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

Interview-based assessment of cognition in schizophrenia: applicability of the Schizophrenia Cognition Rating Scale (SCoRS) in different phases of illness and settings of care

INTRODUCTION

The Schizophrenia Cognition Rating Scale (SCoRS), an interview-based assessment of cognition, has proved to be a valid measure of cognitive performance in patients with schizophrenia.

OBJECTIVE

The aims of this study were to analyze the validity of this scale in a naturalistic setting representative of the Italian system of psychiatric care, and to test whether the SCoRS could be appropriately used in different phases of illness and contexts of care.

METHODS

Eighty-six patients with schizophrenia (DSM-IV-TR criteria) (N = 59 clinically stabilized patients; N = 27 recently hospitalized patients) were administered the SCoRS. The reliability of SCoRS was assessed and global ratings were correlated with neurocognitive, clinical, and psychosocial functioning measures.

RESULTS

SCoRS inter-rater and test-retest reliability were high. In clinically stabilized patients, SCoRS global ratings were significantly correlated with composite scores of cognitive performance (global cognitive index: r = -0.570, P<0.001), symptoms (Positive and Negative Syndrome Scale (PANSS) total score: r = 0.602, P < 0.001), and psychosocial functioning (Global Assessment of Functioning (GAF): r = -0.532, P<0.001; Health of the Nation Outcome Scale (HoNOS): r = 0.433, P < 0.001). On the other hand, no such correlations were found in recently hospitalized patients. Correlations with neuropsychological and functional measures were less significant as the severity of the patients' symptoms, especially positive symptoms, increased.

CONCLUSION

The SCoRS is a valid measure of cognitive performance and is related to psychosocial functioning, especially in clinically stable patients with schizophrenia. The usefulness of the SCoRS in patients recently admitted to hospital for an acute phase of illness is uncertain.

How specific are negative symptoms and cognitive impairment in schizophrenia? An analysis of PANSS and SCoRS

INTRODUCTION

Interview-based scales can be used as coprimary measures to complement the assessment of cognitive impairment in schizophrenia. One major question that arises from the use of such tools is how specific they are in relation to other psychopathological domains. We analyse the specificity of the Positive and Negative Syndrome Scale (PANSS) negative subscale and the Schizophrenia Cognition Rating Scale (SCoRS).

METHODS

We performed a principal component analysis (PCA) of PANSS negative subscale, rated by the interviewer, and SCoRS ratings from three different sources (patient, informant, and interviewer) in 101 patients with schizophrenia. Additionally, we correlated mean SCoRS ratings to PANSS negative subscale items to determine whether any PANSS item is particularly related to cognition.

RESULTS

The PCA showed that the two first components, which explained approximately 40% of the total variance of the scales, represent the SCoRS ratings and the PANSS negative subscale ratings, respectively. The mean interviewer SCoRS was significantly correlated with the PANSS negative Item 5 (difficulty in abstract thinking) and with the mean PANSS negative subscale. The latter correlation was no longer significant when "difficulty in abstract thinking" was eliminated from PANSS negative subscale.

CONCLUSIONS

In general, SCoRS and PANSS negative subscale scores address different constructs; however, the PANSS negative item "difficulty in abstract thinking" seems to address a cognitive dimension.

The relationship between internalized stigma, negative symptoms and social functioning in schizophrenia: the mediating role of self-efficacy

The broad aim of the present study was to gain a greater understanding of the processes that contribute to negative symptoms and social functioning in schizophrenia. More specifically, a theoretical model was proposed predicting that self-efficacy would mediate the relationship between internalized stigma and both negative symptoms and social functioning in schizophrenia. Initial analyses revealed that all variables were correlated. Specifically, internalized stigma was strongly correlated with negative symptoms, social functioning and self-efficacy. Furthermore, self-efficacy was strongly related to negative symptoms and moderately associated with social functioning. Further analyses however did not support the mediational role of self-efficacy. The theoretical and clinical implications of the findings, together with recommendations for future research, are outlined.

First episode psychosis patients show impaired cognitive function--a study of a South Asian population in the UK

BACKGROUND

Cognitive deficits are a core symptom of schizophrenia, severely debilitating and untreated by current medication. However, to date there is limited research focusing on the precise nature of the cognitive disturbances at first episode in ethnic populations. Improved understanding of this will allow improved approaches to therapy. The aim of this study was to investigate cognitive function with a first episode of psychosis South Asian patients.

METHODS

Twenty South Asian first episode psychosis patients and 15 healthy South Asian matched controls were recruited. All were second generation South Asian people living in the UK. Subjects who took part in the study completed the Positive and Negative Syndrome Scale (patient group), the Wechsler Test of Adult Reading and a battery of neuropsychological assessments to assess specific domains of cognition of relevance to Measurement and Treatment Research to Improve Cognition in Schizophrenia using the Cambridge Neuropsychological Test Automated Battery (CANTAB) (all groups).

RESULTS

Results show that first episode patients performed significantly worse than controls across all cognitive domains tested using CANTAB. Significant impairments were found in tests of visual and spatial memory, executive function, working memory, spatial planning and attention. Importantly, a number of cognitive performance indices (visual memory, spatial memory, executive function) were positively correlated with the severity of negative symptoms.

CONCLUSION

We demonstrate that first episode South Asian patients display significant and specific cognitive deficits with evidence to support an association between negative symptoms and certain cognitive domains at first episode in this patient population.

Ecological Momentary Assessment of social functioning in schizophrenia: impact of performance appraisals and affect on social interactions

Research concerning the complex interplay between factors that contribute to poor social functioning in schizophrenia has been hampered by limitations of traditional measures, most notably the ecological validity and accuracy of retrospective self-report and interview measures. Computerized Ecological Momentary Assessment (EMAc) permits the real-time assessment of relationships between daily life experiences, thoughts, feelings, and behaviors. In the current study, EMAc was used to record daily social interactions, subjective performance appraisals of these interactions (e.g., "I succeeded/failed"; "I was liked/rejected"), and affect in 145 individuals with schizophrenia or schizoaffective disorder. Participants completed electronic questionnaires on a personal digital assistant (PDA) four times per day for one week. Time-lagged multilevel modeling of the data revealed that more positive interaction appraisals at any point in a day were associated with greater positive affect which, in turn, was a strong predictor of more social interactions over subsequent hours. Social functioning, therefore, was linked to positive performance beliefs about social interactions that were associated with greater positive affect. The findings suggest a useful treatment target for cognitive behavioral therapy and other psychosocial interventions that can be used to challenge defeatist beliefs and increase positive affect to enhance social functioning in schizophrenia.

The Clinical Assessment Interview for Negative Symptoms (CAINS): final development and validation

OBJECTIVE

A major barrier to developing treatments for negative symptoms has been measurement concerns with existing assessment tools. Fulfilling the top recommendation of the National Institute of Mental Health's Consensus Development Conference on Negative Symptoms, the Clinical Assessment Interview for Negative Symptoms (CAINS) was developed using an iterative, empirical approach, and includes items assessing motivation, pleasure, and emotion expression. The authors employed multiple analytic techniques to develop the CAINS and here provide final development and validation results.

