Course of schizophrenia: neuropsychological evidence for a static encephalopathy

Use of the Chinese version of the MATRICS Consensus Cognitive Battery to assess cognitive functioning in individuals with high risk for psychosis, first-episode schizophrenia and chronic schizophrenia: a systematic review and meta-analysis

More than one hundred studies have used the mainland Chinese version of the MATRICS Consensus Cognitive Battery (MCCB) to assess cognition in schizophrenia, but the results of these studies, the quality of the reports, and the strength of the evidence provided in the reports have not been systematically assessed. We identified 114 studies from English-language and Chinese-language databases that used the Chinese MCCB to assess cognition in combined samples of 7394 healthy controls (HC), 392 individuals with clinical high risk for psychosis (CHR-P), 4922 with first-episode schizophrenia (FES), 1549 with chronic schizophrenia (CS), and 2925 with schizophrenia of unspecified duration. The mean difference (MD) of the composite MCCB T-score (-13.72) and T-scores of each of the seven cognitive domains assessed by MCCB (-14.27 to -7.92) were significantly lower in individuals with schizophrenia than in controls. Meta-analysis identified significantly greater cognitive impairment in FES and CS than in CHR-P in six of the seven domains and significantly greater impairment in CS than FES in the reasoning and problem-solving domain (i.e., executive functioning). The only significant covariate of overall cognitive functioning in individuals with schizophrenia was a negative association with the severity of psychotic symptoms. These results confirm the construct validity of the mainland Chinese version of MCCB. However, there were significant limitations in the strength of the evidence provided about CHR-P (small pooled sample sizes) and the social cognition domain (inconsistency of results across studies), and the quality of many reports (particularly those published in Chinese) was rated 'poor' due to failure to report sample size calculations, matching procedures or methods of handling missing data. Moreover, almost all studies were cross-sectional studies limited to persons under 60 with at least nine years of education, so longitudinal studies of under-educated, older individuals with schizophrenia are needed.

Modeling psychological function in patients with schizophrenia with the PANSS: an international multi-center study

BACKGROUND

The aim of the current study was to explore the changing interrelationships among clinical variables through the stages of schizophrenia in order to assemble a comprehensive and meaningful disease model.

METHODS

Twenty-nine centers from 25 countries participated and included 2358 patients aged 37.21 ± 11.87 years with schizophrenia. Multiple linear regression analysis and visual inspection of plots were performed.

RESULTS

The results suggest that with progression stages, there are changing correlations among Positive and Negative Syndrome Scale factors at each stage and each factor correlates with all the others in that particular stage, in which this factor is dominant. This internal structure further supports the validity of an already proposed four stages model, with positive symptoms dominating the first stage, excitement/hostility the second, depression the third, and neurocognitive decline the last stage.

CONCLUSIONS

The current study investigated the mental organization and functioning in patients with schizophrenia in relation to different stages of illness progression. It revealed two distinct "cores" of schizophrenia, the "Positive" and the "Negative," while neurocognitive decline escalates during the later stages. Future research should focus on the therapeutic implications of such a model. Stopping the progress of the illness could demand to stop the succession of stages. This could be achieved not only by both halting the triggering effect of positive and negative symptoms, but also by stopping the sensitization effect on the neural pathways responsible for the development of hostility, excitement, anxiety, and depression as well as the deleterious effect on neural networks responsible for neurocognition.

Cognitive Deficits in Psychotic Disorders: A Lifespan Perspective

Individuals with disorders that include psychotic symptoms (i.e. psychotic disorders) experience broad cognitive impairments in the chronic state, indicating a dimension of abnormality associated with the experience of psychosis. These impairments negatively impact functional outcome, contributing to the disabling nature of schizophrenia, bipolar disorder, and psychotic depression. The robust and reliable nature of cognitive deficits has led researchers to explore the timing and profile of impairments, as this may elucidate different neurodevelopmental patterns in individuals who experience psychosis. Here, we review the literature on cognitive deficits across the life span of individuals with psychotic disorder and psychotic-like experiences, highlighting the dimensional nature of both psychosis and cognitive ability. We identify premorbid generalized cognitive impairment in schizophrenia that worsens throughout development, and stabilizes by the first-episode of psychosis, suggesting a neurodevelopmental course. Research in affective psychosis is less clear, with mixed evidence regarding premorbid deficits, but a fairly reliable generalized deficit at first-episode, which appears to worsen into the chronic state. In general, cognitive impairments are most severe in schizophrenia, intermediate in bipolar disorder, and the least severe in psychotic depression. In all groups, cognitive deficits are associated with poorer functional outcome. Finally, while the generalized deficit is the clearest and most reliable signal, data suggests specific deficits in verbal memory across all groups, specific processing speed impairments in schizophrenia and executive functioning impairments in bipolar disorder. Cognitive deficits are a core feature of psychotic disorders that provide a window into understanding developmental course and risk for psychosis.

