Negative symptoms and cognitive deficits: what is the nature of their relationship?

Cognitive Effects of High-Frequency rTMS in Schizophrenia Patients With Predominant Negative Symptoms: Results From a Multicenter Randomized Sham-Controlled Trial

Cognitive impairments are one of the main contributors to disability and poor long-term outcome in schizophrenia. Proof-of-concept trials indicate that repetitive transcranial magnetic stimulation (rTMS) applied to the left dorsolateral prefrontal cortex (DLPFC) has the potential to improve cognitive functioning. We analyzed the effects of 10-Hz rTMS to the left DLPFC on cognitive deficits in schizophrenia in a large-scale and multicenter, sham-controlled study. A total of 156 schizophrenia patients with predominant negative symptoms were randomly assigned to a 3-week intervention (10-Hz rTMS, 15 sessions, 1000 stimuli per session) with either active or sham rTMS. The Rey Auditory Verbal Learning Test, Trail Making Test A and B, Wisconsin Card Sorting Test, Digit Span Test, and the Regensburg Word Fluency Test were administered before intervention and at day 21, 45, and 105 follow-up. From the test results, a neuropsychological composite score was computed. Both groups showed no differences in any of the outcome variables before and after intervention. Both groups improved markedly over time, but effect sizes indicate a numeric, but nonsignificant superiority of active rTMS in certain cognitive tests. Active 10-Hz rTMS applied to the left DLPFC for 3 weeks was not superior to sham rTMS in the improvement of various cognitive domains in schizophrenia patients with predominant negative symptoms. This is in contrast to previous preliminary proof-of-concept trials, but highlights the need for more multicenter randomized controlled trials in the field of noninvasive brain stimulation.

Confirmatory Factor Analysis and Differential Relationships of the Two Subdomains of Negative Symptoms in Chronically Ill Psychotic Patients

Research suggests a two factor structure for negative symptoms in patients with psychotic disorders: social amotivation (SA) and expressive deficits (ED). Applying this two-factor structure in clinical settings may provide valuable information with regard to outcomes and to target treatments. We aimed to investigate 1) whether the factor structure is also supported in chronically ill patients with a psychotic disorder and 2) what the relationship is between these factors and functioning (overall functioning and living situation), depressive symptoms and quality of life. 1157 Patients with a psychotic disorder and a duration of illness of 5 years or more were included in the analysis (data selected from the Pharmacotherapy Monitoring Outcome Survey; PHAMOUS). A confirmatory factor analysis was performed using items of the Positive and Negative Syndrome Scale that were previously identified to reflect negative symptoms (N1-4, N6, G5, G7, G13, G16). Subsequently, regression analysis was performed on outcomes. The results confirmed the distinction between SA (N2, N4, G16) and ED (N1, N3, N6, G5, G7, G13) in chronically ill patients. Both factors were related to worse overall functioning as measured with the Health of the Nation Outcome Scales, ED was uniquely associated with residential living status. Higher scores for SA were associated with more depressive symptoms and worse quality of life. Thus, SA is most strongly related to level of social-emotional functioning, while ED are more related to living situation and thereby are indicative of level of everyday functioning. This subdivision may be useful for research purposes and be a valuable additional tool in clinical practice and treatment development.

Motivation and Pleasure Scale-Self-Report (MAP-SR): Validation of the German version of a self-report measure for screening negative symptoms in schizophrenia

OBJECTIVES

Validated self-report instruments could provide a time efficient screening method for negative symptoms in people with schizophrenia. The aim of this study was to examine the psychometric properties of a German version of the Motivation and Pleasure Scale-Self-Report (MAP-SR) which is based on the Clinical Assessment Interview for Negative Symptoms (CAINS).

METHODS

In- and outpatients (N=50) with schizophrenia or schizoaffective disorder were assessed with standardized interviews and questionnaires on negative and positive symptoms and general psychopathology in schizophrenia, depression, and global functioning.

RESULTS

The German version of the MAP-SR showed high internal consistency. Convergent validity was supported by significant correlations between the MAP-SR with the experience sub-scale of the CAINS and the negative symptom sub-scale of the Positive and Negative Syndrome Scale. The MAP-SR also exhibited discriminant validity indicated by its non-significant correlations with positive symptoms and general psychopathology, which is in line with the findings for the original version of the MAP-SR. However, the MAP-SR correlated moderately with depression.

CONCLUSION

The German MAP-SR appears to be a valid and suitable diagnostic tool for the identification of negative symptoms in schizophrenia.

Social cognition as an RDoC domain

While the bulk of research into neural substrates of behavior and psychopathology has focused on cognitive, memory and executive functions, there has been a recent surge of interest in emotion processing and social cognition, manifested in designating Social Cognition as a major RDoC domain. We describe the origins of this field's influence on cognitive neuroscience and highlight the most salient findings leading to the characterization of the "social brain" and the establishments of parameters that quantify normative and aberrant behaviors. Such parameters of behavior and neurobiology are required for a potentially successful RDoC construct, especially if heritability is established, because of the need to link with genomic systems. We proceed to illustrate how a social cognition measure can be used within the RDoC framework by presenting a task of facial emotion identification. We show that performance is sensitive to normative individual differences related to age and sex and to deficits associated with schizophrenia and other psychotic disorders. Neuroimaging studies with this task demonstrate that it recruits limbic and frontal regulatory activation in healthy samples as well as abnormalities in psychiatric populations. Evidence for its heritability was documented in genomic family studies and in patients with the 22q11.2 deletion syndrome. Measures that meet such criteria can help build translational bridges between cellular molecular mechanisms and behavior that elucidate aberrations related to psychopathology. Such links will transcend current diagnostic classifications and ultimately lead to a mechanistically based diagnostic nomenclature. Establishing such bridges will provide the elements necessary for early detection and scientifically grounded intervention.

Verbal memory impairments in schizophrenia associated with cortical thinning

Verbal memory (VM) represents one of the most affected cognitive domains in schizophrenia. Multiple studies have shown that schizophrenia is associated with cortical abnormalities, but it remains unclear whether these are related to VM impairments. Considering the vast literature demonstrating the role of the frontal cortex, the parahippocampal cortex, and the hippocampus in VM, we examined the cortical thickness/volume of these regions. We used a categorical approach whereby 27 schizophrenia patients with 'moderate to severe' VM impairments were compared to 23 patients with 'low to mild' VM impairments and 23 healthy controls. A series of between-group vertex-wise GLM on cortical thickness were performed for specific regions of interest defining the parahippocampal gyrus and the frontal cortex. When compared to healthy controls, patients with 'moderate to severe' VM impairments revealed significantly thinner cortex in the left frontal lobe, and the parahippocampal gyri. When compared to patients with 'low to mild' VM impairments, patients with 'moderate to severe' VM impairments showed a trend of thinner cortex in similar regions. Virtually no differences were observed in the frontal area of patients with 'low to mild' VM impairments relative to controls. No significant group differences were observed in the hippocampus. Our results indicate that patients with greater VM impairments demonstrate significant cortical thinning in regions known to be important in VM performance. Treating VM deficits in schizophrenia could have a positive effect on the brain; thus, subgroups of patients with more severe VM deficits should be a prioritized target in the development of new cognitive treatments.

