Longitudinal progression of negative symptoms in schizophrenia: a new look at an old problem

Comparison of Negative Symptom Network Structures Between Patients With Early and Chronic Schizophrenia: A Network and Exploratory Graph Analysis

BACKGROUND AND HYPOTHESIS

Despite the clinical relevance of negative symptoms in schizophrenia, our understanding of negative symptoms remains limited. Although various courses and stages of schizophrenia have been identified, variations in the negative symptom networks between distinct stages of schizophrenia remain unexplored.

STUDY DESIGN

We examined 405 patients with early schizophrenia (ES) and 330 patients with chronic schizophrenia (CS) using the Scale for the Assessment of Negative Symptoms. Network analysis and exploratory graph analysis were used to identify and compare the network structures and community memberships of negative symptoms between the two groups. Further, associations between communities and social functioning were evaluated. The potential influences of other symptom domains and confounding factors were also examined.

STUDY RESULTS

Multidimensional differences were found in the networks of negative symptoms between ES and CS. The global connectivity strength was higher in the network of ES than in the network of CS. In ES, central symptoms were mainly related to expressive deficits, whereas in CS they were distributed across negative symptom domains. A three-community structure was suggested across stages but with different memberships and associations with social functioning. Potential confounding factors and symptom domains, including mood, positive, disorganization, and excitement symptoms, did not affect the network structures.

CONCLUSION

Our findings revealed the presence of stage-specific network structures of negative symptoms in schizophrenia, with negative symptom communities having differential significance for social functioning. These findings provide implications for the future development of tailored interventions to alleviate negative symptoms and improve functionality across stages.

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.

A cognitive model of diminished expression in schizophrenia: The interface of metacognition, cognitive symptoms and language disturbances

The resistance of negative symptoms to pharmacologic treatment has spurred interest in understanding the psychological factors that contribute to their formation and persistence. However, little is understood about the psychological processes that reinforce and sustain the negative symptoms domain of diminished expression. Prior research has shown that higher levels of diminished expression relate to deficits in metacognitive capacity. We propose a more complex model in which diminished expression occurs when impairments in metacognitive self-reflectivity, alterations in higher-order language structure, and cognitive symptoms interact and thus interfere with persons' ability to understand and express emotions in ways others can recognize. Individuals with schizophrenia-spectrum disorders (N = 201) provided personal narratives detailing their life story and reflections about their mental illness. Self-reflectivity was measured with the Metacognition Assessment Scale-Abbreviated, and situation models were extracted from participants' personal narratives via Coh-Metrix 3.0, an automated program that calculates language indices. Diminished expression and cognitive symptoms were measured with the Positive and Negative Syndrome Scale. Structural equation models (SEM) examined whether self-reflectivity mediated the impact of cognitive symptoms and situation models on diminished expression. Results of the SEM revealed that self-reflectivity partially mediated the impact of situation models on diminished expression (β = -.073, p = .008, ±95% CI [-0.126, -0.019]). and fully mediated the influence of cognitive symptoms in diminished expression (β = 0.099, p = .001, ±95% CI [0.038, 0.160]). In conclusion, results suggest that self-reflectivity, linguistic cohesion, and cognitive symptoms may be useful targets for intervention in efforts to treat diminished expression in psychosis.

Alterations in facial expressivity in youth at clinical high-risk for psychosis

Negative symptoms, such as blunted facial affect, are core features of psychotic disorders that predict poor functional outcome. However, it is unknown whether these impairments occur prior to the onset of psychosis. Understanding this phenomenon in the psychosis risk period has significant relevance for elucidating pathogenic processes, as well as potential for informing a viable new behavioral marker for broader social dysfunction and clinical course. The current study sought to determine the nature of facial expression deficits among individuals at clinical high-risk (CHR) for developing psychosis using a comprehensive approach, incorporating clinical interview ratings and automated facial expression coding analysis. A total of 42 CHR and 42 control participants completed clinical interviews and digitally taped segments were submitted into an automated, computerized tool to assess for 7 facial expressions (joy, anger, surprise, fear, contempt, disgust, sadness). Furthermore, relationships between facial expressions and social functioning and available scores on a psychosis conversion risk calculator from a total of 78 participants (39 CHR and 39 controls) were examined. Relationships between measures were also investigated (data was available for the Prodromal Inventory of Negative Symptoms among 33 CHR and 25 controls). Findings from clinical interview indicated that the CHR group exhibited elevated blunting. Furthermore, automated analyses showed that the CHR group displayed blunting in expressions of joy but surprisingly, increased anger facial expressions. Lastly, irregularities in facial expressions were related to decreased social functioning and increased psychosis conversion risk calculator scores, signaling heightened likelihood of conversion to psychosis. These findings suggest that alterations in facial expressivity occur early in the pathogenesis of psychosis and provide evidence for the efficacy of higher resolution measures of facial expressivity in psychosis research. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Evidence for two distinct domains of negative symptoms: Confirming the factorial structure of the CAINS