Using Cognitive Neuroscience to Improve Mental Health Treatment: A Comprehensive Review

Mental health interventions do not yet offer complete, client-defined functional recovery, and novel directions in treatment research are needed to improve the efficacy of available interventions. One promising direction is the integration of social work and cognitive neuroscience methods, which provides new opportunities for clinical intervention research that will guide development of more effective mental health treatments that holistically attend to the biological, social, and environmental contributors to disability and recovery. This article reviews emerging trends in cognitive neuroscience and provides examples of how these advances can be used by social workers and allied professions to improve mental health treatment. We discuss neuroplasticity, which is the dynamic and malleable nature of the brain. We also review the use of risk and resiliency biomarkers and novel treatment targets based on neuroimaging findings to prevent disability, personalize treatment, and make interventions more targeted and effective. The potential of treatment research to contribute to neuroscience discoveries regarding brain change is considered from the experimental-medicine approach adopted by the National Institute of Mental Health. Finally, we provide resources and recommendations to facilitate the integration of cognitive neuroscience into mental health research in social work.

Dementia in schizophrenia

A growing body of evidence suggests that the most common type of dementia in schizophrenia differs from Alzheimer's disease in its clinical features, natural course, neuropathology, neuroanatomical substrates and prognosis. Furthermore, there is some evidence that the risk of developing cognitive impairment and its progression in early-onset schizophrenia differ compared with late- or very-late-onset schizophrenia. The diagnosis and management of dementia in schizophrenia is challenging for both general adult and old age psychiatrists. This article reviews the evidence base regarding dementia in schizophrenia. It discusses the diagnosis of dementia in schizophrenia, its management and prognosis, and identifies some future research opportunities.

Schizophrenia and risk of dementia: a meta-analysis study

BACKGROUND

Evidence suggests that schizophrenia may be associated with an increased risk of dementia, but results from prior studies have been inconsistent. This study aimed to estimate the relationship between schizophrenia and incident dementia using a quantitative meta-analysis.

METHODS

Several databases were used to gather relevant information, including PubMed, Embase, and Web of Science, with the publication date of articles limited up to December 23, 2017. All studies reported a multivariate-adjusted estimate, represented as relative risk (RR) with 95% confidence intervals (CIs), for the association between schizophrenia and risk of dementia incidence. Pooled RRs were calculated using a random-effects model.

RESULTS

Six studies met our inclusion criteria for this meta-analysis, which included 206,694 cases of dementia and 5,063,316 participants. All individuals were without dementia at baseline. Overall, the quantitative meta-analysis suggested that subjects with schizophrenia were associated with a significantly greater risk of dementia incidence (RR 2.29; 95% CI 1.35-3.88) than those without.

CONCLUSION

The results of this meta-analysis indicate that individuals with schizophrenia may have an increased risk for the development of dementia. Future studies should explore whether schizophrenia is a modifiable risk factor for dementia.

Higher prevalence of dementia in patients with schizophrenia: A nationwide population-based study

INTRODUCTION

This study investigates the prevalence of dementia in patients with and without schizophrenia, with a particular focus on age-specific and sex-specific differences.

METHODS

We conducted a population-based study using the National Health Insurance claims database from 2010 to 2013. Using a 10:1 matching ratio, 248,919 patients without schizophrenia and 26,591 patients with schizophrenia were identified based on the ICD-10 code. Patients with dementia were extracted by diagnosis or use of anti-dementia drugs. Conditional logistic regression analyses were performed to evaluate the association between schizophrenia and dementia.

RESULTS

The prevalence of dementia was significantly higher in schizophrenia patients compared with that in matched non-schizophrenia patients (9.9% versus 2.2%, P < 0.0001). After adjusting for Charlson comorbidity index and underlying comorbidities, conditional logistic regression showed that schizophrenia was associated with dementia (adjusted odds ratio [AOR], 4.7; 95% confidence interval [CI], 4.4-5.1). When stratified by sex, the AOR was 5.6 (95% CI, 5.0-6.2) among women and 4.0 (95% CI, 3.6-4.5) among men. Moreover, the association between dementia and schizophrenia was strong in elderly patients. The AOR of dementia prevalence was 6.6 (95% CI, 6.1-7.2) in patients aged ≥65 years and 3.4 (95% CI, 3.0-3.8) in patients aged <65 years.

DISCUSSION

Schizophrenia patients were more likely to have dementia compared with non-schizophrenia patients. This association seems greater in higher prevalence groups such as women and patients aged ≥65 years. Further investigation on the mechanism is required.

Long-term trajectories of cognitive deficits in schizophrenia: A critical overview

BACKGROUND

Cognitive disturbances are widely pronounced in schizophrenia and schizophrenia spectrum disorders. Whilst cognitive deficits are well established in the prodromal phase and are known to deteriorate at the onset of schizophrenia, there is a certain discrepancy of findings regarding the cognitive alterations over the course of the illness.

METHODS

We bring together the results of the longitudinal studies identified through PubMed which have covered more than 3 years follow-up and to reflect on the potential factors, such as sample characteristics and stage of the illness which may contribute to the various trajectories of cognitive changes.

RESULTS

A summary of recent findings comprising the changes of the cognitive functioning in schizophrenia patients along the longitudinal course of the illness is provided. The potential approaches for addressing cognition in the course of schizophrenia are discussed.

CONCLUSIONS

Given the existing controversies on the course of cognitive changes in schizophrenia, differentiated approaches specifically focusing on the peculiarities of the clinical features and changes in specific cognitive domains could shed light on the trajectories of cognitive deficits in schizophrenia and spectrum disorders.

Neurocognitive functioning of subjects with putative pre-psychotic states and early psychosis

BACKGROUND

The neurocognitive functioning of patients with schizophrenia is likely to decline at the early stage of the illness. More evidence is needed to determine whether deficits in certain domains of neurocognition precede the onset of illness and can predict the onset of psychosis.