Correlation between neuropsychological and social cognition measures and symptom dimensions in schizophrenic patients

Neurocognitive and social cognition deficits have been largely reported in Schizophrenia (SKZ) but their association with psychopathology remains uncertain. Our purpose was to explore the relationship between symptom dimensions and neuropsychological performances. We enrolled 35 stabilized schizophrenic outpatients of the Department of Psychiatry of Policlinico Hospital, University of Milan, who completed psychiatric Rating Scales, the Brief Assessment of Cognition in Schizophrenia (BACS) and the Executive and Social Cognition Battery (ESCB). Disorganized dimension seems to have the most significant impact on cognition, being associated with performance in several BACS subtests (verbal memory, working memory, motor speed, symbol coding, Tower of London) and ESCB tasks (MET and Hotel task number of tasks attempted, number of broken MET rules, sum of deviations in Hotel Task). Positive dimension correlated with performance in verbal fluency, negative dimension with IOWA Test results, cognitive dimension with MET number of inefficiencies and Eyes test score. Impulsive-aggressive and depressive dimensions weakly correlated only with Faux Pas test. Our study supports the existence of a specific disorganized dimension in SKZ, separated from cognitive dimension evaluated through clinical instruments (e.g. PANSS), but capable of influencing cognitive abilities. Furthermore, it strengthens the validity of ecological tasks in evaluating cognition in SKZ.

Are negative symptoms really related to cognition in schizophrenia?

Previous studies have generally found a relationship between negative and cognitive symptoms in schizophrenia. The present study investigated the relationship between the 5 PANSS factors of a recent consensus model developed by NIMH researchers, and cognitive performance as assessed with the MATRICS Consensus Cognitive Battery (MCCB) in 80 patients with schizophrenia using correlation and regression analyses. The PANSS Cognitive factor showed a small to moderate significant association with MCCB Speed of processing, Working memory, Verbal learning, the Neurocognitive composite score, and the Overall composite score. Notably, however, no relationship was found between the PANSS Negative factor and any of the MCCB scores. The Positive, Excited and Depressed factors also did not show associations with the MCCB. These results highlight the need for refined assessment instruments and support the relative independence of cognition from other domains of psychopathology, including negative symptoms, in patients with schizophrenia.

The association of neurocognitive impairment with diminished expression and apathy in schizophrenia

Negative symptoms can be grouped into the two dimensions of diminished expression and apathy, which have been shown to be dissociable regarding external validators, such as functional outcome. Here, we investigated whether these two dimensions differentially relate to neurocognitive impairment in schizophrenia. 47 patients with schizophrenia or schizoaffective disorder and 33 healthy control participants were subjected to a neurocognitive test battery assessing multiple cognitive domains (processing speed, working memory, verbal fluency, verbal learning and memory, mental planning), which are integrated into a composite cognition score. Negative symptoms in patients were assessed using the Brief Negative Symptom Scale. We found that diminished expression significantly related to neurocognitive impairment, while severity of apathy symptoms was not directly associated with neurocognition. Other assessed clinical variables include chlorpromazine equivalents, positive symptoms, and depressive symptoms and did not influence the results. Our results are in line with a cognitive resource limitation model of diminished expression in schizophrenia and indicate that cognitive remediation therapy might be helpful to ameliorate expressive deficits.

In search of multimodal neuroimaging biomarkers of cognitive deficits in schizophrenia

BACKGROUND

The cognitive deficits of schizophrenia are largely resistant to current treatments and thus are a lifelong illness burden. The Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB) provides a reliable and valid assessment of cognition across major cognitive domains; however, the multimodal brain alterations specifically associated with MCCB in schizophrenia have not been examined.

METHODS

The interrelationships between MCCB and the abnormalities seen in three types of neuroimaging-derived maps-fractional amplitude of low-frequency fluctuations (fALFF) from resting-state functional magnetic resonance imaging (MRI), gray matter (GM) density from structural MRI, and fractional anisotropy from diffusion MRI-were investigated by using multiset canonical correlation analysis in data from 47 schizophrenia patients treated with antipsychotic medications and 50 age-matched healthy control subjects.

RESULTS

One multimodal component (canonical variant 8) was identified as both group differentiating and significantly correlated with the MCCB composite. It demonstrated 1) increased cognitive performance associated with higher fALFF (intensity of regional spontaneous brain activity) and higher GM volumes in thalamus, striatum, hippocampus, and the mid-occipital region, with co-occurring fractional anisotropy changes in superior longitudinal fascicules, anterior thalamic radiation, and forceps major; 2) higher fALFF but lower GM volume in dorsolateral prefrontal cortex related to worse cognition in schizophrenia; and 3) distinct domains of MCCB might exhibit dissociable multimodal signatures, e.g., increased fALFF in inferior parietal lobule particularly correlated with decreased social cognition. Medication dose did not relate to these findings in schizophrenia.

CONCLUSIONS

Our results suggest linked functional and structural deficits in distributed cortico-striato-thalamic circuits may be closely related to MCCB-measured cognitive impairments in schizophrenia.

Reduced auditory evoked gamma band response and cognitive processing deficits in first episode schizophrenia

OBJECTIVES

Gamma-band oscillations (e.g., the early auditory evoked gamma-band response, aeGBR) have been suggested to mediate cognitive and perceptual processes by driving the synchronization of local neuronal populations. Reduced aeGBR is a consistent finding in patients with schizophrenia and high-risk subjects, and has been proposed to represent an endophenotype for the illness. However, it is still unclear whether this reduction represents a deficit in sensory or cognitive processes, or a combination of the two. The present study investigated this question by manipulating the difficulty of an auditory reaction task in patients with first-episode schizophrenia and healthy controls.

METHODS

A 64-channel EEG was recorded in 23 patients with first-episode schizophrenia and 22 healthy controls during two conditions of an auditory reaction task: an easy condition that merely required low-level vigilance, and a difficult condition that placed significant demands on attention and working memory.

RESULTS

In contrast to healthy controls, patients failed to increase aeGBR power and phase-locking in the difficult condition. In patients, aeGBR power and phase-locking indices were associated with working memory deficits.

CONCLUSIONS

The observed results confirm the applicability of aeGBR disturbances as a stable endophenotype of schizophrenia, and suggest a cognitive, rather than sensory, deficit at their origin.

Effort-Based Decision-Making Paradigms for Clinical Trials in Schizophrenia: Part 2—External Validity and Correlates

Effort-based decision making has strong conceptual links to the motivational disturbances that define a key subdomain of negative symptoms. However, the extent to which effort-based decision-making performance relates to negative symptoms, and other clinical and functionally important variables has yet to be systematically investigated. In 94 clinically stable outpatients with schizophrenia, we examined the external validity of 5 effort-based paradigms, including the Effort Expenditure for Rewards, Balloon Effort, Grip Strength Effort, Deck Choice Effort, and Perceptual Effort tasks. These tasks covered 3 types of effort: physical, cognitive, and perceptual. Correlations between effort related performance and 6 classes of variables were examined, including: (1) negative symptoms, (2) clinically rated motivation and community role functioning, (3) self-reported motivational traits, (4) neurocognition, (5) other psychiatric symptoms and clinical/demographic characteristics, and (6) subjective valuation of monetary rewards. Effort paradigms showed small to medium relationships to clinical ratings of negative symptoms, motivation, and functioning, with the pattern more consistent for some measures than others. They also showed small to medium relations with neurocognitive functioning, but were generally unrelated to other psychiatric symptoms, self-reported traits, antipsychotic medications, side effects, and subjective valuation of money. There were relatively strong interrelationships among the effort measures. In conjunction with findings from a companion psychometric article, all the paradigms warrant further consideration and development, and 2 show the strongest potential for clinical trial use at this juncture.

The relationship between Positive and Negative Syndrome Scale (PANSS) schizophrenia severity scores and risk for hospitalization: an analysis of the CATIE Schizophrenia Trial

BACKGROUND

Little is known about the effect of treatment-related changes in Positive and Negative Syndrome Scale (PANSS) schizophrenia severity scores on the risk for subsequent hospitalization.

METHODS

We used limited-access data from the Clinical Antipsychotic Trials of Intervention Effectiveness Project Schizophrenia Trial (CATIE Sz) to evaluate the relationship between baseline and changes in PANSS clinical symptom scores and risks for subsequent psychiatric hospitalization.