METHOD

The CAINS structure, interrater agreement, test-retest reliability, and convergent and discriminant validity were assessed in a large and diverse sample of 162 outpatients with schizophrenia or schizoaffective disorder recruited from four sites.

RESULTS

Three items with poor psychometric properties were removed, resulting in a 13-item CAINS. The CAINS factor structure was replicated, demonstrating two modestly correlated scales: expression (four items) and motivation/pleasure (nine items). The scales demonstrated good internal consistency, test-retest stability, and interrater agreement. Strong convergent validity was demonstrated by linkages with other negative symptom measures, self-report scales of sociality, pleasure, and motivation, and coded facial expressions. Discriminant validity was shown by independence from depression, medication side effects, and cognition. Notably, the CAINS scales were related to real-world vocational, independent living, and social/familial functioning.

CONCLUSIONS

The CAINS is an empirically developed and evaluated measure of negative symptoms. Findings indicate that the CAINS is brief yet comprehensive and employable across a wide range of research and clinical contexts.

Attaining and sustaining remission of predominant negative symptoms

BACKGROUND

Evidence is lacking on remission in the presence of predominant negative symptoms.

AIMS

To examine remission rates and their variation by antipsychotic medication in predominant negative symptoms.

METHODS

Data were reanalyzed on patients (n=383) who had participated in two double blind randomized placebo-controlled clinical trials of predominant negative symptoms lasting to 84 and 360days. Symptom remission was defined with the Remission in Schizophrenia Working Group remission criteria of attaining and maintaining mild ratings on eight SANS items. Remission rates were examined to 90days, survival analysis computed to ascertain time to attain symptom remission, binary logistic models used to predict the remission rate and 2 persistent months of symptom remission, and ANCOVA used to predict percent time in remission.

RESULTS

Symptomatic remission rates were: 22.72% at any visit during 90days, and 3.66% lasting 2months. Kaplan-Meier and Cox survival models to adjust for baseline symptom severity showed that compared with the placebo group the amisulpride group attained significantly (p<.05) more remission sooner (HR=2.321, 95% CI=1.36, to 3.97, p<.05). ANCOVA showed that compared with placebo the amisulpride group spent significantly (p<.05) more percent time in remission (ES=.28). Specificity analysis showed that: across trials the negative symptom remission rate was 25.1%; and in one 360-day trial the six-month remission criteria were attained and maintained by 6.4% of participants.

CONCLUSIONS

Presented with predominant negative symptoms the Working Group Remission criteria appear not to be a pragmatic therapeutic objective. Modified remission symptom and time criteria may be an effective way to examine remission.

Cognitive function in schizophrenia and its association with socio-demographics factors

BACKGROUND

Schizophrenia is a chronic and debilitating psychiatric illness consisting primarily of positive and negative symptoms. However, cognitive deficits in various domains have been consistently replicated in patients with schizophrenia. Therefore, the present study was designed to assess cognitive impairment in schizophrenia and to correlate the same with sociodemographic factors.

MATERIALS AND METHODS

Cognitive function in 100 patients with schizophrenia as per Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM IV-TR) criteria attending the psychiatry outpatient department (OPD) of Department of Psychiatry, SBKS MIRC was assessed using Addenbrooke's Cognitive Examination Revised (ACER) rating scale and Mini Mental State Examination (MMSE) and sociodemographic details was obtained using semistructured proforma. Data was analyzed by Chi-square and t-test.

RESULTS

About 70% patients of schizophrenia were found to have cognitive dysfunction for attention, concentration, memory, language, and executive function. Positive symptoms were associated with memory (P<0.001) and attention impairment (P<0.05). Patients with duration of illness >2 years and belonging to urban habitat showed more cognitive dysfunction. Male patients were associated with impairment in two domains of ACER: Language and memory.

CONCLUSION

The study findings depict that persistent cognitive deficits are seen in patients with schizophrenia. Its correlation with sociodemographic factors showed that patients with >2 years of illness and belonging to urban habitat showed more cognitive dysfunction. Male patients were associated with language and memory impairment. Our study recommends that the neurocognitive impairment should be included in the DSM-V diagnostic criteria for schizophrenia.

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.

Next-generation negative symptom assessment for clinical trials: validation of the Brief Negative Symptom Scale

The current study examined the psychometric properties of the Brief Negative Symptom Scale (BNSS), a next-generation rating instrument developed in response to the NIMH sponsored consensus development conference on negative symptoms. Participants included 100 individuals with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder who completed a clinical interview designed to assess negative, positive, disorganized, and general psychiatric symptoms, as well as functional outcome. A battery of anhedonia questionnaires and neuropsychological tests were also administered. Results indicated that the BNSS has excellent internal consistency and temporal stability, as well as good convergent and discriminant validity in its relationships with other symptom rating scales, functional outcome, self-reported anhedonia, and neuropsychological test scores. Given its brevity (13-items, 15-minute interview) and good psychometric characteristics, the BNSS can be considered a promising new instrument for use in clinical trials.

Delayed- and early-onset hypotheses of antipsychotic drug action in the negative symptoms of schizophrenia

The competing hypotheses that the action onset to antipsychotic medication assumes a course of early- or a delayed-response have been tested in positive and not negative symptoms in schizophrenia. The current study aims to test the early- and delayed-onset hypotheses with regard to negative symptoms. Data were re-analyzed from three clinical trials that compared placebo or amisulpride for up to 60 day. Participants had predominantly negative symptoms of schizophrenia (n=487). Response was examined with the incremental percentage Scale for the Assessment of Negative Symptoms (SANS) reduction over time. Response to the treatment, visit and treatment-visit interaction was assessed with mixed-modeling. Effect size differences on response between the amisulpride and placebo groups were reported at each visit. Across trials, mixed modeling showed that the incremental SANS reductions by the treatment-visit interaction that tests the action-onset hypothesis were not statistically significantly different across periods. The effect size differences of medication less placebo in the incremental percent SANS reduction showed non-significant differences based on overlapping confidence intervals with a moderate improvement at 8-14 day (ES=.33; 95% CI: -.07,.31), the least improvement at 28-30 day (ES=.12; 95% CI: -.07,.31), and a moderate improvement at 42-60 day to (ES=.39, 95%, CI: .19,.60). Generally, early- and delayed-response differences to antipsychotic were limited.