METHODS

Subjects were recruited from the SOPRES study in Taiwan. A neuropsychological battery including the continuous performance test, Wisconsin Card Sorting Test, Wechsler Adult Intelligence Scale-Third Edition, Trail Making Tests, Mandarin version of the Verbal Fluency Test, and Wechsler Memory Scale-Third Edition, was applied at baseline and 1-year follow-up. Neurocognitive profiles derived from these tests were categorized into 9 domains for comparisons among subjects with different levels of clinical severity.

RESULTS

A total of 324 participants, including 49 with first episode psychosis (FEP), 53 with ultra-high risk (UHR), 42 with intermediate risk (IR), 43 with marginal risk (MR), and 137 normal controls completed a baseline assessment and 71% of the participants completed a 1-year follow-up assessment. The profiles of the UHR and IR groups were identical at baseline. Those who converted to FEP later on (UHR+) showed relatively poorer performance than non-converters (UHR-) at baseline. At follow-up the performance of UHR+ was compatible to that of FEP, while UHR- generally improved.

CONCLUSIONS

By including subjects with early putative pre-psychotic states, our study clarifies some inconsistencies about the timing and stability of changes in neurocognitive functioning that occur at the start of psychosis; it also raises questions regarding the feasibility of using neurocognitive deficits to predict the risks of transition to psychosis.

Neurocognition in schizophrenia: from prodrome to multi-episode illness

Individuals with schizophrenia present a neuropsychological deficit throughout the course of the disorder. Few studies have addressed the progression of the deficit since the prodromal phase of the disorder. This investigation explored neurocognition in accordance with the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus recommendations. The aim of the study was to explore the presence of neurocognitive impairment in ultra-high-risk individuals and the stage of this impairment in samples at different phases of illness. Thirty-six individuals with a prodromal syndrome, 53 first-episode and 44 multi-episode schizophrenia patients were assessed to examine neuropsychological performance. ANCOVA analysis adjusted for possible confounder factors and planned contrasts with healthy controls were undertaken. The results revealed deficits in speed-of-processing, visual-learning and social-cognition in prodromal individuals, and of all other neuropsychological domains in both first-episode and multi-episode patients. Furthermore impairment was found in the first-episode and in the multi-episode group, respectively on working-memory and attention. Within the framework of the neurodevelopmental model of schizophrenia, our results suggest the presence of neuropsychological impairment before the onset of full-blown psychosis. Moreover, the deficits are larger in the more chronic groups, according to the theory of an ongoing neurodevelopmental alteration.

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.

Comparing neurocognition in severe chronic schizophrenia and frontotemporal dementia

OBJECTIVE

Previous research has suggested cognitive similarities between schizophrenia and frontotemporal dementia. In the current study, we compared neurocognition in a group of hospitalised patients with chronic schizophrenia, who may have a more severe form of schizophrenia resembling Emil Kraepelin's dementia praecox, with patients with frontotemporal dementia. We hypothesised minimal group differences in cognitive performance, and a large overlap in between-group score distributions in each cognitive domain.

METHODS

Retrospective neuropsychological data for 26 patients with severe chronic schizophrenia and 34 patients with frontotemporal dementia (behavioural variant) was collated. Neuropsychological measures were categorised into 16 cognitive domains. Raw scores were converted into standardised z-scores for each measure, which were then averaged across measures within each domain. In addition to difference analysis, equivalence testing was utilised, whereby overlap percentages were computed to reflect the amount of score distribution overlap in each domain between groups.

RESULTS

A statistically significant difference was observed only in the executive function sub-domain of Switching. Small-to-moderate and moderate effect sizes were noted in four other domains. Equivalence testing showed more than 85% of overlap in score distribution in most domains.

CONCLUSIONS

Our findings suggest that some patients with severe chronic schizophrenia have cognitive deficits similar in degree and pattern to patients with frontotemporal dementia. The few differences observed between both groups of patients are important for differential diagnostic purposes. One limitation is the retrospective nature of the study. Suggestions for future research include longitudinal follow-up studies of these two patient populations and studies of aspects beyond neurocognition. An implication of our findings is that the 'dementia of schizophrenia' concept may be applicable to patients with severe chronic schizophrenia.

Cognitive decline and dementia risk in older adults with psychotic symptoms: a prospective cohort study

OBJECTIVES

To study the temporal association between psychotic symptoms with cognitive decline and incident dementia.

DESIGN

Population-based prospective cohort study.

SETTING

General population in England and Wales.

PARTICIPANTS

A subsample of 2,025 participants of the Medical Research Council Cognitive Function and Ageing Study, representing a study sample of 11,916 nondemented adults age 65 years or older.

MEASUREMENTS

Baseline presence of psychotic symptoms was assessed with the Geriatric Mental State. Cognitive decline (Cambridge Cognitive Examination) and incident dementia (Automated Geriatric Examination for Computer Assisted Taxonomy diagnosis) were evaluated at 2, 6, and 10 years from baseline.