RESULTS

Reductions in PANSS total scores during a three-month period were associated with a significantly lower risk for psychiatric hospitalization (OR, 0.78, 95% CI, 0.72 to 0.84, p<0.001 for 10 point reductions). Ten-point reductions in PANSS total score during three months reduced predicted number of psychiatric hospitalizations by 0.02 (95% CI, 0.012 to 0.027) and nights in the hospital by 0.24 (95% CI, 0.07 to 0.41). Maintenance of this reduction for a year is expected to reduce psychiatric hospitalizations by 0.10 (95% CI, 0.08 to 0.13) and nights hospitalized by 1.4 (95% CI, 0.9 to 1.9). A 10-point reduction in PANSS total score was associated with a savings in psychiatric hospitalization cost of $192 over three months and $1135 over a year.

CONCLUSIONS

Reductions in PANSS total scores significantly reduced risks for psychiatric hospitalizations, total number of psychiatric hospitalizations, total nights for psychiatric admissions, and the costs of these hospitalizations. These data highlight the benefits of symptom control on the direct costs of care in schizophrenia.

Motivation and Social Cognition in Patients with Schizophrenia

Social cognition, referring to one's ability to perceive and process social cues, is an important domain in schizophrenia. Numerous studies have demonstrated that patients with schizophrenia have poorer performance on tests assessing social cognition relative to healthy comparison participants. However, whether variables such as motivation are related to performance on these tests in patients with schizophrenia is unclear. One thousand three-hundred and seventy-eight patients with schizophrenia completed the Facial Emotion Discrimination Task as a measure of emotional processing, a key facet of social cognition. Level of motivation was also evaluated in these patients using a derived measure from the Quality of Life Scale. The relationship between motivation and task performance was examined using bivariate correlations and logistic regression modeling, controlling for the impact of age and overall severity of psychopathology, the latter evaluated using the Positive and Negative Syndrome Scale. Motivation was positively related to performance on the social cognition test, and this relationship remained significant after controlling for potential confounding variables such as age and illness severity. Social cognition was also related to functioning, and the relationship was mediated by level of motivation. The present study found a significant relationship between motivation and performance on a test of social cognition in a large sample of patients with schizophrenia. These findings suggest that amotivation undermines task performance, or alternatively that poor social cognitive ability impedes motivation. Future studies evaluating social cognition in patients with schizophrenia should concurrently assess for variables such as effort and motivation.

Determinants of different aspects of everyday outcome in schizophrenia: The roles of negative symptoms, cognition, and functional capacity

Cognition, negative symptoms, and depression are potential predictors of disability in schizophrenia. We present analyses of pooled data from four separate studies (all n>169; total n=821) that assessed differential aspects of disability and their potential determinants. We hypothesized that negative symptoms would predict social outcomes, but not vocational functioning or everyday activities and that cognition and functional capacity would predict vocational functioning and everyday activities but not social outcomes. The samples were rated by clinician informants for their everyday functioning in domains of social and vocational outcomes, and everyday activities, examined with assessments of cognition and functional capacity, rated clinically with the Positive and Negative Syndrome Scale (PANSS) and self-reporting depression. We computed a model that tested the hypotheses described above and compared it to a model that predicted that negative symptoms, depression, cognition, and functional capacity had equivalent influences on all aspects of everyday functioning. The former, specific relationship model fit the data adequately and we subsequently confirmed a similar fit within all four samples. Analyses of the relative goodness of fit suggested that this specific model fit the data better than the more general, equivalent influence predictor model. We suggest that treatments aimed at cognition may not affect social functioning as much as other aspects of disability, a finding consistent with earlier research on the treatment of cognitive deficits in schizophrenia, while negative symptoms predicted social functioning. These relationships are central features of schizophrenia and treatment efforts should be aimed accordingly.

Cognitive Performance associated to functional outcomes in stable outpatients with schizophrenia

Background–objective

Prevalence data of cognitive impairment in Schizophrenia based on large population samples are scarce. Our goal is to relate cognition and functional outcomes, and estimate prevalence of cognitive impairment in a large sample of schizophrenia outpatients treated with second-generation antipsychotics.

Method

A cross-sectional outpatient evaluation conducted during follow-up visits. Selection criteria included six-months stable treatment. The brief battery, EPICOG-SCH, covered four cognitive domains related to functional outcomes: working memory (WAIS-III-Letter-Number-Sequencing), executive function (Category Fluency Test; CFT), verbal memory (WMS-III-Logical-Memory), and information processing speed (Digit-Symbol-Coding and CFT). Clinical severity and functional impairment were assessed with CGI-SCH and WHO DAS-S. Impairment prevalence was calculated at ≤ 1.5 SD.

Results

Among patients recruited (n = 848) in 234 participating centers, 672 were under 6-month treatment. 61.5% (n = 413) reported cognitive impairment according to CGI-SCH Cognitive Subscale. Estimated prevalences were 85.9% (95% CI 85.6–86.2%) CFT-Fruits; 68.3% (95% CI 67.8–68.8%) CFT-Animals; 38.1% (95% CI 37.5–38.3%) Digit-Symbol-Coding; 24.8% (95% CI 24.1–25.5%) Verbal Memory-Units; 20.9% (95% CI 20.2–21.6%) Letter-Number Sequencing; 11.7% (95% CI 11.0–12.4%) Verbal Memory-Items. Negative and Depressive symptoms, Deficit Syndrome, and functional disability were related to poor performance. Functional disability was predicted by CGI-SCH-Overall severity (OR = 1.34635, p < 0.0001), CGI-SCH-Negative Symptoms (OR = 0.75540, p < 0.0001), working memory (Letter-Number-Sequencing) (OR = − 0.16442, p = 0.0004) and the time-course (OR = 0.05083, p = 0.0094), explaining 47% of the observed variability.

Conclusion

Most prevalent impairments were on executive function and processing speed domains; however, working memory showed the strongest relationship to functional disability. Monitoring cognitive function during follow up is critical to understand patient’s everyday functional capacity.

Kognitive Defizite bei Schizophren Erkrankten

Zusammenfassung. Theoretischer Hintergrund: Kognitive Funktionseinschränkungen sind zentrales Merkmal schizophrener Erkrankungen und werden entsprechend im Behandlungskonzept berücksichtigt. Kognitive Remediationsprogramme gelten als wirksam, Effektstärken als moderat. Trainingsvarianten werden zur Effektoptimierung erprobt. Fragestellung: Ist gezieltes Funktionstraining in neuroplastizitäts-orientiertem Lernkontext effektiver als breitgefächertes Behandlungsprogramm und werden Effekte durch das Erkrankungsstadium moduliert? Methode: Bei 59 chronisch und 31 ersthospitalisierten schizophren Erkrankten wurden kognitive Defizite über Testleistungen der MATRICS Consensus Cognitive Test Battery gegenüber 25 gesunder Kontrollpersonen erfasst. Testleistungen vor, nach 4-wöchiger Interventionsphase mit zwei spezifischen Trainings oder Standardbehandlung und 3-monatiger Katamnese prüften den Einfluss von Interventionstypus und Erkrankungsstadium auf Leistungsverbesserung. Ergebnisse: Sowohl chronische wie erstmals behandelte Patienten aller Behandlungsgruppen verbesserten sich signifikant über die Messzeitpunkte, obwohl Defizite relativ zu Kontrollen fortbestanden. Schlussfolgerungen: Spezifisches Training verbessert kognitive Funktionen nicht über Zeit/Remissionseffekte hinaus.