The Neurocognitive Phenotype of Apathy following Acquired Brain Damage

Apathy is one of the most common neuropsychiatric sequelae of acquired brain damage. The disorder is usually defined in terms of observed deficits in motivation related behavioural, emotional, and cognitive aspects of goal directed activity. Most neuropsychological research on apathy has focused primarily on its associated neurocognitive correlates; particularly those related to executive dysfunction, or its association with other clinical syndromes like depression. Results from these studies have been mixed, probably reflecting the use of different neuropsychiatric samples and assessment tools, or reflecting the differences in the conceptualisation of apathy across studies. In this study we ask whether performance on ‘standard’ executive tests would distinguish brain-damaged patients with apathy symptoms from those without apathy. To potentially strengthen the power of the possible relationships between apathy and executive function we included brain-injured patients with varied aetiologies, and used a much broader range of ‘executive function’ tests than in previous studies. Results indicate that the Tower of Hanoi puzzle is sensitive to apathy symptoms. Patients with apathy symptoms were significantly impaired on the task compared to non-apathetic patients. Performance on the Wisconsin Card Sorting test, the Hayling and Brixton tests, and the Stroop test failed to show this distinction. We discuss these findings and their implications for treatment and rehabilitation.

Ketamine-enhanced immobility in forced swim test: a possible animal model for the negative symptoms of schizophrenia

Schizophrenia is a chronic and highly complex psychiatric disorder characterised by cognitive dysfunctions, negative and positive symptoms. The major challenge in schizophrenia research is lack of suitable animal models that mimic the core behavioural aspects and symptoms of this devastating psychiatric disorder. In this study, we used classical and atypical antipsychotic drugs to examine the predictive validity of ketamine-enhanced immobility in forced swim test (FST) as a possible animal model for the negative symptoms of schizophrenia. We also evaluated the effects of a selective serotonin reuptake inhibitor (SSRI) on the ketamine-enhanced immobility in FST. Repeated administration of a subanaesthetic dose of ketamine (30 mg kg(-1), i.p., daily for 5 days) enhanced the duration of immobility in FST 24 h after the final injection. The effect, which persisted for at least 21 days after withdrawal of the drug, was neither observed by single treatment with ketamine (30 mg kg(-1) i.p.) nor repeated treatment with amphetamine (1 and 2 mg kg(-1) i.p., daily for 5 days). The enhancing effects of ketamine (30 mg kg(-1) day(-1) i.p.) on the duration of immobility in the FST were attenuated by clozapine (1, 5 and 10 mg kg(-1) i.p.), risperidone (0.25 and 0.5 mg kg(-1) i.p.) and paroxetine (1 and 5 mg kg(-1) i.p.). Haloperidol (0.25 and 0.50 mg kg(-1) day(-1) i.p.) failed to attenuate the ketamine-enhanced immobility in the FST. The repeated ketamine administration neither affects locomotor activity nor motor coordination in rats under the same treatment conditions with the FST, suggesting that the effects of ketamine on the duration of immobility in this study was neither due to motor dysfunction nor peripheral neuromuscular blockade. Our results suggest that repeated treatment with subanaesthetic doses of ketamine enhance the duration of immobility in FST, which might be a useful animal model for the negative symptoms (particularly the depressive features) of schizophrenia.

Predicting the severity of everyday functional disability in people with schizophrenia: cognitive deficits, functional capacity, symptoms, and health status

Disability is pervasive in schizophrenia and is refractory to current medication treatments. Inability to function in everyday settings is responsible for the huge indirect costs of schizophrenia, which may be as much as three times larger than direct treatment costs for psychotic symptoms. Treatments for disability are therefore urgently needed. In order to effectively treat disability, its causes must be isolated and targeted; it seems likely that there are multiple causes with modest overlap. In this paper, we review the evidence regarding the prediction of everyday disability in schizophrenia. We suggest that cognition, deficits in functional capacity, certain clinical symptoms, and various environmental and societal factors are implicated. Further, we suggest that health status variables, recently recognized as pervasive in severe mental illness, may also contribute to disability in a manner independent from these other better-studied causes. We suggest that health status be considered in the overall prediction of real-world functioning and that interventions aimed at disability reduction targeting health status may be needed, in addition to cognitive enhancement, skills training, and public advocacy for better services.

Cognitive changes following antidepressant or antipsychotic treatment in adolescents at clinical risk for psychosis

BACKGROUND

Improving neurocognitive abilities is a treatment priority in schizophrenia, however, pharmacological efforts to enhance deficits after illness onset have resulted in quite modest results that are of questionable clinical meaningfulness. Individuals at clinical risk for psychosis demonstrate neurocognitive impairments intermediate to the level of deficits observed in schizophrenia and normative performance, suggesting that a similar magnitude of improvement might result in more clinically meaningful change. In this study, we examined neurocognitive changes after six months of treatment in adolescents with clinical signs of risk for psychosis.

METHODS

Adolescents who were referred to the Recognition and Prevention program, which is focused on treatment and research for individuals at a clinical high risk for psychosis, were followed in a naturalistic treatment design. At study entry and approximately six months after starting treatment, we examined neuropsychological functioning and clinical symptoms for patients who remained off medications (OFF; N=27), started selective serotonin reuptake inhibitor antidepressant medication (AD; N=15), or started a second-generation antipsychotic medication (AP; N=11) within three months of study entry. We also included a locally recruited healthy comparison group (HC; N=17).

RESULTS

The clinical groups were not significantly different on baseline demographic, neurocognitive, or clinical symptom measures. Linear mixed models were used to examine cognitive changes, with time between assessments, depressive symptom severity, and attenuated positive symptom severity as random effects. Group by time effects were observed in sustained attention and verbal learning, with the AD group showing a more favorable response than the AP group. The AD group's improvements were not significantly different from the HC or OFF group.

CONCLUSION

Early intervention for those at clinical high risk for psychosis may result in neurocognitive improvements. These improvements were observed for those prescribed antidepressant, but not antipsychotic medications even though the groups did not differ in clinical symptom severity or treatment response.

Effects of an emotion management nursing program for patients with schizophrenia

PURPOSE

This study was to develop and examine the effects of an emotion management nursing program for schizophrenic patients.

METHODS

Fifty-two patients diagnosed as schizophrenia participated were recruited from community mental health facilities in Seoul, Korea. The experimental group received the Emotion Management Nursing Program for 90 minutes each week for total of 8 weeks. The data were collected from both from the experimental (n=22) and control groups (n=30). The research instruments were the Berkeley Expressivity Scale, an Emotional Behavior Scale, the Relationships Change scale, and Social Behavior Scale.

RESULTS

The experimental group showed a significant difference in emotional expression scores (t=3.267, P=.002), emotional behavior scores (F=61.65, P=.000), interpersonal relationship scores (t=4.012, P=.000), social behavior scores (t=-8.694, P=.000) than those in the control group.

CONCLUSIONS

The Emotion Management Nursing Program had positive influences on emotional management for schizophrenic patients, helping nurses to provide efficient evidence-based nursing care to the patients through the program.