RESULTS

A total of 330 participants reported baseline symptoms of paranoid delusions, misidentification, or hallucinations, estimated to represent 13.4% of the older general population without dementia. Psychotic symptoms were cross-sectionally associated with worse cognitive functioning, and individuals with psychotic symptoms displayed more rapid cognitive decline from baseline to a 6-year follow-up, especially in nonmemory functions, than people without such symptoms. They further carried an increased overall risk of later dementia (odds ratio = 2.76, 95% confidence interval = 1.75-4.36). The risk increment was observed independently of baseline cognition, depression, anxiety, and vascular risk factors, increased with increasing numbers of psychotic symptoms, and was highest in people age 65-74 years.

CONCLUSIONS

Older adults with psychotic symptoms are vulnerable to develop dementia and might be a promising target for indicated prevention strategies. Their neuropsychological functioning should be evaluated on a regular basis.

Is there evidence for late cognitive decline in chronic schizophrenia?

Schizophrenia (SZP) has been historically referred to as "dementia praecox" because of the recognition that its onset is associated with deficits in memory, attention and visuospatial orientation. We wondered whether there is evidence for additional cognitive decline late in the course of chronic SZP. This review examined the evidence (1) for cognitive decline late in the course of chronic SZP, (2) for how often the late cognitive decline occurs, and (3) whether the cognitive decline in late-life SZP is related to pathophysiology of SZP versus the superimposition of another type of dementia. A PUBMED search was performed combining the MESH terms schizophrenia and dementia, cognitive decline, cognitive impairment and cognitive deficits. A manual search of article bibliographies was also performed. We included longitudinal clinical studies employing standard tests of cognition. Cross-sectional studies and those that did not test cognition through standard cognitive tests were excluded. The initial search produced 3898 studies. Employing selection criteria yielded twenty-three studies. Our data extraction tool included the number of patients in the study, whether a control group was present, the age of patients at baseline and follow-up, the study setting (inpatients versus outpatients), the cognitive tests employed, study duration, and results. Only three longitudinal studies tested for dementia using Diagnostic and statistical manual of mental disorder (DSM) or International classification of disease (ICD) criteria and compared them to controls: two studies demonstrated an increase in the prevalence of dementia and one did not. Twenty longitudinal studies tested for one or more cognitive domains without employing standard criteria for dementia: twelve studies demonstrated a heterogeneous pattern of cognitive decline and eight did not. Studies generally did not control for known risk factors for cognitive impairment such as education, vascular risk factors, apolipoprotein (ApoE) genotype and family history. The evidence for late cognitive decline in SZP is mixed, but, slightly more studies suggest that it occurs. If it occurs, it is unclear whether it is related to SZP or other risks for cognitive impairment. Hence, prospective, longitudinal, controlled studies are needed to confirm that there is progressive cognitive decline in chronic SZP which occurs independent of other risk factors for cognitive impairment.

Neuropsychological performance in older patients with schizophrenia: a meta-analysis of cross-sectional and longitudinal studies

OBJECTIVE

Cognitive deficits are among the most reliable predictors of functional impairment in schizophrenia and a particular concern for older individuals with schizophrenia. Previous reviews have focused on the nature and course of cognitive impairments in younger cohorts, but a quantitative meta-analysis in older patients is pending.

METHOD

A previously used search strategy identified studies assessing performance on tests of global cognition and specific neuropsychological domains in older patients with schizophrenia and age-matched comparison groups. Both cross-sectional and longitudinal studies were included. Potential methodological, demographic, and clinical moderators were analyzed.

RESULTS

Twenty-nine cross-sectional (2110 patients, 1738 comparison subjects) and 14 longitudinal (954 patients) studies met inclusion criteria. Patients were approximately 65 years old, with 11 years of education, 53% male and 79% Caucasian. Longitudinal analysis (range 1-6 years) revealed homogeneity with small effect sizes (d = -0.097) being observed. Cross-sectional analyses revealed large and heterogeneous deficits in global cognition (d = -1.19) and on specific neuropsychological tests (d = -0.7 to -1.14). Moderator analysis revealed a significant role for demographic (age, sex, education, race) and clinical factors (diagnosis, inpatient status, age of onset, duration of illness, positive and negative symptomology). Medication status (medicated vs nonmedicated) and chlorpromazine equivalents were inconsequential, albeit underrepresented.

CONCLUSIONS

Large and generalized cognitive deficits in older individuals with schizophrenia represent a robust finding paralleling impairments across the life span, but these deficits do not decline over a 1-6 year period. The importance of considering demographic and clinical moderators in cross-sectional analyses is highlighted.

Visual P3 amplitude modulation deficit in schizophrenia is independent of duration of illness

BACKGROUND

In the search for markers of schizophrenia, functional deficits during inhibition have been a major focus. In previous studies, we found a reduced amplitude modulation of the visual P3 component of the event-related potential (ERP) in schizophrenic patients during inhibition in the Attention Network Test (ANT). The objective of the present study was to explore whether this deficit exhibits properties of a trait or state marker of schizophrenia.

METHODS

Eighteen recent onset inpatients and eighteen chronic schizophrenic outpatients as well as 36 healthy controls, including a young adult and an old adult group to match recent onset and chronic illness groups for age and sex, were included. Participants were tested with ANT while 32-channel electroencephalogram was recorded and visual P3 amplitudes were analyzed. Amplitude modulation was defined as the variation of P3 amplitude at Pz as a function of ANT flanker conditions.

