with mental illness is not unique to individuals with psychotic disorders. Despite this, research on early predictors of functional outcome mainly focused on individuals thought to have an 'at risk mental state' (ARMS) for psychosis. There is evidence suggesting that certain early vulnerability markers, such as neurological soft signs (NSS), may explain variability in functional outcomes independent of the level of psychosis risk and the traditional diagnostic classification.

METHOD

Structural equation modeling was applied to baseline data from a prospective longitudinal study of 138 young individuals in treatment with secondary services for non-psychotic disorders. We evaluated theoretically based models of pathways to functional outcome starting from NSS. The intervening variables were established according to previous evidence and drawn from two general categories: cognition (neuro- and social-) and negative symptoms (expressive and experiential).

RESULTS

A final trimmed model was a single path running from NSS to neurocognition to experiential negative symptoms to outcome. It could not be improved by adding or dropping connections that would change the single path to multiple paths. The indirect effect from NSS to outcome was significant. The validity of the model was independent of the ARMS status and the psychiatric diagnosis.

CONCLUSIONS

Our results provide evidence for a single pathway model in which the starting and intervening variables represent modifiable trans-diagnostic therapeutic targets to improve functional trajectories in young individuals with a recent-onset psychiatric diagnosis and different levels of psychosis risk.