Impairments of event-related magnetic fields in schizophrenia patients with predominant negative symptoms

Recently there is a growing understanding that patients suffering from negative symptoms of schizophrenia represent a distinct patient population. However, despite the abundance of EEG studies characterizing schizophrenia patients in general, only a handful of studies have focused on the electrophysiological correlates of negative symptoms. The current study examined whether the impairments in event-related magnetic fields (ERFs) commonly reported in heterogeneous groups of patients with mixed positive and negative symptoms also occur in patients with predominantly negative symptoms, and investigated their correlation to clinical symptoms and cognitive deficits. Twenty schizophrenia patients suffering from predominant negative symptoms and 25 healthy subjects underwent neuropsychological and electromagnetic assessments. ERFs were recorded during a three-stimuli novelty oddball and a sensory gating paradigm, and M50, P300m and Novelty-P3m components were investigated. Patients displayed impaired M50 ratios, reduced left P300m and frontal Novelty-P3m amplitudes. These electromagnetic measures correlated significantly with the severity of negative symptoms (SANS scale). The electrophysiological abnormalities which have been proposed as candidate biomarkers for schizophrenia are also manifested in patients with predominantly negative symptoms.

Negative symptoms and functioning during the first year after a recent onset of schizophrenia and 8 years later

BACKGROUND

Understanding the longitudinal course of negative symptoms, especially in relationship to functioning, in the early phase of schizophrenia is crucial to developing intervention approaches. The course of negative symptoms and daily functioning was examined over a 1-year period following a recent onset of schizophrenia and at an 8-year follow-up point.

METHODS

The study included 149 recent-onset schizophrenia patients who had a mean age of 23.7 (SD=4.4)years and mean education of 12.9 (SD=2.2)years. Negative symptom (BPRS and SANS) and functional outcome (SCORS) assessments were conducted frequently by trained raters.

RESULTS

After antipsychotic medication stabilization, negative symptoms during the first outpatient year were moderately stable (BPRS ICC=0.64 and SANS ICC=0.66). Despite this overall moderate stability, 24% of patients experienced at least one period of negative symptoms exacerbation. Furthermore, entry level of negative symptoms was significantly associated with poor social functioning (r=-.34, p<.01) and work/school functioning (r=-.25, p<.05) at 12months, and with negative symptoms at the 8-year follow-up (r=.29, p<.05).

DISCUSSION

Early negative symptoms are fairly stable during the first outpatient year, are predictors of daily functioning at 12months, and predict negative symptoms 8years later. Despite the high levels of stability, negative symptoms did fluctuate in a subsample of patients. These findings suggest that negative symptoms may be an important early course target for intervention aimed at promoting recovery.

Neurodevelopmental origin of cognitive impairment in schizophrenia

Cognitive impairment is a common feature of schizophrenia; however, its origin remains controversial. Neurodevelopmental abnormalities clearly play a role in pre-morbid cognitive dysfunction in schizophrenia, yet many authors believe that schizophrenia is characterized by illness-related cognitive decline before and after onset of the psychosis that can be the result of neurodegenerative changes. The main reasons behinds such arguments include, first, the evidence showing that effect sizes of the cognitive deficits in subjects who develop adult schizophrenia gradually increase in the first two decades of life and, second, the fact that there is functional decline in many patients with schizophrenia over the years. In this Editorial, I argue that current evidence suggests that illness-related cognitive impairment is neurodevelopmental in origin and characterized by slower gain (developmental lag) but not cognitive decline continuing throughout the first two decades of life. I introduce a model suggesting that neurodevelopmental abnormality can in fact explain the course of cognitive dysfunction and variations in the trajectory of functional decline throughout the life in individuals with schizophrenia. In this model, the severity of underlying neurodevelopmental abnormality determines the age that cognitive deficits first become apparent and contributes to the cognitive reserve of the individual. Interaction of neurodevelopmental abnormality with clinical symptoms, especially negative symptoms and aging, vascular changes, psychological and iatrogenic factors contributes to the heterogeneity of the functional trajectory observed in this disorder.

Validation of the German version of the Clinical Assessment Interview for Negative Symptoms (CAINS)

Validated assessment instruments could contribute to a better understanding and assessment of negative symptoms and advance treatment research. The aim of this study was to examine the psychometric properties of a German version of the Clinical Assessment Interview for Negative Symptoms (CAINS). In- and outpatients (N=53) with schizophrenia or schizoaffective disorder were assessed with standardized interviews and questionnaires on negative and positive symptoms and general psychopathology in schizophrenia, depression, the ability to experience anticipatory and consummatory pleasure, and global functioning. The results indicated good psychometric properties, high internal consistency and promising inter-rater agreement for the German version of the CAINS. The two-factor solution of the original version of the CAINS was confirmed, indicating good construct validity. Convergent validity was supported by significant correlations between the CAINS subscales with the negative symptom scale of the Positive and Negative Syndrome Scale, and with consummatory pleasure. The CAINS also exhibited discriminant validity indicated by its non-significant correlations with positive symptoms, general psychopathology and depression that are in line with the findings for the original version of the CAINS. In addition, the CAINS correlated moderately with global functioning. The German version of the CAINS appears to be a valid and suitable diagnostic tool for measuring negative symptoms in schizophrenia.

Treatment resistance and other complicating factors in the management of schizophrenia

Treatment resistance, along with its sibling partial response, remains a common phenomenon in schizophrenia, complicating the disability burden inherent in the disease. Antipsychotic medications are the mainstay of treatment, and treatment resistance has mainly been defined in terms of poor response to antipsychotic medication. At the same time, clozapine, the most effective antipsychotic, remains underutilized at the expense of exposing patients to polypharmacy. We review known causes of disability in schizophrenia, how they impact various areas of everyday functioning, and discuss potential treatment options including but not limited to pharmacological approaches aimed at maximizing treatment response and reducing treatment resistance.

POSITIVE AND NEGATIVE SUBCLINICAL SYMPTOMS AND MCCB PERFORMANCE IN NON-PSYCHIATRIC CONTROLS

Considerable data support the phenomenological and temporal continuity between subclinical psychosis and psychotic disorders. In recent years, neurocognitive deficits have increasingly been recognized as a core feature of psychotic illness but there are few data seeking to elucidate the relationship between subclinical psychosis and neurocogntive deficits in non-clinical samples. The goal of the present study was to examine the relationship between subclinical positive and negative symptoms, as measured by the Community Assessment of Psychic Experiences (CAPE) and performance on the MATRICS Consensus Cognitive Battery (MCCB) in a large (n = 303) and demographically diverse non-clinical sample. We found that compared to participants with low levels of subclinical positive symptoms, participants with high levels of subclinical positive symptoms performed significantly better in the domains of working memory (p < .001), verbal learning (p = .007) and visual learning (p = .014). Although comparison of participants with high and low levels of subclinical negative symptoms revealed no differences in MCCB performance, we found that individuals with high levels of subclinical negative symptoms performed significantly better on a measure of estimated IQ (WRAT-3 Reading subtest; p = .02) than those with low levels of subclinical negative symptoms. These results are at odds with prior reports that have generally shown a negative relationship between neurocognitive functioning and severity of subclinical psychotic symptoms, and suggest some potential discontinuities between clinically significant psychotic symptoms and sub-syndromal manifestations of psychosis.

The relationship of neurocognition and negative symptoms to social and role functioning over time in individuals at clinical high risk in the first phase of the North American Prodrome Longitudinal Study

OBJECTIVES

Impaired social, role, and neurocognitive functioning are preillness characteristics of people who later develop psychosis. In people with schizophrenia, neurocognition and negative symptoms are associated with functional impairment. We examined the relative contributions of neurocognition and symptoms to social and role functioning over time in clinically high-risk (CHR) individuals and determined if negative symptoms mediated the influence of cognition on functioning.

METHODS

Social, role, and neurocognitive functioning and positive, negative, and disorganized symptoms were assessed in 167 individuals at CHR for psychosis in the North American Prodrome Longitudinal Study Phase 1 (NAPLS-1), of whom 96 were reassessed at 12 months.