RESULTS

There were no significant behavioral between-group differences in terms of alerting, orienting, and inhibition. Mean visual P3 was significantly lower in schizophrenic patients than in healthy controls. Parietal P3 amplitude was significantly less modulated in both recent onset (-0.035) and chronic schizophrenic patients (-0.081) compared with young (-0.588; p<0.05) and older healthy controls, respectively (-0.556; p<0.05). No correlations were obtained between P3 modulation and clinical or demographic variables.

CONCLUSION

The results provide evidence that the observed deficit of visual P3 amplitude modulation is independent of duration of illness and age and may contain properties of a trait marker of schizophrenia.

Evolution of neuropsychological dysfunction during the course of schizophrenia and bipolar disorder

BACKGROUND

Neurocognitive dysfunction in schizophrenia (SZ), bipolar (BD) and related disorders represents a core feature of these illnesses, possibly a marker of underlying pathophysiology. Substantial overlap in domains of neuropsychological deficits has been reported among these disorders after illness onset. However, it is unclear whether deficits follow the same longitudinal pre- and post-morbid course across diagnoses. We examine evidence for neurocognitive dysfunction as a core feature of all idiopathic psychotic illnesses, and trace its evolution from pre-morbid and prodromal states through the emergence of overt psychosis and into chronic illness in patients with SZ, BD and related disorders.

METHOD

Articles reporting on neuropsychological functioning in patients with SZ, BD and related disorders before and after illness onset were reviewed. Given the vast literature on these topics and the present focus on cross-diagnostic comparisons, priority was given to primary data papers that assessed cross-diagnostic samples and recent meta-analyses.

RESULTS

Patients with SZ exhibit dysfunction preceding the onset of illness, which becomes more pronounced in the prodrome and early years following diagnosis, then settles into a stable pattern. Patients with BD generally exhibit typical cognitive development pre-morbidly, but demonstrate deficits by first episode that are amplified with worsening symptoms and exacerbations.

CONCLUSIONS

Neuropsychological deficits represent a core feature of SZ and BD; however, their onset and progression differ between diagnostic groups. A lifetime perspective on the evolution of neurocognitive deficits in SZ and BD reveals distinct patterns, and may provide a useful guide to the examination of the pathophysiological processes underpinning these functions across disorders.

Clinical outcomes and low-dose levocarnitine supplementation in psychiatric inpatients with documented hypocarnitinemia: a retrospective chart review

BACKGROUND

Metabolic encephalopathy is one of the crucial manifestations of carnitine deficiency. In psychiatric patients, low serum carnitine levels may result from chronic valproate therapy. Despite the widespread use of valproate in psychiatry, neither carnitine deficiency nor supplementation has been studied in a psychiatric population.

OBJECTIVE

To describe clinical outcomes in hospitalized psychiatric patients with documented hypocarnitinemia who were receiving oral levocarnitine supplementation.

METHOD

Retrospective chart review.

RESULTS

In 38 patients with hypocarnitinemia, a low-dose oral levocarnitine supplementation, in association with comprehensive psychiatric therapy, did not result in any adverse psychiatric or medical outcomes, and was associated with overall improved behavioral, cognitive, and motor functioning. Initially all patients had some degree of cognitive impairment, but after correction of carnitine serum levels, scores on the Mini-Mental State Examination (MMSE) improved in most of the patients (mean improvement 5.5 points, P <0.0001), and normalized in 11 cases. This allowed a correction of the diagnosis in 8 of 14 patients who had initially been diagnosed with dementia. African-American patients achieved significantly lower serum carnitine levels and MMSE scores than Caucasian patients with comparable therapy.

CONCLUSION

We hypothesize that correction of carnitine depletion, either by levocarnitine supplementation or by valproate dose reduction, may enhance recovery from hypocarnitinemia-associated encephalopathy in psychiatric patients. Our findings also suggest that ethnic traits may affect carnitine bioavailability as well as cognitive outcomes in this clinical context. Further studies of carnitine metabolism and supplementation in psychiatric patients are warranted.

Clinical differences between late-onset and early-onset chronically hospitalized elderly schizophrenic patients in Taiwan

OBJECTIVES

To examine the clinical differences between late-onset schizophrenia (LOS) and early-onset schizophrenia (EOS) in Taiwanese elderly chronic hospitalized schizophrenic patients.

METHODS

By using a cross-sectional study method, we investigated all the hospitalized elderly schizophrenic patients in a general hospital's psychiatric ward during July-September 2007. All the subjects matched DSM-IV-TR diagnostic criteria and were aged 60 years or above. A total of 52 subjects were enrolled (LOS = 23, EOS = 29). Demographic data, illness history, and antipsychotic treatment record were documented; the positive and negative syndrome scale (PANSS), Center for Epidemiological Studies Depression scale (CES-D), mini-mental status examination (MMSE), activities of daily living rating scale for psychiatric patients (ADLRS), community self-sufficiency test (CST), clinical global impression (CGI), and general assessment of functioning scale (GAF) were administered.

RESULTS

In our samples, a lower educational level was found to be more common in late-onset patients. In LOS, there was no significant increase in the severity of PANSS psychopathology except for greater thought disorder symptoms. Both LOS and EOS patients had similar cognitive and functioning impairment with poor global outcomes. There was a trend of low antipsychotic drug use in LOS.

CONCLUSIONS

In Taiwan, elderly chronic inpatients LOS had greater thought disorders compared to findings in Western studies. Further large-scale longitudinal studies are needed to understand the factors related to these findings.