Neural markers of early remission in first-episode schizophrenia: a volumetric neuroimaging study of the parahippocampus

Using voxel-based morphometry (VBM), our laboratory recently identified significantly lower grey matter concentration in the parahippocampal gyrus bilaterally in non-remitted patients with a first episode of psychosis (FEP) compared with remitted FEP patients. These results identified a localized difference but did not reveal which cortex (entorhinal, perirhinal, or parahippocampal), if any, was predominantly affected. So, the parahippocampal gyrus was manually segmented and grey matter volumes from the three cortices were compared between 42 non-remitted and 17 remitted patients with a first episode of schizophrenia (FES). Remission was defined as mild or less on eight key symptoms and maintained for 6 consecutive months following the 2005 consensus definition. The non-remitted patients displayed smaller volumes in the parahippocampal cortex - trend-level difference on the left [mm(3), mean (S.D.): non-remitted=2486 (413); remitted=2775 (593)] and significant difference on the right [mm(3), mean (S.D.): non-remitted=2546 (463); remitted=2926 (525)]. No notable differences were found in the entorhinal or perirhinal cortices. This result supported our VBM finding of reduced parahippocampal grey matter bilaterally in non-remitted patients and further suggested differences may be selectively limited to the parahippocampal cortex. A smaller parahippocampal cortex may represent a neural marker in FES patients who do not achieve remission after 1 year of treatment.

Schizophrenia as a disorder of too little dopamine: implications for symptoms and treatment

Antipsychotics represent the first effective therapy for schizophrenia, with their benefits linked to dopamine D2 blockade. Schizophrenia was soon identified as a hyperdopaminergic disorder, and antipsychotics proved to be reasonably effective in controlling positive symptoms. However, over the years, schizophrenia has been reconceptualized more broadly, now defined as a heterogeneous disorder with multiple symptom domains. Negative and cognitive features, not particularly responsive to antipsychotic therapy, have taken on increased importance--current thinking suggests that these domains predate the onset of positive symptoms and are more closely tied to functional outcome. That they are better understood in the context of decreased dopamine activity suggests that schizophrenia may fundamentally represent a hypodopaminergic disorder. This shift in thinking has important theoretical implications from the standpoint of etiology and pathophysiology, but also clinically in terms of treatment and drug development.

Neurodevelopmental liability to schizophrenia: the complex mediating role of age at onset and premorbid adjustment

Large individual variation in the clinical presentation of schizophrenia-spectrum disorders raises key questions regarding their aetiological underpinnings. In this respect, age at onset of the disorder is a particularly interesting marker of liability, as it has been reported to be associated with other signs of developmental compromise, such as male gender, increased presence of familial history of psychosis and poor premorbid adjustment, as well as a more severe clinical outcome in terms of cognition and symptomatology. The association between these variables has encouraged a neurodevelopmental perspective of the aetiological mechanisms involved in the pathophysiology of schizophrenia. However, the complex relationships within neurobiological liability markers, and between these markers and clinical outcome, remain to be understood. In the present study, we used a path-analytic approach to explore: i) the fit of the model to observed data; and both ii) direct and iii) indirect associations between the variables. In a sample of 106 patients with schizophrenia-spectrum disorders, we found a good fit of the model to the observed data, providing further evidence that supports a neurodevelopmental pathway to the disease in a subgroup of patients. However, the most parsimonious model showed complex relationships, where age at onset and premorbid functioning acted as mediators between gender, familial history of psychosis and clinical outcome. These findings refine earlier explanations of the neurobiological basis of schizophrenia, with potential applications in genetic studies based on more homogeneous forms of the disease. We further discuss the putative implications of our results in clinical practice and prevention policies.

Associations of serum brain-derived neurotrophic factor with cognitive impairments and negative symptoms in schizophrenia

Brain-derived neurotrophic factor (BDNF) may be involved in the pathophysiology of schizophrenia. The aim of this study was to examine the associations of serum BDNF levels with the cognition and clinical characteristics in patients with schizophrenia. Sixty-three patients with schizophrenia and 52 age- and sex-matched healthy controls were examined with neuropsychological tests. Serum BDNF levels were determined by enzyme-linked immunosorbent assay (ELISA). There were no significant differences in serum BDNF levels between normal controls and patients with schizophrenia. Serum BDNF levels of normal controls showed negative correlations with verbal working memory, but this was not the case with schizophrenic patients. Meanwhile, serum BDNF levels of schizophrenic patients showed positive correlations with the scores of the Scale for the Assessment of Negative Symptoms (SANS) and the Information subtest scores of Wechsler Adult Intelligence Scale Revised (WAIS-R). Serum BDNF levels are related with the impairment of verbal working memory and negative symptoms in patients with schizophrenia.

Apathy, cognitive deficits and functional impairment in schizophrenia

INTRODUCTION

Apathy has been repeatedly highlighted as a core component of negative symptoms especially with regard to functional outcome of schizophrenia. The purpose of this study was to explore the relationships between apathy, cognitive deficits, and psychosocial functioning in chronic patients with schizophrenia.

METHODS

Thirty-six chronic patients with schizophrenia and an equal number of matched healthy participants were assessed with the clinician version of Apathy Evaluation Scale (AES-C) along with a comprehensive battery of neuropsychological measures. Functioning was assessed with the Personal and Social Performance scale (PSP) and other symptoms were measured with the Positive and Negative Syndrome Scale and the Calgary Depression Scale for Schizophrenia.

RESULTS

Apathy was strongly and specifically associated with poorer performance on executive tests in patient group. AES-C was significantly correlated with PSP total score as well as its subscales for social useful activities, personal and social relationships, and self-care. Multiple regression analysis revealed that apathy was the most robust predictor of current psychosocial functioning, accounting for 70% of the variance in functioning, independently of co-existent cognitive deficits. Moreover, executive dysfunction did not predict functional impairment, independently of the effect of apathy.

CONCLUSION

Our findings confirm that apathy has a stronger relationship to functional impairment than cognitive deficits on a cross-sectional basis in schizophrenia. Moreover, they suggest that apathy and executive dysfunction might represent different manifestations of the same syndrome, probably sharing a common neural substrate.

Persistent negative symptoms in first-episode schizophrenia: a prospective three-year follow-up study

BACKGROUND

Negative symptoms are a core feature of schizophrenia. The evolution and trajectory of primary negative symptoms were under-studied. We aimed at evaluating the prevalence and stability of primary negative symptoms, and factors associated with persistent primary negative symptoms in a first-episode sample.

METHOD

Ninety-three Hong Kong Chinese aged 18 to 55 years presenting with first-episode schizophrenia-spectrum disorder were studied. Data on premorbid adjustment, socio-demographics, and baseline clinical and cognitive profiles were obtained. Psychopathological and vocational reassessments were conducted at 12, 24 and 36 months. Primary negative symptoms were defined as the presence of clinically significant negative symptoms excluding depression and extra-pyramidal signs.