Negative symptoms are an important predictor of course of illness as well as social and occupational functioning. Clinically effective interventions are scarce. For negative symptoms to become a reliable primary endpoint in treatment studies, clear operationalization and construct validation is needed. Recent factor analyses mostly find two main factors for negative symptoms: diminished expression und amotivation/anhedonia. The Clinical Assessment Interview for Negative Symptoms (CAINS) consists of the subscales "motivation and pleasure" and "expression". We assessed three samples of subjects with schizophrenia (n = 105) for different aspects of the scale's reliability and validity. A confirmatory factor analysis (CFA) of the CAINS confirmed its two-factorial structure. The subscales had distinct correlational profiles: "Motivation and pleasure" was strongly associated with functional outcome and depression and further with neurocognition, positive symptoms and social cognition. "Expression" seems independent of sources of secondary negative symptoms and neurocognition. We found good internal consistency and interrater agreement. Test-retest reliability (two-week interval) was moderate for the CAINS and its "expression" subscale and low for the "motivation and pleasure" subscale. Our findings indicate that the CAINS differentiates reliably between the two main domains of negative symptoms with some questions remaining concerning the validity of the "motivation and pleasure" subscale.

Measuring pathology using the PANSS across diagnoses: Inconsistency of the positive symptom domain across schizophrenia, schizoaffective, and bipolar disorder

Although the Positive and Negative Syndrome Scale (PANSS) was developed for use in schizophrenia (SZ), antipsychotic drug trials use the PANSS to measure symptom change also for bipolar (BP) and schizoaffective (SA) disorder, extending beyond its original indications. If the dimensions measured by the PANSS are different across diagnoses, then the same score change for the same drug condition may have different meanings depending on which group is being studied. Here, we evaluated whether the factor structure in the PANSS was consistent across schizophrenia (n = 3647), bipolar disorder (n = 858), and schizoaffective disorder (n = 592). Along with congruency coefficients, Hancock's H, and Jaccard indices, we used target rotations and statistical tests of invariance based on confirmatory factor models. We found the five symptom dimensions measured by the 30-item PANSS did not generalize well to schizoaffective and bipolar disorders. A model based on an 18-item version of the PANSS generalized better across SZ and BP groups, but significant problems remained in generalizing some of the factors to the SA sample. Schizophrenia and bipolar disorder showed greater similarity in factor structure than did schizophrenia and schizoaffective disorder. The Anxiety/Depression factor was the most consistent across disorders, while the Positive factor was the least consistent.

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.

Prediction of motivational impairment: 12-month follow-up of the randomized-controlled trial on extended early intervention for first-episode psychosis

BACKGROUND

Amotivation is prevalent in first-episode psychosis (FEP) patients and is a major determinant of functional outcome. Prediction of amotivation in the early stage of psychosis, however, is under-studied. We aimed to prospectively examine predictors of amotivation in FEP patients in a randomized-controlled trial comparing a 1-year extension of early intervention (Extended EI, 3-year EI) with step-down psychiatric care (SC, 2-year EI).

METHODS

One hundred sixty Chinese patents were recruited from a specialized EI program for FEP in Hong Kong after they have completed this 2-year EI service, randomly allocated to Extended EI or SC, and followed up for 12 months. Assessments on premorbid adjustment, onset profiles, baseline symptom severity and treatment characteristics were conducted. Data analysis was based on 156 subjects who completed follow-up assessments.

RESULTS

Amotivation at 12-month follow-up was associated with premorbid adjustment, allocated treatment condition, and levels of positive symptoms, disorganization, amotivation, diminished expression (DE) and depression at study intake. Hierarchical multiple regression analysis revealed that Extended EI and lower levels of DE independently predicted better outcome on 12-month amotivation.

CONCLUSION

Our findings indicate a potentially critical therapeutic role of an extended specialized EI on alleviating motivational impairment in FEP patients. The longer-term effect of Extended EI on amotivation merits further investigation.

The course of negative symptom in first episode psychosis and the relationship with social recovery

AIMS

To investigate trajectories of negative symptoms during the first 12months of treatment for first episode psychosis (FEP), their predictors and relationship to social recovery.