Duration of Illness, Regional Brain Morphology and Neurocognitive Correlates in Schizophrenia

Introduction: Previous studies examining brain effects of duration of illness in schizophrenia have focused on either cortical or subcortical structures. Hence this study sought to elucidate the regional grey matter changes (both cortical and subcortical) and neurocognitive correlates with increased duration of illness in a large sample of patients with schizophrenia using voxel-based morphometry. Materials and Methods: Ninety patients (72 males and 18 females) with DSM-IV diagnosis of schizophrenia were recruited and assessed using magnetic resonance imaging and a battery of neuropsychological tests. Results: A longer duration of illness was associated with smaller grey matter volumes in the left superior frontal gyrus, bilateral putamen, right superior temporal gyrus, right superior occipital gyrus as well as the right thalamus. No region showed increased grey matter volume above threshold with longer duration of illness. Longer duration of illness was correlated with poorer attention. Conclusions: The grey matter reductions in different brain regions highlighted that a distributed network of cortical and subcortical regions was associated with duration of illness. This is consistent with neural models that implicate involvement of thalamo-cortical circuitry as the disruption in these neural pathways can result in specific deficits such as poorer attention. The results have implications for the understanding of brain changes in schizophrenia, and with further studies, may guide better tailored and targeted clinical management in terms of reducing the impact of duration of illness on neural substrates in schizophrenia in the future. Key words: Duration of Illness, Grey Matter, Magnetic resonance imaging, Voxel-based Morphometry

1-year follow-up study of cognitive function in first-episode non-affective psychosis

The longitudinal course of primary cognitive dysfunction seen in schizophrenia has yet to be fully clarified. Whereas some studies in chronic patients have revealed a progressive decline in cognitive abilities, those studies with first-episode patients have indicated that initial cognitive deficits might remain stable over time. The aim of this study was to examine the longitudinal course of cognitive functioning in patients with a first episode of schizophrenia. 112 patients with a first episode of schizophrenia-spectrum disorders and 22 healthy controls completed clinical and cognitive evaluations at baseline and again after 1 year. An extensive neuropsychological battery that comprised seven cognitive domains was used. Patients and controls improved their cognitive performance in virtually all the cognitive domains after one year. However, patients continued to show marked cognitive deficits after one year, unlike healthy volunteers. The longitudinal cognitive changes were similar in patients and controls in all domains except Verbal Memory (F = 11.67; df = 1; P = 0.001). The increase in cognitive scores found during early phases of the illness seems to be associated to practice-related changes and would not reflect a real cognitive enhancement but rather stability of deficit. Patients' deficits remained stable over time in all cognitive domains except Verbal Memory, in which less performance improvement was found. Further investigations are warranted to discern the variability in patterns of specific cognitive deficits over time.

A review of the effects of modafinil on cognition in schizophrenia

Modafinil, a wake-promoting agent believed to operate via the hypocretin/orexin system, has a similar clinical profile to that of conventional, dopaminergic stimulants but different biochemical and pharmacological properties. There is increasing interest in the use of modafinil to improve cognition in schizophrenia as well as in other disorders such as attention-deficit/hyperactivity disorder. Recent research has focused on enhancing cognition in patients with schizophrenia because of the association between cognitive performance and functional outcome. Initial findings indicate that modafinil may lead to better executive functioning and attentional performance in patients with schizophrenia. The results further suggest that patient characteristics such as overall current cognitive functioning levels, genetic polymorphisms, and medication status may be important mediators for the effectiveness of modafinil, allowing for future treatment to be targeted to those most likely to benefit. Currently, further research is required to address the potential benefits and risks of chronic administration of modafinil to patients with schizophrenia.

Cortical activation during two verbal fluency tasks in schizophrenic patients and healthy controls as assessed by multi-channel near-infrared spectroscopy

Near-infrared spectroscopy (NIRS) is an optical imaging method that allows non-invasive in-vivo measurements of changes in the concentration of oxygenated (O(2)Hb) and deoxygenated (HHb) hemoglobin in brain tissue. For the present study, we examined 12 schizophrenic patients and 12 age- and gender-matched healthy controls by means of multi-channel NIRS (Optical Topography; ETG-100, Hitachi Medical Co., Japan) during performance of two versions of the Verbal Fluency Test (VFT; letter and category version). The results indicate that the verbal fluency tasks generally led to clear frontal activation in healthy controls, which was significantly reduced in schizophrenic patients. The letter version of the VFT induced overall stronger activation than the category version, the group difference being particularly pronounced for phonological fluency. Moreover, significant positive correlations between task-related activation effects in prefrontal and temporal NIRS channels were found in both schizophrenic patients and healthy controls. The results confirm functional deficits within the frontal lobe in patients suffering from schizophrenic illnesses, but do not confirm previous findings on abnormal fronto-temporal correlations or increased temporal activation in this group of patients. The data furthermore underline the usefulness of functional NIRS in monitoring hemodynamic responses associated with cognitive processes in healthy controls and patients with neuro-psychiatric disorders.