RESULTS

At baseline, 25.8% of subjects exhibited primary negative symptoms. A quarter of patients had their initial primary negative symptoms status retained 12 months after treatment initiation. In both Year 2 and Year 3 of study period, around 70% of subjects had their primary negative symptoms status maintained for 12 months. At the end of three-year follow-up, 23.7% were categorized as having persistent primary negative symptoms. Male sex, unemployment at intake, prolonged duration of untreated psychosis, poorer premorbid academic and social functioning, poorer insight and worse vocational outcome were found to be associated with persistent primary negative symptoms.

CONCLUSION

Clinical status of primary negative symptoms in first-episode schizophrenia-spectrum disorder was unstable in the initial year of treatment. Baseline symptom assessment may not reliably predict development of persistent primary negative symptoms. Studying negative symptoms should take into account the longitudinal perspective, especially in the early course of psychotic disorders.

Clinical and Cognitive Insight in a Compensatory Cognitive Training Intervention

The impact of limited insight is a crucial consideration in the treatment of individuals with psychiatric illness. In the context of psychosis, both clinical and cognitive insight have been described. This study aimed to evaluate the relationships between clinical and cognitive insight and neuropsychological functioning, psychiatric symptom severity, and everyday functioning in patients with a primary psychotic disorder participating in a compensatory cognitive training (CT) intervention. Sixty-nine individuals diagnosed with a primary psychotic disorder were randomized to a 3-month CT intervention or to standard pharmacotherapy, and they completed a comprehensive neuropsychological, clinical, and functional battery at baseline, 3 months, and 6 months. The CT intervention focused on habit formation and compensatory strategy learning in four domains: prospective memory, attention and vigilance, learning and memory, and problem-solving/cognitive flexibility. At baseline, better clinical insight was significantly related to better executive functioning and less severe negative symptoms. There was no significant association between cognitive insight and cognitive functioning, symptom severity, or everyday functioning ability. The CT intervention did not have an effect on clinical or cognitive insight, but better cognitive insight prior to participation in CT significantly predicted decreased positive and depressive symptom severity posttreatment, and better clinical insight predicted improved self-reported quality of life. Although clinical insight is related to executive functioning, the correlates of cognitive insight remain elusive. Intact insight appears to be beneficial in ameliorating clinical symptomatology like positive symptoms and depression, rather than augmenting cognition. It may be valuable to develop brief interventions aimed at improving clinical and cognitive insight prior to other psychosocial rehabilitation in order to maximize the benefit of treatment.

Compensatory cognitive training for psychosis: who benefits? Who stays in treatment?

Enhancing cognitive performance to improve functioning in schizophrenia is a fundamental research priority. Previous investigations have demonstrated that various types of cognitive training (CT) can improve neuropsychological performance, psychosocial functioning, and psychiatric symptom severity. However, there is limited information about individual differences that may predict CT response and adherence to treatment. The purpose of this study was to identify who is likely to drop out of this type of study as well as this type of intervention and to explore individual factors predicting treatment outcome. Participants included 89 outpatients diagnosed with a primary psychotic disorder who enrolled in a randomized controlled trial of compensatory CT and were assessed at baseline, 3 months (posttest), and 6 months (follow-up). Study completers had more formal education and lower daily doses of antipsychotic medications than did dropouts with no CT exposure, but the groups did not otherwise differ. There were no significant differences between participants who completed CT and those who began CT but later dropped out. CT-associated improvement was correlated with worse baseline scores on measures of cognitive performance, symptom severity, functional capacity, and self-rated quality of life, cognitive problems, and strategy use. These results suggest that those with lower baseline functioning may have more room to improve following CT. The pattern of correlations in this sample indicated that many types of individuals can improve with CT treatment, including older patients.

Negative expectancy appraisals and defeatist performance beliefs and negative symptoms of schizophrenia

Negative symptoms have clear functional implications in schizophrenia and are typically unresponsive to current treatments. The cognitive model of negative symptoms suggests that dysfunctional beliefs are influential in the development and maintenance of negative symptoms and schizophrenia. The current study reports on a preliminary investigation of a new measure of Negative Expectancy Appraisals (specifically beliefs about limited probability of success and perception of limited cognitive resources), and also evaluates whether dysfunctional beliefs are more closely linked to particular subdomains of negative symptoms. Sixty two individuals with schizophrenia completed measures of dysfunctional beliefs and were rated on negative symptoms. Analyses indicated that the endorsement of beliefs regarding low expectations for success and perception of limited resources (Negative Expectancy Appraisals) are robustly associated with diminished experience negative symptoms (avolition, asociality, and anhedonia), but are not associated with negative symptoms reflecting diminished expressivity (blunted affect, alogia). Similarly, Defeatist Performance Beliefs are modestly related to diminished experience, but not diminished expression, negative symptoms. Negative Expectancy Appraisals were also robustly linked to depressive symptoms. Results from the current study provide evidence that dysfunctional beliefs are clearly relevant to consider in relation to negative symptoms, and may represent a fruitful treatment target.

Factors involved in the level of functioning of patients with schizophrenia according to latent variable modeling

PURPOSE

This study aimed at using latent variable modelling to explore the significantly contributing variables to functioning in schizophrenia patients.

METHODS

The study cohort comprised 296 schizophrenia patients evaluated once for demographic characteristics, functioning (FROGS, SWN-K, QLS) and symptomatology (Positive and Negative Syndrome Scale [PANSS]). First exploratory multivariate analyses were conducted and then a model with functioning as a latent variable was proposed and tested with the data.

RESULTS

Symptomatology as negative, cognitive and excitation factor are significant predictors of functioning assessed through FROGS (P<0.0001), SWN-K and QLS (P<0.001). The model was constructed with functioning defined as a latent variable, indicators are subscores on FROGS, SWN-K, QLS and exogenous variable included symptomatology, Duration of Untreated Psychosis (DUP) and educational level.

CONCLUSION

Using the five clinical dimensions of the PANSS, (Positive, Negative, Cognitive, Anxiety/Depression and Excitation) the negative and cognitive dimensions are highly correlated via the latent variable to the three dimensions of functioning evaluated by the FROGS: "daily life", "social functioning" and "treatment" and the QLS subscores (interpersonnal, common object, instrumental role). Educationnal level is positively linked to functioning but not DUP. The model emphasizes the need for treatment strategies that have an effect on cognitive-factors, to improve functioning in schizophrenia.