METHOD

1006 participants were followed up for 12months following acceptance into Early Intervention in Psychosis services. Negative symptom trajectories were modelled using latent class growth analysis (LCGA) and predictors of trajectories examined using multinomial regression. Social recovery trajectories - also modelled using LCGA - of members of each negative symptom trajectory were ascertained and the relationship between negative symptom and social recovery trajectories examined.

RESULTS

Four negative symptom trajectories were identified: Minimal Decreasing (63.9%), Mild Stable (13.5%), High Decreasing (17.1%) and High Stable (5.4%). Male gender and family history of non-affective psychosis predicted stably high negative symptoms. Poor premorbid adolescent adjustment, family history of non-affective psychosis and baseline depression predicted initially high but decreasing negative symptoms. Members of the Mild Stable, High Stable and High Decreasing classes were more likely to experience stably low functioning than the Minimal Decreasing class.

CONCLUSIONS

Distinct negative symptom trajectories are evident in FEP. Only a small subgroup present with persistently high levels of negative symptoms. A substantial proportion of FEP patients with elevated negative symptoms at baseline will achieve remission of these symptoms within 12months. However, elevated negative symptoms at baseline, whether or not they remit, are associated with poor social recovery, suggesting targeted interventions for service users with elevated baseline negative symptoms may help improve functional outcomes.

The course of negative symptoms over the first five years of treatment: Data from an early intervention program for psychosis

BACKGROUND

Cross-sectional studies suggest that negative symptoms are constituted by separable domains of reduced expressiveness and reduced motivation, but there is little data on the longitudinal course of these symptoms. We examined evidence for differences in the course and correlates of these two domains in a prospective study of patients presenting with a first episode of psychosis.

METHODS

Of 132 patients who were followed up for five years, it was possible to monitor reduced expressiveness and motivation on a weekly basis for 127. Information on treatment delay, premorbid adjustment, intellectual functioning, anxiety, depression and psychosocial functioning were also collected.

RESULTS

Over the five year follow-up, symptoms of reduced motivation occurred in 95.3% of patients and reduced expressiveness in 68.5%; and deficits in motivation were more likely to be unremitting (15.7%) than expressive deficits (5.5%). There were differences in the correlates of the proportion of time each patient experienced symptoms of each domain. Depression, weeks of full time occupation and weeks on a disability pension were associated with both domains. Anxiety was associated only with diminished motivation. Lower performance IQ; extrapyramidal symptoms (EPS) and dysrhythmic EEG were associated only with proportion of time showing reduced expressiveness.

CONCLUSIONS

The prospective data support previous cross-sectional findings that, while these domains of negative symptoms are correlated, they do show differences in prevalence over time and in their correlates.

Negative symptoms and executive function in schizophrenia: does their relationship change with illness duration?

BACKGROUND

Negative symptoms and cognitive dysfunction are of crucial functional and prognostic importance in schizophrenia. However, the nature of the relationship between them and the factors that may influence it have not been well established.

AIMS

To investigate whether the relationship between negative symptoms and executive function changes according to the duration of illness in schizophrenia.

METHODS

The Positive and Negative Syndrome Scale was used to assess psychopathology and the Wisconsin Card Sorting Test (WCST) to evaluate executive function in a sample of 200 schizophrenic patients who were classified in 3 groups according to their duration of illness: up to 5 years (short duration group), 6-20 years (intermediate duration group) and over 20 years of illness (long duration group).

RESULTS

Medium-sized correlations were found between negative symptoms and WCST performance as assessed by the number of completed categories in all 3 groups. However, differences were found according to the duration of schizophrenia. For patients in the short duration group, negative symptoms correlated with WCST nonperseverative errors, but for those in the long duration group the correlation was with perseverative errors.

CONCLUSION

We found a differential relationship between negative and cognitive symptoms in different stages of schizophrenia. Illness duration should be considered when studying the relationship between negative symptoms and cognition.