RESULTS

Regression analyses indicated that negative symptoms accounted for unique variance in social and role functioning at baseline and follow-up. Composite neurocognition accounted for unique, but modest, variance in social and role functioning at baseline and in role functioning at follow-up. Negative symptoms mediated the relationship between composite neurocognition and social and role functioning across time points. In exploratory analyses, individual tests (IQ estimate, Digit Symbol/Coding, verbal memory) selectively accounted for social and role functioning at baseline and follow-up after accounting for symptoms. When negative symptom items with content overlapping with social and role functioning measures were removed, the relationship between neurocognition and social and role functioning was strengthened.

CONCLUSION

The modest overlap among neurocognition, negative symptoms, and social and role functioning indicates that these domains make substantially separate contributions to CHR individuals.

Motivational and neurocognitive deficits are central to the prediction of longitudinal functional outcome in schizophrenia

OBJECTIVE

Functional impairment is characteristic of most individuals with schizophrenia; however, the key variables that undermine community functioning are not well understood. This study evaluated the association between selected clinical variables and one-year longitudinal functional outcomes in patients with schizophrenia.

METHOD

The sample included 754 patients with schizophrenia who completed both baseline and one-year follow-up visits in the CATIE study. Patients were evaluated with a comprehensive battery of assessments capturing symptom severity and cognitive performance among other variables. The primary outcome variable was functional status one-year postbaseline measured using the Heinrichs-Carpenter Quality of Life Scale.

RESULTS

Factor analysis of negative symptom items revealed two factors reflecting diminished expression and amotivation. Multivariate regression modeling revealed several significant independent predictors of longitudinal functioning scores. The strongest predictors were baseline amotivation and neurocognition. Both amotivation and neurocognition also had independent predictive value for each of the domains of functioning assessed (e.g., vocational).

CONCLUSION

Both motivational and neurocognitive deficits independently contribute to longitudinal functional outcomes assessed 1 year later among patients with schizophrenia. Both of these domains of psychopathology impede functional recovery; hence, it follows that treatments ameliorating each of these symptoms should promote community functioning among individuals with schizophrenia.

The Concept of Schizophrenia: From Unity to Diversity

After over 100 years of research without clarifying the aetiology of schizophrenia, a look at the current state of knowledge in epidemiology, genetics, precursors, psychopathology, and outcome seems worthwhile. The disease concept, created by Kraepelin and modified by Bleuler, has a varied history. Today, schizophrenia is considered a polygenic disorder with onset in early adulthood, characterized by irregular psychotic episodes and functional impairment, but incident cases occur at all ages with marked differences in symptoms and social outcome. Men’s and women’s lifetime risk is nearly the same. At young age, women fall ill a few years later and less severely than men, men more rarely and less severely later in life. The underlying protective effect of oestrogen is antagonized by genetic load. The illness course is heterogeneous and depressive mood the most frequent symptom. Depression and schizophrenia are functionally associated, and affective and nonaffective psychoses do not split neatly. Most social consequences occur at the prodromal stage. Neither schizophrenia as such nor its main symptom dimensions regularly show pronounced deterioration over time. Schizophrenia is neither a residual state of a neurodevelopmental disorder nor a progressing neurodegenerative process. It reflects multifactorial CNS instability, which leads to cognitive deficits and symptom exacerbations.

Cognitive effects of atypical antipsychotic drugs in first-episode drug-naïve schizophrenic patients

Cognitive impairment is a core feature of schizophrenia. The present randomized open study enrolled antipsychotic-naïve patients who were experiencing their first episode of schizophrenia. After baseline neurocognitive tests and clinical assessment, subjects were randomly assigned to olanzapine, risperidone and aripiprazole treatment groups. A battery of neurocognitive tests showed that risperidone produced cognitive benefits in all five cognitive domains, including verbal learning and memory, visual learning and memory, working memory, processing speed, and selective attention; olanzapine improved processing speed and selective attention; and aripiprazole improved visual learning and memory, and working memory. However, the three atypical antipsychotic drugs failed to reveal any significant differences in the composite cognitive scores at the study endpoint. In addition, the three drugs all significantly improved clinical measures without significant differences between the drugs after 6 months. These results suggest that the atypical antipsychotics, olanzapine, risperidone and aripiprazole may improve specific cognitive domains with similar global clinical efficacy. In clinical practice, it may be feasible to choose corresponding atypical antipsychotics according to impaired cognitive domains.

Openness to experience, intellect, schizotypal personality disorder, and psychoticism: resolving the controversy

Section III of DSM-5 includes an alternative model for personality disorders comprising five higher-order pathological personality traits, four of which resemble domains from the Big Five/Five-Factor Model of Personality (FFM). There has, however, been considerable debate regarding the association of FFM Openness-to-Experience/Intellect (OE/I) with DSM-5 Psychoticism and Schizotypal Personality Disorder (STPD). The authors identify several limitations in the literature, including inattention to (a) differences in the conceptualization of OE/I in the questionnaire and lexical traditions and (b) the symptom heterogeneity of STPD. They then address these limitations in two large patient samples. The results suggest that OE/I per se is weakly associated with Psychoticism and STPD symptoms. However, unique variance specific to the different conceptualizations of OE/I demonstrates much stronger associations, often in opposing directions. These results clarify the debate and the seemingly discrepant views that OE/I is unrelated to Psychoticism and contains variance relevant to Psychoticism.

The role of dysfunctional attitudes in models of negative symptoms and functioning in schizophrenia

Neurocognitive impairment is associated with negative symptoms and poor real world functioning in schizophrenia. Dysfunctional attitudes (e.g., "If I fail partly, it is as bad as being a complete failure") have been found to mediate these relationships between neurocognition and negative symptoms and functioning. In this study, these relationships were examined in 179 participants with schizophrenia or schizoaffective disorder using structural equation modeling. Defeatist attitudes were found to mediate the relationship between neurocognition and negative symptoms but not the relationships between neurocognition and performance-based or self-reported functioning. A full model with the best fit showed mediation between neurocognition and self-reported functioning through two different pathways: One from neurocognition to functional skill capacity to real-world functioning, and a second from neurocognition to defeatist attitudes to negative symptoms to real-world functioning. These results may implicate skill deficits and defeatist attitudes as a separate treatment targets for negative symptoms and functioning in schizophrenia.

Psychosocial support and cognitive deficits in adults with schizophrenia

BACKGROUND

In recent decades there has been an increasing interest in cognitive deficits in schizophrenia. However, only a few studies have examined the impact of psychosocial support on the prevention of cognitive deterioration in patients who suffer from schizophrenia.

AIM

The aims of the present study are: (1) to confirm the presence of cognitive deficits among patients with schizophrenia; (2) to explore any correlations between such deficits and a range of clinical and/or demographic characteristics of the patients; and (3) to investigate any association between cognitive deficits and psychosocial support.

METHOD

A total of 118 patients with schizophrenia (the patient group) and 102 healthy volunteers (the control group) had a cognitive assessment using a battery of neuropsychological tests. The patients were allocated to one of the following groups: (1) patients under routine outpatient follow-up; or (2) patients receiving or having recently received intensive psychosocial support, in addition to follow-up. This included daily participation in vocational and recreational activities provided by dedicated mental health day centers. The findings of the neuropsychological testing of individuals in all groups were compared, after controlling for clinical or demographic factors.

RESULTS

The scores in the neuropsychological tests were lower overall in the patients group compared to healthy volunteers. Within the patients group, those receiving/having received psychosocial support had higher scores compared to those on routine follow-up alone. There were no significant differences between patients currently receiving psychosocial support and those having received it in the past. Lower education, age and illness duration (but not severity of positive or negative symptoms) were factors associated with lower test scores.

CONCLUSIONS

The study provides some evidence that psychosocial support may be beneficial for the cognitive functioning of patients with schizophrenia and this benefit may be a lasting one.