Heterogeneity of auditory verbal working memory in schizophrenia

The heterogeneity of schizophrenia remains an obstacle for understanding its pathophysiology. Studies using a tone discrimination screening test to classify patients have found evidence for 2 subgroups having either a specific deficit in verbal working memory (WM) or deficits in both verbal and nonverbal memory. This study aimed to (a) replicate in larger samples differences between these subgroups in auditory verbal WM; (b) evaluate their performance on tests of explicit memory and sustained attention; (c) determine the relation of verbal WM deficits to auditory hallucinations and other symptoms; and (d) examine medication effects. The verbal WM and tone discrimination performance did not differ between medicated (n = 45) and unmedicated (n = 38) patients. Patients with schizophrenia who passed the tone screening test (discriminators; n = 60) were compared with those who did not (nondiscriminators; n = 23) and healthy controls (n = 47). The discriminator subgroup showed poorer verbal WM than did controls and a deficit in verbal but not visual memory on the Wechsler Memory Scale-Revised (Wechsler, 1987), whereas the nondiscriminator subgroup showed overall poorer performance on both verbal and nonverbal tests and a marked deficit in sustained attention. Verbal WM deficits in discriminators were correlated with auditory hallucinations but not with negative symptoms. The results are consistent with a verbal memory deficit in a subgroup of schizophrenia having intact auditory perception, which may stem from dysfunction of language-related cortical regions, and a more generalized cognitive deficit in a subgroup having auditory perceptual and attentional dysfunction.

Inflammatory processes in schizophrenia: a promising neuroimmunological target for the treatment of negative/cognitive symptoms and beyond

Emerging evidence indicates that schizophrenia is associated with activated peripheral and central inflammatory responses. Such inflammatory processes seem to be influenced by a number of environmental and genetic predisposition factors, and they may critically depend on and contribute to the progressive nature of schizophrenic disease. There is also appreciable evidence to suggest that activated inflammatory responses can undermine disease-relevant affective, emotional, social, and cognitive functions, so that inflammatory processes may be particularly relevant for the precipitation of negative and cognitive symptoms of schizophrenia. Recent clinical trials of anti-inflammatory pharmacotherapy in this disorder provide promising results by showing superior beneficial treatment effects when standard antipsychotic drugs are co-administered with anti-inflammatory compounds, as compared with treatment outcomes using antipsychotic drugs alone. Given the limited efficacy of currently available antipsychotic drugs to ameliorate negative and cognitive symptoms, the further exploration of inflammatory mechanisms and anti-inflammatory strategies may open fruitful new avenues for improved treatment of symptoms undermining affective, emotional, social and cognitive functions pertinent to schizophrenic disease.

The contribution of epidemiology to defining the most appropriate approach to genetic research on schizophrenia

Psychosis is thought to have a strong genetic component, but many efforts to discover the underlying putative schizophrenia genes have yielded disappointing results. In fact, no strong associations emerged in the first genome-wide association studies in psychiatry and weakly observed associations were not related to the candidate genes identified in previous studies. These partially successful findings may be explained by the fact that genetic research in psychiatry suffers from confounding issues related to phenotype definition, the considerable degree of phenotypic variability and diagnostic uncertainty, absence of specific neuropathological features and environmental influences. To make progress it is first necessary to deconstruct psychosis based on symptomatology, and then to correlate particular phenotypes with genetic variants. Moreover, it is time to conduct studies that define persistent aspects of the schizophrenic profile that are more likely to represent an underlying biological pathogenesis, as opposed to fluctuating symptoms that are possibly environmentally mediated. In fact, progress in understanding the etiology of schizophrenia will depend upon the availability of good measures of genetic liability as well as relevant environmental exposures during critical periods of an individual's life. If environmental and/or genetic factors are not precisely measured, it is impossible to study their independent effects or interactions.

The parahippocampal gyrus as a neural marker of early remission in first-episode psychosis: a voxel-based morphometry study

INTRODUCTION

Outcome from psychotic disorders is heterogeneous with poor long-term clinical outcome associated with such markers as decreased internal capsule volume and increased ventricular volumes. No previous study has examined neuroimaging markers in relation to early remission.

METHODS

This neuroimaging study included 68 previously untreated first episode of psychosis (FEP) patients, of whom 28 achieved remission and 40 did not after six months of treatment, and 42 healthy controls. Using voxel-based morphometry (VBM), we set out to determine if specific neural correlates could be identified in FEP patients not achieving remission in a specialized early-intervention service.

RESULTS

Nonremitted patients had significant lower grey matter concentration (GMC) in the parahippocampal gyrus bilaterally compared to remitted patients. A classification model utilizing parahippocampal GMC correctly classified remission status 79% of the time and accounted for 56% of the variance. Moreover, GMC on the left (r=-0.35, p=0.004) and right (r=-0.47, p<0.0001) side correlated with social withdrawal while only the left side correlated with verbal memory (r=0.21, p=0.03).

CONCLUSIONS

Neural markers of early remission are present in first-episode patients. A better understanding of the neural etiology of psychosis and its relationship to outcome may encourage the search for new medications to help improve outcome in relation to the identified brain regions like the parahippocampal gyrus.

Activities of daily living, social functioning and their determinants in persons with psychotic disorder

OBJECTIVE

The determinants of everyday functioning in persons with psychotic disorder have not been widely studied in community dwelling samples. Our aim was to investigate limitations in everyday functioning among subjects with psychotic disorders in a population-based study.

METHOD

Everyday functioning was assessed in a nationally representative sample of 7112 persons aged 30+ using interviewer observations and self-reports, while verbal fluency and memory were also measured. Diagnostic assessment of DSM-IV psychotic disorders was based on SCID interview and case-note data. Lifetime-ever diagnoses of psychotic disorder were classified into schizophrenia (n=61), other non-affective psychotic disorders (ONAP) (n=79) and affective psychoses (n=45).

RESULT

Non-affective psychotic disorder was significantly associated with limitations in everyday functioning, as well as with deficits in verbal fluency and memory. Negative symptoms, depression, age, gender, verbal memory deficits, and reduced visual acuity were predictors of limitations in everyday functioning even after controlling for sociodemographic factors and chronic medical conditions, and difficulties in social functioning were also related to expressive speech problems.

CONCLUSION

Persons with schizophrenia and ONAP have significantly more problems in everyday functioning than the general population. One significant predictor of problems was reduced visual acuity, which at least in some situations could be easily corrected.

Toward the next generation of negative symptom assessments: the collaboration to advance negative symptom assessment in schizophrenia

Negative symptoms in schizophrenia are related to poor functional outcome, persistent over time, a source of burden for caregivers, and only minimally responsive to currently available medications. A major challenge to developing efficacious interventions concerns the valid and reliable assessment of negative symptoms. In a recent consensus statement on negative symptoms, a central recommendation was the need to develop new assessment approaches that address the limitations of existing instruments. In the current report, we summarize the background and rationale for the Collaboration to Advance Negative Symptom Assessment in Schizophrenia (CANSAS). The CANSAS project is an National Institute of Mental Health-funded multisite study that is constructing a next-generation negative symptom scale, the Clinical Assessment Interview for Negative Symptoms (CAINS). The CAINS is being developed within a data-driven iterative process that seeks to ensure the measure's reliability, validity, and utility for both basic psychopathology and treatment development research.