Anticholinergic use in hospitalised schizophrenic patients in Belgium

This naturalistic study aims to evaluate the influence of antipsychotic treatment on the use of anticholinergics. The observed use of anticholinergics will give an indication of the occurrence of extrapyramidal side effects (EPS) in the different antipsychotic treatment conditions. The medication use of 1215 hospitalised patients with DSM-IV 295.xx diagnosis is recorded. Four antipsychotic treatment conditions are distinguished: 1) only first generation antipsychotics (FGA): patients receive one or a combination of first generation antipsychotics, 2) a combination of high potency FGA and second generation antipsychotics (SGA), 3) a combination of low potency FGA and SGA, and 4) only SGA: patients receive one or a combination of SGA. Antipsychotic treatment significantly influences the use of anticholinergics. Anticholinergic use is highest in patients treated with high potency FGA (whether or not in combination with SGA) as compared with patients only treated with SGA and patients combining SGA with low potency FGA. The two latter groups do not significantly differ. However, there were no significant differences in the prevalence of EPS with the exception of akathisia between FGA and SGA. Thus, through the use of anticholinergics, EPS induced by FGA can be effectively reduced.

Improvement of prefrontal brain function in endogenous psychoses under atypical antipsychotic treatment

Typical and atypical antipsychotics are thought to exert their effects on different neurotransmitter pathways with specific action of atypical compounds on the prefrontal cortex, but studies directly investigating the effect of those drugs on neurophysiological measures of prefrontal brain function are sparse. We therefore investigated the influence of different antipsychotics on an electrophysiological marker of prefrontal brain function (NoGo anteriorization, NGA) and neuropsychological test scores. For this purpose, 38 patients with endogenous psychoses were investigated at the beginning of a stationary psychiatric treatment and at a 6-week-follow-up. Patients were treated with typical or atypical antipsychotics, or a combination of both. They underwent psychopathological diagnostic and neuropsychological testing, as well as electrophysiological investigations during a Continuous Performance Test. The results indicate that typical and atypical antipsychotics differentially affected the development of the NGA over the course of the treatment, typical antipsychotics tending to result in decreased values at follow-up, and atypical antipsychotics stabilizing, or increasing this parameter. Performance in tests of frontal lobe function generally declined under typical antipsychotics and improved with atypical compounds, changes in Stroop interference correlated with changes in the NGA. We conclude that typical and atypical antipsychotics differ regarding their effect on prefrontal brain function in schizophrenia, atypical neuroleptics often showing a more favorable impact than conventional antipsychotics on respective parameters.

Intellectual Decline in Schizophrenia: Evidence from a Prospective Birth Cohort 28 Year Follow-up Study

It is well established that IQ is lower among persons with schizophrenia than in the general population. However, it remains unclear if there is deterioration beyond a premorbid deficit. In order to assess the question of IQ deterioration, we assessed persons pre- and-post psychosis, comparing those who developed schizophrenia with those who did not. Twenty six patients with schizophrenia and 59 normal controls, evaluated at age 7 in the prospective, longitudinal, National Collaborative Perinatal Project (NCPP), were re-tested approximately 28 years later. We assessed change in an estimate of IQ based on the Vocabulary and Block Design tests from the Wechsler intelligence scales. Persons who later developed schizophrenia were significantly impaired on IQ compared to controls at age 7, especially on measures of attention. At age 35, persons with schizophrenia demonstrated significant impairment and deterioration on both IQ sub-tests compared to controls. Because impairment occurs by early childhood and subsequent deterioration occurs at an unknown period, designs with more frequent assessment of IQ through the premorbid, prodromal and early phases of illness are required to identify the key period of decline. Future research on this sample will evaluate the prospective roles of family history and perinatal complications on cognition, and assess the specificity of these findings.

Patterns and clinical correlates of neuropsychologic deficits in patients with schizophrenia

BACKGROUND/PURPOSE

Neuropsychologic deficits are prevalent among schizophrenic patients and are closely associated with pathogenesis and outcome. The pattern, extent, severity and contributing factors to such deficits remain to be examined in Taiwanese schizophrenic patients.

METHODS

A total of 122 schizophrenic patients and 94 healthy subjects for comparison were assessed by a comprehensive neuropsychologic test battery covering the eight cognitive domains of verbal ability, visual spatial ability, abstraction/execution, verbal memory, visual memory, perceptual/motor ability, mental control and attention. The relationships among cognitive deficits, demographic characteristics, clinical historical variables and clinical symptoms were further explored by multivariate regression analysis.

RESULTS

A pattern of selective deficits superimposed on a generalized deficit was found for schizophrenic patients as a group. The mean overall deficit was 1.93 standard deviations below the control mean, and abstraction/execution, verbal memory, visual memory and attention were relatively impaired among the eight cognitive domains. However, there was also marked heterogeneity in individual performances in that 24.2%, 46.2% and 29.5% of patients performed at within normal range, moderately impaired and severely impaired levels, respectively. Duration of illness substantially affected the profile and severity of the deficits, suggesting a progressive deteriorating course in neuropsychological performance. The major predictors of cognitive deficits were number of formal years of education achieved and concurrent severity of disorganization symptoms.

CONCLUSION

In a large sample of schizophrenic patients who underwent comprehensive neuropsychologic evaluation, the current results confirmed that cognitive deficits were prevalent but not a universal feature within schizophrenia. The selective impairment pattern also confirmed that such deficits were mainly in frontal and frontotemporal related functions. Despite evidence suggesting that disease chronicity entailed a decline in selective cognitive domains, the trajectory of the neuropsychologic deficits remains to be examined by further longitudinal studies.

Endophenotypes for psychiatric disorders: ready for primetime?