Consistency of symptomatic dimensions of schizophrenia over 20 years

Our goal was to analyze the consistency of the symptomatic dimensions of schizophrenia over the course of our 20-year prospective study. We investigated a sample of patients diagnosed with Diagnostic and Statistical Manual of Mental Disorders Third version (DSM III) schizophrenia and later re-diagnosed with Diagnostic and Statistical Manual of Mental Disorders Fourth version (DSM IV) at four intervals: three, seven, twelve and twenty years from their first hospitalization. The severity of symptoms was assessed using expanded version of Brief Psychiatric Rating Scale (BPRS - E). Exploratory factor analyses and then confirmatory factor analyses were conducted. A four-factor structure was found, with positive, negative, depressive and excitement factors. In the confirmatory factor analysis, the only symptomatic dimension confirmed at all follow-ups was the negative factor (emotional withdrawal, motor retardation, blunted affect and conceptual disorganization) as derived from the 20-year follow up in exploratory factor analysis. The positive syndrome derived from the three-year follow-up (hostility, suspiciousness, unusual thought content and hallucinations) was confirmed at the seven- and 20-year follow-ups. In the depressive syndrome the model from the 12-year follow-up (guilt, depression, suicidality, anxiety and somatic concern) was confirmed for the follow-ups after seven and 20 years. As regards the excitement syndrome, we confirmed the model from the three-year follow-up (motor hyperactivity, elated mood, conceptual disorganization, excitement) at the follow-ups at seven and 12 years.

Flat affect and social functioning: a 10 year follow-up study of first episode psychosis patients

BACKGROUND

Affective flattening has been described as enduring, but long term follow-up studies of first episode psychosis patients are lacking.

OBJECTIVE

The aim of this study was to follow the symptom development of flat affect (FA), over a 10 year follow-up period, with focus on prevalence, predictors and outcome factors including social functioning.

METHODS

Three-hundred-and-one patients with FEP were included at baseline, 186 participated in the 10 year follow-up. These were followed on PANSS item N1 (FA) from baseline through 5 follow-up assessments over 10 years. Patients were grouped as having never-present, improving, deteriorating, fluctuating or enduring FA. The groups were compared on baseline variables, variables at 10 year follow-up, and social functioning throughout the follow-up period.

RESULTS

Twenty nine percent never displayed FA, 66% had improving, deteriorating or fluctuating FA, while 5% of patients had enduring FA. Premorbid social function predicted enduring FA. The patients with enduring, fluctuating and deteriorating FA did poorer on all outcome variables, including remission and recovery rates. The enduring FA group did significantly poorer in social functioning over the 10 year period.

CONCLUSIONS

FA is expressed at some point of time in the majority of FEP patients in a 10 year follow-up period, and appears more fluctuant than expected from the relevant literature. FA is associated with poorer outcome after 10 years, and enduring FA to poorer social function at all points of assessment.

MR spectroscopy in schizophrenia

The purpose of this study is to review the MR spectroscopic literature regarding schizophrenia. However, as there are over 250 primary MRS articles and dozens of MRS review articles on the subject already, this study will take a different approach. First, the clinical features of schizophrenia will be described. The background neuroanatomy and biochemistry relevant to schizophrenia will be reviewed, as many readers of this journal are unlikely to be familiar with these fields. A current model of the abnormal neural circuitry in schizophrenia will be presented, and predictions extrapolated about relevant metabolite changes over time. Finally, the existing MRS literature will be reviewed in the context of our existing anatomical and chemical knowledge, and future MRS research directions will be elaborated.

Dissecting the Syndrome of Schizophrenia: Progress toward Clinically Useful Biomarkers

The search for clinically useful biomarkers has been one of the holy grails of schizophrenia research. This paper will outline the evolving notion of biomarkers and then outline outcomes from a variety of biomarkers discovery strategies. In particular, the impact of high-throughput screening technologies on biomarker discovery will be highlighted and how new or improved technologies may allow the discovery of either diagnostic biomarkers for schizophrenia or biomarkers that will be useful in determining appropriate treatments for people with the disorder. History tells those involved in biomarker research that the discovery and validation of useful biomarkers is a long process and current progress must always be viewed in that light. However, the approval of the first biomarker screen with some value in predicting responsiveness to antipsychotic drugs suggests that biomarkers can be identified and that these biomarkers that will be useful in diagnosing and treating people with schizophrenia.

Toward a terminology for functional recovery in schizophrenia: is functional remission a viable concept?

Recovery in schizophrenia is receiving increasing attention. Part of the increased focus is based on the recent working criteria for clinical remission in schizophrenia and the realization that many people with schizophrenia meet these criteria for remission. In this article, we consider whether functional disability can also be evaluated in a "remission" model. In so doing, we evaluate the concept of clinical remission, evaluate the possibility of remission of other generally stable features of schizophrenia such as negative symptoms, and make some heuristic terminological recommendations. We also propose a "level and breadth" model for the definition of functional remission and examine some of the alternate influences that could produce suboptimal everyday functioning, including effort, motivation, and societal barriers toward functional achievement.