A path model investigation of neurocognition, theory of mind, social competence, negative symptoms and real-world functioning in schizophrenia

Problems in real-world functioning are pervasive in schizophrenia and much recent effort has been devoted to uncovering factors which contribute to poor functioning. The goal of this study was to examine the role of four such factors: social cognition (theory of mind), neurocognition, negative symptoms, and functional capacity (social competence). 178 individuals with schizophrenia or schizoaffective disorder completed measures of theory of mind, neurocognition, negative symptoms, social competence, and self-reported functioning. Path models sought to determine the relationships among these variables. Theory of mind as indexed by the Hinting Task partially mediated the relationship between neurocognition and social competence, and negative symptoms and social competence demonstrated significant direct paths with self-reported functioning. Study results suggest theory of mind serves as an important mediator in addition to previously investigated social cognitive domains of emotional and social perception. The current study also highlights the need to determine variables which mediate the relationship between functional capacity and real-world functioning.

Metacognition as a mediator of the effects of impairments in neurocognition on social function in schizophrenia spectrum disorders

OBJECTIVE

This study explored whether Mastery, a domain of metacognition that reflects the ability to use knowledge about mental states to respond to psychological challenges, mediated the effects of neurocognition on the frequency of social contact and persons' capacity for social relatedness.

METHOD

Participants were 102 adults with schizophrenia or schizoaffective disorder. Neurocognition was represented by a single factor score produced by a principal components analysis of a neurocognitive test battery. Mastery was assessed using the metacognitive assessment scale and social functioning by the quality of life scale.

RESULTS

Using structural equation modeling, specifically measured-variable path analysis, a mediational model consisting of neurocognitive capacity linked to mastery and capacity for social relationships and mastery linked with frequency of social contact and capacity for social relatedness showed acceptable fit to the observed data. This persisted after controlling for negative and cognitive symptoms.

CONCLUSION

Results suggest that certain forms of metacognition mediate the influence of neurocognition upon function in schizophrenia.

DISC1 regulates primary cilia that display specific dopamine receptors

Background

Mutations in the DISC1 gene are strongly associated with major psychiatric syndromes such as schizophrenia. DISC1 encodes a cytoplasmic protein with many potential interaction partners, but its cellular functions remain poorly understood. We identified a role of DISC1 in the cell biology of primary cilia that display disease-relevant dopamine receptors.

Methodology/Principal Findings

A GFP-tagged DISC1 construct expressed in NIH3T3 cells and rat striatal neurons localized near the base of primary cilia. RNAi-mediated knockdown of endogenous DISC1 resulted in a marked reduction in the number of cells expressing a primary cilium. FLAG-tagged versions of the cloned human D1, D2 and D5 dopamine receptors concentrated highly on the ciliary surface, and this reflects a specific targeting mechanism specific because D3 and D4 receptors localized to the plasma membrane but were not concentrated on cilia.

Conclusions/Significance

These results identify a role of DISC1 in regulating the formation and/or maintenance of primary cilia, and establish subtype-specific targeting of dopamine receptors to the ciliary surface. Our findings provide new insight to receptor cell biology and suggest a relationship between DISC1 and neural dopamine signaling.

Executive function needs to be targeted to improve social functioning with Cognitive Remediation Therapy (CRT) in schizophrenia

While the role of impaired cognition in accounting for functional outcome in schizophrenia is generally established, the relationship between cognitive and functional change in the context of treatments is far from clear. The current paper tries to identify which cognitive changes lead to improvements in daily functioning among persons with chronic schizophrenia who had current negative symptoms and evidenced neuropsychological impairments. In a previous work, Cognitive Remediation Therapy (CRT) was compared with a control therapy, involving similar length of therapist contact but different targets. At the end of treatment, CRT conferred a benefit to people with schizophrenia in cognition and functioning [Schizophrenia Research, 87 (2006) 323-331]. Subsequently, analyses of covariance (ANCOVA) were conducted with baseline and cognitive change scores as covariates to test whether cognitive change predicted change in functioning. Additionally, statistical tests to establish the mediation path with significant variables were performed. Although verbal memory, but not executive functioning, was associated with functioning at baseline, it was the improvement in executive functioning that predicted improved daily functioning. Verbal memory played a mediator role in the change process. Consequently, in order to improve daily functioning with CRT, executive function still needs to be targeted in despite of multiple cognitive impairments being present.

Circumstances under which practice does not make perfect: a review of the practice effect literature in schizophrenia and its relevance to clinical treatment studies

In this article, we review the literature on practice effects in schizophrenia, an underappreciated confound in interpreting cognitive improvement in clinical trials. We first examine claims regarding first- and second-generation antipsychotic medications as cognitive enhancers, and follow it with a discussion of recent studies demonstrating how practice or placebo effects may drive 'positive' findings. Thus, this review suggests that many previous findings can be reinterpreted in this light. Critically, we also make several suggestions about test construction, study design, and statistical analyses that the field might use to overcome this potential confound. Our suggestions may also have implications for drug discovery and regulatory approval of cognitive-enhancing adjunctive agents, in terms of study design and/or test psychometric characteristics, including the development of tests that are relatively insensitive to practice-related changes. Such advances might be important for improving the methodology involved in the assessment of cognitive change in treatment studies.

Negative symptoms and concomitant attention deficits in schizophrenia: associations with prospective assessments of anxiety, social dysfunction, and avoidant coping

BACKGROUND

Negative symptoms are a significant barrier to function and may have a range of etiological roots and links to outcome. A previous study identified a subgroup of patients with schizophrenia who had both higher levels of negative symptoms and relatively poorer attentional function who had uniquely lower self-esteem and greater internalized stigma.

AIMS

To determine whether participants previously classified as having High Negative/Poorer Attention would continue to have lower self-esteem, higher self-stigma, and also higher levels of anxiety and avoidant coping 5 months later.

METHOD

Participants were 77 (77.8%) of the original 99 participants who completed follow-up procedures.

RESULTS

The High Negative/Poorer Attention group had significantly poorer social functioning, lower appraisal of their competence, higher levels of anxiety, and a higher preference for ignoring stressors five months after classification.

CONCLUSIONS

Negative symptoms with concomitant attention deficits may lead to more social and psychological dysfunction than negative symptoms or attention deficits alone. Individuals with both high levels of negative symptoms and poor attention may represent a meaningful subgroup with unique psychosocial difficulties that persist over time.