Physical activity level and medial temporal health in youth at ultra high-risk for psychosis

A growing body of evidence suggests that moderate to vigorous activity levels can affect quality of life, cognition, and brain structure in patients diagnosed with schizophrenia. However, physical activity has not been systematically studied during the period immediately preceding the onset of psychosis. Given reports of exercise-based neurogenesis in schizophrenia, understanding naturalistic physical activity levels in the prodrome may provide valuable information for early intervention efforts. The present study examined 29 ultra high-risk (UHR) and 27 matched controls to determine relationships between physical activity level, brain structure (hippocampus and parahippocampal gyrus), and symptoms. Participants were assessed with actigraphy for a 5-day period, MRI, and structured clinical interviews. UHR participants showed a greater percentage of time in sedentary behavior while healthy controls spent more time engaged in light to vigorous activity. There was a strong trend to suggest the UHR group showed less total physical activity. The UHR group exhibited smaller medial temporal volumes when compared with healthy controls. Total level of physical activity in the UHR group was moderately correlated with parahippocampal gyri bilaterally (right: r = .44, left: r = .55) and with occupational functioning (r = -.36; of negative symptom domain), but not positive symptomatology. Results suggest that inactivity is associated with medial temporal lobe health. Future studies are needed to determine if symptoms are driving inactivity, which in turn may be affecting the health of the parahippocampal structure and progression of illness. Although causality cannot be determined from the present design, these findings hold important implications for etiological conceptions and suggest promise for an experimental trial.

The role of low cognitive effort and negative symptoms in neuropsychological impairment in schizophrenia

OBJECTIVE

Two experiments were conducted to examine whether insufficient effort, negative symptoms (e.g., avolition, anhedonia), and psychological variables (e.g., anhedonia and perception of low cognitive resources) predict generalized neurocognitive impairment in individuals with schizophrenia (SZ).

METHOD

In Experiment 1, participants included 97 individuals with SZ and 63 healthy controls (CN) who completed the Victoria Symptom Validity Test (VSVT), the MATRICS Consensus Cognitive Battery (MCCB), and self-report anhedonia questionnaires. In Experiment 2, participants included 46 individuals with SZ and 33 CN who completed Green's Word Memory Test (WMT), the MCCB, and self-reports of anhedonia, defeatist performance beliefs, and negative expectancy appraisals.

RESULTS

RESULTS indicated that a low proportion of individuals with SZ failed effort testing (1.0% Experiment 1; 15.2% Experiment 2); however, global neurocognitive impairment was significantly predicted by low effort and negative symptoms.

CONCLUSIONS

Findings indicate that low effort does not threaten the validity of neuropsychological test results in the majority of individuals with schizophrenia; however, effort testing may be useful in SZ patients with severe negative symptoms who may be more likely to put forth insufficient effort due to motivational problems. Although the base rate of failure is relatively low, it may be beneficial to screen for insufficient effort in SZ and exclude individuals who fail effort testing from pharmacological or cognitive remediation trials.

Treatment response heterogeneity in the predominant negative symptoms of schizophrenia: analysis of amisulpride vs placebo in three clinical trials

BACKGROUND

The extent of heterogeneity in response to the psychopharmacological treatment of negative symptoms is unknown.

AIMS

To examine the extent of heterogeneity in response to the treatment of predominantly negative symptoms of schizophrenia.

METHOD

Data were analyzed from three clinical trials that compared placebo or amisulpride for up to 60days. Trial participants had predominantly negative symptoms of schizophrenia (n=485). Heterogeneity of percentage reduction on the Scale for the Assessment of Negative Symptoms (SANS) was examined with trajectory-group based modeling followed by descriptive statistics and the prediction of trajectory group membership with logistic regression modeling. Analyses were repeated separately for the placebo and amisulpride groups.

RESULTS

Trajectory group-based modeling identified groups of non- (n=297, 61.2%), gradual-moderate (n=135, 27.8%) and rapid- (n=53, 10.9%) responders. At baseline compared to non-responders, rapid-responders had consistently significantly (p<.05) higher SANS total and subscale scores. Percent SANS improvement at endpoint was greatest for the rapid-responders group, a finding that replicated stratifying by placebo and amisulpride treatment groups. Similarly, in the total sample and stratifying by placebo and amisulpride groups, dropout was not significantly associated with trajectory group membership.

CONCLUSIONS

Trajectories of treatment response to the psychopharmacological medication of the negative symptoms of schizophrenia demonstrate substantial heterogeneity. Approximately half of the patients included in our analysis showed little improvement, and the most severely ill at baseline responded the most.

It is all in the factors: effects of cognitive remediation on symptom dimensions

BACKGROUND

Cognitive remediation (CR) aims primarily to improve cognition and functional outcomes. However, a limited number of studies reported a positive effect on symptoms. This limited effect may be because the symptom clusters considered are too broad and heterogeneous. This study explores, for the first time, the effect of CR on five empirically defined symptom dimensions of schizophrenia.

METHOD

Participants were patients with schizophrenia taking part in a randomised controlled trial comparing CR plus treatment as usual (CR, N=43) to treatment as usual (TAU, N=42). All participants were assessed at baseline and 14-weeks (i.e. at the conclusion of treatment for the CR group) with the Positive and Negative Symptoms Scale (PANSS). Five symptom dimensions were derived from the PANSS scores: Positive (POS), Negative (NEG), Disorganised (DIS), Excited (EXC) and Emotional Distressed (EMD).

RESULTS

After CR, the therapy group had a significant reduction in DIS and NEG symptom dimensions compared to the TAU group. The traditional PANSS factors showed no effect of CR on symptoms.

CONCLUSION

CR can have not only a positive effect on disorganisation but also on negative symptoms. Using detailed symptom dimensions can characterise more accurately the effect of CR on symptom of schizophrenia.

Negative symptoms of schizophrenia: clinical features, relevance to real world functioning and specificity versus other CNS disorders

Negative symptoms have long been recognized as a central feature of the phenomenology of schizophrenia, dating back to the early descriptions by Kraepelin and Bleuler. Over the ensuing century, there have been important clarifications and reconceptualizations regarding the phenomenology of negative symptoms in schizophrenia. This review explores these developments, including the delineation of two underlying subdomains of negative symptoms - amotivation (i.e., avolition/apathy and asociality) and diminished expression (i.e., poverty of speech and affective flattening). Further, advances in our understanding of specific motivational and hedonic deficits seen in schizophrenia are explored. The findings that negative symptoms stand apart from depressive and cognitive symptoms in schizophrenia are also discussed. In terms of the predictors of functional outcomes in schizophrenia, we explore both the direct role of negative symptoms in this regard, as well as their indirect role through cognition. We then broaden our examination of negative symptoms to related disorders across the schizophrenia spectrum, as well as to other neuropsychiatric illnesses, where negative symptoms have been increasingly recognized. We explore the differential characteristics of negative symptoms across these illnesses, and their relevance to functional outcomes. This transdiagnostic presence and relevance of negative symptoms highlights the need for continued exploration of their phenomenology and neurobiology as we move to develop effective interventions to address these debilitating symptoms and improve functional outcomes.