Mutant mouse models: genotype-phenotype relationships to negative symptoms in schizophrenia

Negative symptoms encompass diminution in emotional expression and motivation, some of which relate to human attributes that may not be accessible readily in animals. Additionally, their refractoriness to treatment precludes therapeutic validation of putative models. This review considers critically the application of mutant mouse models to the study of the pathobiology of negative symptoms. It focuses on 4 main approaches: genes related to the pathobiology of schizophrenia, genes associated with risk for schizophrenia, neurodevelopmental-synaptic genes, and variant approaches from other areas of neurobiology. Despite rapid advances over the past several years, it is clear that we continue to face substantive challenges in applying mutant models to better understand the pathobiology of negative symptoms: the majority of evidence relates to impairments in social behavior, with only limited data relating to anhedonia and negligible data concerning avolition and other features; even for the most widely examined feature, social behavior, studies have used diverse assessments thereof; modelling must proceed in cognizance of increasing evidence that genes and pathobiologies implicated in schizophrenia overlap with other psychotic disorders, particularly bipolar disorder. Despite the caveats and challenges, several mutant lines evidence a phenotype for at least one index of social behavior. Though this may suggest superficially some shared relationship to negative symptoms, it is not yet possible to specify either the scope or the pathobiology of that relationship for any given gene. The breadth and depth of ongoing studies in mutants hold the prospect of addressing these shortcomings.

Negative symptoms in schizophrenia: avolition and Occam's razor

The identification of schizophrenia's negative symptoms dates back to the earliest descriptions of Kraepelin and Bleuler, who each highlighted the central role of avolition in the phenomenology and course of this illness. Since, there have been numerous advances in our understanding of schizophrenia, and the present review tracks the changes that have taken place in our understanding of negative symptoms, their description and measurement. That these symptoms represent a distinct domain of the illness is discussed in the context of their ties to other symptoms and functional outcome. The underlying structure of the negative symptom construct is explored, including several lines of investigation that point towards diminished expression and amotivation as key underlying subdomains. We also discuss findings of intact emotional experience and consummatory pleasure in individuals with schizophrenia, calling into question the presence of anhedonia in this illness. We conclude with a reconceptualization of the negative symptoms, suggesting amotivation (ie, avolition) represents the critical component, particularly in regard to functional outcome. Further exploration and clarification of this core deficit will ultimately enhance our neurobiological understanding of schizophrenia, as well as strategies that may improve outcome.

MK-801 produces a deficit in sucrose preference that is reversed by clozapine, D-serine, and the metabotropic glutamate 5 receptor positive allosteric modulator CDPPB: relevance to negative symptoms associated with schizophrenia?

Currently prescribed antipsychotics attenuate the positive symptoms of schizophrenia but fail or only mildly improve negative symptoms. The present study aimed to establish an animal model of negative symptoms by examining the effects of the NMDA receptor antagonist MK-801 on sucrose preference. We sought to validate the model by examining the effects of clozapine and D-serine, for which there are positive clinical data regarding their effects on negative symptoms, and haloperidol which is clinically ineffective. We extended our analysis by examining CDPPB, an mGlu5 receptor positive allosteric modulator. Acute MK-801 produced effects indicative of a shift in the hedonic experience of sucrose not confounded by disruptions in motor abilities or taste as revealed by: 1) a decrease in sucrose intake at low concentrations (0.8% or 1.2%), but no effect on water, 2) an increase in consumption for higher (7%) sucrose concentrations, reflecting a shift to the right in the concentration-consumption curve, and 3) no effect on quinine intake. Sub-chronic clozapine and acute d-serine attenuated the MK-801-induced deficit in 1.2% sucrose consumption, whereas sub-chronic haloperidol (0.02 mg/kg) did not. Finally, acute treatment with CDPPB also attenuated this deficit. These data suggest that this model may be useful for identifying novel agents that improve negative symptoms, and that compounds which enhance NMDA receptor function, such as mGlu5 receptor PAMs, may have clinical utility in this regard.

Progress in defining optimal treatment outcome in schizophrenia

Historically, schizophrenia has been associated with early-onset, persistent symptoms, and progressive decline accompanied by poor functional recovery. The advent of effective drugs in the 1950s improved symptom control, at least from the standpoint of positive features (e.g. hallucinations, delusions). However, even here the response was limited and efficacy in other symptom domains (cognitive, deficit/negative) was minimal. With clozapine as the prototype, the second-generation antipsychotics arrived in the 1990s with claims of improved tolerability, as well as greater and broader clinical efficacy, all of which was to translate to gains in functional outcome and quality of life. The capacity of these drugs to effect such changes has since been tempered, but it remains that the research and hope generated served as an impetus to redefine outcomes. A medical-based model, centred on pharmacotherapy and symptom resolution, has given way to a re-conceptualization of schizophrenia and treatment goals. There is a clearer distinction between clinical and functional outcomes, and, with this, greater attention has been given to these other symptom domains that curtail improvement in the latter. At the same time, a concerted shift to shared decision making has underscored quality-of-life issues that benefit from, but cannot be guaranteed by, either clinical or functional improvement. To this end, the field has now embraced a recovery model that is seen as a process, multidimensional and individualized, rather than dichotomous and symptom driven.

The role of effort, cognitive expectancy appraisals and coping style in the maintenance of the negative symptoms of schizophrenia

The aim of the present study was to assess the role of psychological factors, specifically effort, coping, and negative expectancy appraisals, in addition to executive functioning and depression, in accounting for negative symptoms broadly defined. Fifty inpatients with acute schizophrenia participated in a study with a cross-sectional design. All of the psychological variables had significant partial correlations with some of the measures of negative symptoms when depression was controlled. A series of multiple regression analyses indicated that executive functioning only made a significant unique contribution to the prediction of affective flattening, whereas psychological factors made unique contributions to the variance in each of the negative symptom subscales apart from affective flattening, as well as to the negative symptom total score, accounting for 9% to 19% of the variance. These results suggest that, in addition to neuropsychological variables, psychological variables are important for understanding negative symptoms in acute schizophrenia.

Pathways to functional outcomes in schizophrenia: the role of premorbid functioning, negative symptoms and intelligence

BACKGROUND

Social and intellectual premorbid functioning are generally estimated retrospectively, and related to clinical or hospitalization outcomes in schizophrenia. Yet the relationship between premorbid functioning assessed prior to psychiatric hospitalization and postmorbid functional outcomes has not been examined.

OBJECTIVES

To test competing models of the relationship between (a) functional outcomes with (b) premorbid functioning assessed on nationally administered tests prior to psychiatric hospitalization, postmorbid intellectual functioning and symptomatology using a historical prospective design.

METHODS

Ninety one inpatient and outpatient males with schizophrenia or schizoaffective disorder, aged 19 to 35, were examined using the Positive and Negative Syndrome Scale, the WAIS-III and Strauss and Carpenter social and occupational functional outcome scale. Premorbid intelligence and social functioning data were obtained from national standardized tests administered during high school prior to first hospitalization for schizophrenia.

RESULTS

Path modeling showed that premorbid intelligence and behavioral functioning directly predicted postmorbid IQ and negative symptoms, and indirectly predicted postmorbid social and occupational functioning via negative symptoms. Item level analysis indicated that better social and occupational outcomes occurred in a group with few negative symptoms.

CONCLUSIONS

Premorbid functioning, postmorbid IQ and negative symptoms are related, yet the relationship between premorbid functioning and postmorbid functional outcomes appears to be mediated by postmorbid negative symptoms.