Negative symptoms of schizophrenia: clinical characteristics, pathophysiological substrates, experimental models and prospects for improved treatment

Schizophrenia is a complex and multifactorial disorder generally diagnosed in young adults at the time of the first psychotic episode of delusions and hallucinations. These positive symptoms can be controlled in most patients by currently-available antipsychotics. Conversely, they are poorly effective against concomitant neurocognitive dysfunction, deficits in social cognition and negative symptoms (NS), which strongly contribute to poor functional outcome. The precise notion of NS has evolved over the past century, with recent studies - underpinned by novel rating methods - suggesting two major sub-domains: "decreased emotional expression", incorporating blunted affect and poverty of speech, and "avolition", which embraces amotivation, asociality and "anhedonia" (inability to anticipate pleasure). Recent studies implicate a dysfunction of frontocortico-temporal networks in the aetiology of NS, together with a disruption of cortico-striatal circuits, though other structures are also involved, like the insular and parietal cortices, amygdala and thalamus. At the cellular level, a disruption of GABAergic-glutamatergic balance, dopaminergic signalling and, possibly, oxytocinergic and cannibinoidergic transmission may be involved. Several agents are currently under clinical investigation for the potentially improved control of NS, including oxytocin itself, N-Methyl-d-Aspartate receptor modulators and minocycline. Further, magnetic-electrical "stimulation" strategies to recruit cortical circuits and "cognitive-behavioural-psychosocial" therapies likewise hold promise. To acquire novel insights into the causes and treatment of NS, experimental study is crucial, and opportunities are emerging for improved genetic, pharmacological and developmental modelling, together with more refined readouts related to deficits in reward, sociality and "expression". The present article comprises an integrative overview of the above issues as a platform for this Special Issue of European Neuropsychopharmacology in which five clinical and five preclinical articles treat individual themes in greater detail. This Volume provides, then, a framework for progress in the understanding - and ultimately control - of the debilitating NS of schizophrenia.

Social interaction and social withdrawal in rodents as readouts for investigating the negative symptoms of schizophrenia

Negative symptoms (e.g., asociality and anhedonia) are a distinct symptomatic domain that has been found to significantly affect the quality of life in patients diagnosed with schizophrenia. Additionally, the primary negative symptom of asociality (i.e., withdrawal from social contact that derives from indifference or lack of desire to have social contact) is a major contributor to poor psychosocial functioning and has been found to play an important role in the course of the disorder. Nonetheless, the pathophysiology underlying these symptoms is unknown and currently available treatment options (e.g., antipsychotics and cognitive-behavioral therapy) fail to reliably produce efficacious benefits. Utilizing rodent paradigms that measure social behaviors (e.g., social withdrawal) to elucidate the neurobiological substrates that underlie social dysfunction and to identify novel therapeutic targets may be highly informative and useful to understand more about the negative symptoms of schizophrenia. Accordingly, the purpose of this review is to provide an overview of the behavioral tasks for assessing social functioning that may be translationally relevant for investigating negative symptoms associated with schizophrenia.

Impaired musical ability in people with schizophrenia

BACKGROUND

Assessment of the musical ability of people with schizophrenia has attracted little interest despite the diverse and substantive findings of impairments in sound perception and processing and the therapeutic effect of music in people with the illness. The present study investigated the musical ability of people with schizophrenia and the association with psychiatric symptoms and cognition.

METHODS

We recruited patients with chronic schizophrenia and healthy controls for participation in our study. To measure musical ability and cognitive function, we used the Montreal Battery of Evaluation of Amusia (MBEA) and the Brief Assessment of Cognition in Schizophrenia (BACS). We carried out a mediation analysis to investigate a possible pathway to a deficit in musical ability.

RESULTS

We enrolled 50 patients and 58 controls in the study. The MBEA global score in patients with schizophrenia was significantly lower than that in controls (p < 0.001), and was strongly associated with both the composite cognitive function score (r = 0.645, p < 0.001) and the negative symptom score (r = -0.504, p < 0.001). Further analyses revealed direct and indirect effects of negative symptoms on musical ability. The indirect effects were mediated through cognitive impairment.

LIMITATIONS

The relatively small sample size did not permit full evaluation of the possible effects of age, sex, education, medication and cultural influences on the results.

CONCLUSION

Examining the associations between musical deficits, negative symptoms and cognitive imapirment in patients with schizophrenia may identify shared biological mechanisms.

Effects of raloxifene on cognition in postmenopausal women with schizophrenia: a double-blind, randomized, placebo-controlled trial

Studies of estrogen therapy in postmenopausal women provide evidence of an effect of sex hormones on cognitive function. Estrogen has demonstrated some utility in the prevention of normal, age-related decline in cognitive functions, especially in memory. The potential therapeutic utility of estrogens in schizophrenia is increasingly being recognized. Raloxifene, a selective estrogen receptor modulator (SERM), appears to act similarly to conjugated estrogens on dopamine and serotonin brain systems, and may be a better option since it lacks the possible negative effects of estrogen on breast and uterine tissue. We assessed the utility of raloxifene as an adjuvant treatment for cognitive symptoms in postmenopausal women with schizophrenia in a 12-week, double-blind, randomized, placebo-controlled study. Patients were recruited from both the inpatient and outpatient departments. Thirty-three postmenopausal women with schizophrenia (DSM-IV) were randomized to receive either adjuvant raloxifene (16 women) or adjuvant placebo (17 women) for three months. The main outcome measures were: Memory, attention and executive functions. Assessment was conducted at baseline and week 12. The total sample is homogenous with respect to: age, years of schooling, illness duration, baseline symptomatology and pharmacological treatment. The addition of raloxifene (60 mg) to regular antipsychotic treatment showed: we found significant differences in some aspects of memory and executive function in patients treated with raloxifene. This improvement does not correlate with clinical improvement. The use of raloxifene as an adjuvant treatment in postmenopausal women with schizophrenia seems to be useful in improving cognitive symptoms.

Residual negative symptoms differentiate cognitive performance in clinically stable patients with schizophrenia and bipolar disorder

Cognitive deficits in various domains have been shown in patients with bipolar disorder and schizophrenia. The purpose of the present study was to examine if residual psychopathology explained the difference in cognitive function between clinically stable patients with schizophrenia and bipolar disorder. We compared the performance on tests of attention, visual and verbal memory, and executive function of 25 patients with schizophrenia in remission and 25 euthymic bipolar disorder patients with that of 25 healthy controls. Mediation analysis was used to see if residual psychopathology could explain the difference in cognitive function between the patient groups. Both patient groups performed significantly worse than healthy controls on most cognitive tests. Patients with bipolar disorder displayed cognitive deficits that were milder but qualitatively similar to those of patients with schizophrenia. Residual negative symptoms mediated the difference in performance on cognitive tests between the two groups. Neither residual general psychotic symptoms nor greater antipsychotic doses explained this relationship. The shared variance explained by the residual negative and cognitive deficits that the difference between patient groups may be explained by greater frontal cortical neurophysiological deficits in patients with schizophrenia, compared to bipolar disorder. Further longitudinal work may provide insight into pathophysiological mechanisms that underlie these deficits.

Trajectories of symptom dimensions in short-term response to antipsychotic treatment in patients with a first episode of non-affective psychosis

BACKGROUND

Trajectory patterns of positive, disorganized and negative dimension symptoms during antipsychotic treatment in drug-naive patients with first-episode psychosis have yet to be examined by using naturalistic data.

METHOD

This pragmatic clinical trial randomized 161 drug-naive patients with a first episode of psychosis to olanzapine, risperidone or haloperidol. Patients were assessed with the Scale for the Assessment of Negative Symptoms (SANS) and Positive Symptoms (SAPS) at baseline and at the end of weeks 1, 2, 3, 4 and 6 of antipsychotic treatment. Censored normal models of response trajectories were developed with three dimensions of the SAPS-SANS scores (positive, disorganized and negative) in order to identify the different response trajectories. Diagnosis, cannabis use, duration of untreated psychosis (DUP), smoking and antipsychotic class were examined as possible predictive variables.

RESULTS

Patients were classified in five groups according to the positive dimension, three groups according to the disorganized dimension and five groups according to the negative dimension. Longer DUPs and cannabis use were associated with higher scores and poorer responses in the positive dimension. Cannabis use was associated with higher scores and poorer responses in the disorganized dimension. Only schizophrenia diagnosis was associated with higher scores and poorer responses in the negative dimension.

CONCLUSIONS

Our results illustrate the heterogeneity of short-term response to antipsychotics in patients with a first episode of psychosis and highlight markedly different patterns of response in the positive, disorganized and negative dimensions. DUP, cannabis use and diagnosis appeared to have a prognostic value in predicting treatment response with different implications for each dimension.

Relationship between diminished expression and cognitive impairment in first-episode schizophrenia: a prospective three-year follow-up study

BACKGROUND

Diminished expression (DE) is a core sub-domain of negative symptoms construct in schizophrenia. There is limited, yet inconsistent data regarding DE and its associations with cognition, particularly in the early illness course. This study aimed to examine cross-sectional and longitudinal relationships of DE with cognitive functions in first-episode schizophrenia utilizing a prospective design.

METHOD

Ninety-three Hong Kong Chinese aged 18 to 55 years presenting with first-episode schizophrenia-spectrum disorder were studied. Severity of DE was measured as sum of individual item scores indicative of affect flattening and alogia. Symptom evaluation was conducted at intake, after clinical stabilization of first psychotic episode, at 12, 24 and 36 months. Cognitive functions were evaluated at clinical stabilization, 12, 24 and 36 months.

RESULTS

DE was significantly correlated with various cognitive functions in successive follow-up assessments. Regression analyses adjusting confounding effects of sex, pre-morbid adjustment, duration of untreated psychosis and chlorpromazine equivalents showed that DE was associated with performance on verbal fluency at 12 (p<0.01) and 24 months (p<0.05), visual reproduction at 24 (p<0.05) and 36 months (p<0.01), logical memory at 36 months (p<0.05) and Modified Wisconsin Card Sorting test at 24 (p<0.05) and 36 months (p<0.05). Neither cross-lagged associations between DE and cognition nor significant correlations between changes in these two domains over three years were observed.

CONCLUSIONS

DE and cognitive functions were correlated concurrently but no longitudinal associations between these two domains could be demonstrated. Our findings indicated that DE and cognitive impairment represented relatively independent domains of the illness with potentially distinctive therapeutic implications.

Predominant negative symptoms in 22q11.2 deletion syndrome and their associations with cognitive functioning and functional outcome

22q11.2 deletion syndrome (22q11.2DS) is a neurogenetic condition associated with increased risk for schizophrenia. No study do date has explored how positive and negative symptoms of psychosis are distributed among individual patients with 22q11.2DS and if distinct patterns of symptoms can be identified. Negative symptoms being more frequent than positive symptoms in 22q11.2DS, we expected that a high number of patients would display predominant negative symptoms (PNS), whereas predominant positive symptoms would be less frequently reported. The present study aims at investigating the cognitive deficits and functional outcome associated with distinct patterns of psychotic symptoms in 22q11.2DS. 63 adolescents and young adults with 22q11.2DS participated in this study. Each participant underwent a clinical and a cognitive evaluation. A cluster analysis was used to identify groups of individuals with distinct patterns of symptoms. Individuals from the different clusters were then compared on a series of cognitive measures and on functional outcome. Three clusters of individuals were identified: low levels of symptoms, PNS, and high levels of symptoms. Individuals with PNS had significantly lower visual memory scores and decreased processing speed compared to participants with low levels of symptoms. They were also rated as having lower functional and occupational outcome. The present results indicate that one third of adolescents and young adults with 22q11.2DS display PNS. This pattern of symptoms was associated with specific cognitive deficits and decreased functional outcome. Future studies are needed to examine the developmental trajectories of these individuals and assess their risk of conversion to full-blown psychosis.

Incentive motivation deficits in schizophrenia reflect effort computation impairments during cost-benefit decision-making

BACKGROUND

Motivational impairments are a core feature of schizophrenia and although there are numerous reports studying this feature using clinical rating scales, objective behavioural assessments are lacking. Here, we use a translational paradigm to measure incentive motivation in individuals with schizophrenia.

METHODS

Sixteen stable outpatients with schizophrenia and sixteen matched healthy controls completed a modified version of the Effort Expenditure for Rewards Task that accounts for differences in motoric ability. Briefly, subjects were presented with a series of trials where they may choose to expend a greater amount of effort for a larger monetary reward versus less effort for a smaller reward. Additionally, the probability of receiving money for a given trial was varied at 12%, 50% and 88%. Clinical and other reward-related variables were also evaluated.

RESULTS

Patients opted to expend greater effort significantly less than controls for trials of high, but uncertain (i.e. 50% and 88% probability) incentive value, which was related to amotivation and neurocognitive deficits. Other abnormalities were also noted but were related to different clinical variables such as impulsivity (low reward and 12% probability). These motivational deficits were not due to group differences in reward learning, reward valuation or hedonic capacity.

CONCLUSIONS

Our findings offer novel support for incentive motivation deficits in schizophrenia. Clinical amotivation is associated with impairments in the computation of effort during cost-benefit decision-making. This objective translational paradigm may guide future investigations of the neural circuitry underlying these motivational impairments.

The role of negative symptoms in the context of cognitive remediation for schizophrenia

BACKGROUND

It has been suggested that the effect of cognitive remediation (CR) on functioning is mediated by the improvement in neurocognitive domains; especially executive function. However, the correlations are generally moderate and this has prompted the search for other mediators including negative symptoms (NS).

AIMS

To investigate whether the effect of CR on functioning could be mediated by executive function and/or NS.

METHOD

In a previous study, 62 outpatients with schizophrenia were randomized to 32 group sessions of REPYFLEC CR or leisure activities. Functioning (Life Skills Profile; LSP), NS (PANSS) and executive function (Behavioral Assessment of the Dysexecutive Syndrome; BADS) were measured at baseline and post-therapy. To assess how the effect of REPYFLEC CR is expressed in functioning at post-treatment, an autoregressive mediation model was employed.

RESULTS

There was a significant effect of the REPYFLEC CR compared with the control group in improving BADS total score and PANSS NS. There was also a significant association between NS and functioning while executive function was not significantly related to functioning. Finally, there was a significant intervention effect on functioning mediated by NS but not by executive function.

CONCLUSION

It is apparent that improving executive function does not lead directly to improved functional outcome and that NS might be closely linked to functioning in the context of our study.

A new Integrated Negative Symptom structure of the Positive and Negative Syndrome Scale (PANSS) in schizophrenia using item response analysis

BACKGROUND

Debate persists with regard to how best to categorize the syndromal dimension of negative symptoms in schizophrenia. The aim was to first review published Principle Components Analysis (PCA) of the PANSS, and extract items most frequently included in the negative domain, and secondly, to examine the quality of items using Item Response Theory (IRT) to select items that best represent a measurable dimension (or dimensions) of negative symptoms.

METHODS

First, 22 factor analyses and PCA met were included. Second, using a large dataset (n=7187) of participants in clinical trials with chronic schizophrenia, we extracted items loading on one or more PCA. Third, items not loading with a value of ≥ 0.5, or loading on more than one component with values of ≥ 0.5 were discarded. Fourth, resulting items were included in a non-parametric IRT and retained based on Option Characteristic Curves (OCCs) and Item Characteristic Curves (ICCs).

RESULTS

15 items loaded on a negative domain in at least one study, with Emotional Withdrawal loading on all studies. Non-parametric IRT retained nine items as an Integrated Negative Factor: Emotional Withdrawal, Blunted Affect, Passive/Apathetic Social Withdrawal, Poor Rapport, Lack of Spontaneity/Conversation Flow, Active Social Avoidance, Disturbance of Volition, Stereotyped Thinking and Difficulty in Abstract Thinking.

CONCLUSIONS

This is the first study to use a psychometric IRT process to arrive at a set of negative symptom items. Future steps will include further examination of these nine items in terms of their stability, sensitivity to change, and correlations with functional and cognitive outcomes.