It is increasingly accepted that the imprecision of categorical psychiatric diagnoses can be a limiting factor in understanding the genetic basis of human behavioral abnormalities. Genetic investigation of endophenotypes--more precisely defined quantitative traits hypothesized to underlie disease syndromes--offers great promise as an alternative or complement to studies of categorical disease phenotypes. However, there is not yet standardization of the methods by which candidate endophenotypes should be chosen and applied. Fruitful endophenotype studies depend on the selection of heritable, quantitative traits that can be objectively and reliably measured. In this article, we propose guidelines for such investigations for psychiatric disorders, using endophenotypes previously proposed for bipolar disorder as particular examples. Gene expression studies and non-human primate models are recent developments in which an endophenotype approach might prove particularly valuable.

Neonatal lesions of the ventral hippocampus in rats lead to prefrontal cognitive deficits at two maturational stages

This experiment assessed the effect of neonatal ventral hippocampus lesions in rats, a heuristic approach to model schizophrenia, on continuous delayed alternation and conditional discrimination learning performance before and after complete cerebral maturation. Delays (0, 5, 15, and 30 s) were introduced in the tasks to help dissociate between a hippocampal and a prefrontal cortex dysfunction. At postnatal day (PND) 6 or 7, rats received bilateral microinjections of ibotenic acid or phosphate-buffered saline in the ventral hippocampus. From PND 26 to PND 35, rats were tested on the alternation task in a T-maze; from PND 47 to PND 85, the same rats were tested in the discrimination task where a stimulus and a response location had to be paired. Deficits in ventral hippocampus-lesioned rats were observed in both tasks whether a delay was introduced before a response or not. Impaired performance regardless of delay length, combined with high rates of perseverative errors, suggested a post-lesional prefrontal cortex dysfunction which persisted from the juvenile stage into adulthood. Premature cognitive impairments could not be predicted on the basis of the neurodevelopmental animal model of schizophrenia. Nevertheless, they appear consistent with accounts of premorbidly compromised memory, both immediate and delayed, in subgroups of schizophrenia patients.

Cognitive heterogeneity in first-episode schizophrenia

BACKGROUND

Studies of chronic schizophrenia suggest that there are subgroups with different profiles of cognitive impairment.

AIMS

To determine whether such heterogeneity is present at illness onset and any relationship to clinical variables.

METHOD

Ninety-three community patients with first-episode schizophrenia and 50 healthy volunteers were assessed for premorbid (Revised National Adult Reading Test) and current IQ, memory and executive function.

RESULTS

Half of those with schizophrenia had preserved IQ in the normal range but there was evidence of a specific impairment in spatial working memory even in those with high/average IQ; 37 out of 93 (40%) had generalised cognitive decline. Those with low premorbid IQ were significantly younger at illness onset. For the entire group, age at onset correlated positively with premorbid but not current IQ.

CONCLUSIONS

At illness onset, cognitive heterogeneity is present in people with schizophrenia, with a high proportion having undergone general cognitive decline. However, working memory impairment may be a common feature. Lower premorbid IQ is a risk factor for an earlier onset.

Older people with chronic schizophrenia

Older people with chronic schizophrenia are a numerically small but important group with complex clinical and service needs. Along with a reduction in positive schizophrenic symptoms with increasing age, a majority suffer from negative symptoms, cognitive deficits, depression, side effects due to long-term use of antipsychotics and co-morbid medical problems. They may have social disabilities making them vulnerable to poverty, isolation and poor quality of life. Evidence suggests that judicious use of antipsychotics combined with psychotherapy and psychosocial interventions are effective. There are shortcomings in the standard of both hospital and community care, and the cost implications of providing adequate services are high.

Verbal fluency in institutionalized patients with schizophrenia: age-related performance decline

Several studies have reported a relatively stable level of cognitive deficits among patients with schizophrenia regardless of age, while others have suggested continued deterioration with age. We compared the performance of 42 institutionalized patients with schizophrenia and 42 age- and education-matched healthy controls on a semantic and phonemic verbal fluency test. Each group was divided into young participants (<65 years old) and elderly participants (> or =65 years old). We found a fluency condition x diagnostic group x age group interaction on total words produced, a fluency condition x diagnostic group interaction on the number of cluster-related words, and a fluency condition x age group interaction on the number of switches. Patients with schizophrenia generally used similar strategies (i.e., semantic or phonemic cluster-related words and switches) as healthy individuals when generating words, but to a lesser degree. We found a disproportionate decline in the elderly schizophrenic patients relative to that of healthy controls only on the phonemic, relative to the semantic test. This decline in performance appears related to the effects of aging rather than severity or chronicity of illness, duration of institutionalization, or a progressive degenerative process associated with the disorder.

Neuropsychological subtyping of schizophrenia

Schizophrenia tends to be associated with a general decline in cognitive functioning. However, some studies have found neuropsychologically normal schizophrenia patients. To address this contradiction, we screened first-episode schizophrenic patients according to degree of neuropsychological dysfunction. At least three different neuropsychological subtypes of schizophrenia were found. Memory, specifically delayed recall, was the most important factor that discriminated the groups. Neuropsychological assessment, covering a range of functional domains of the major dimensions of behavior, has an important role in identifying preserved and impaired capacities, in predicting outcome, and in planning treatment.

Secondary verbal memory: a potential endophenotype of schizophrenia

This study aimed at identifying neuropsychological endophenotypes of schizophrenia which met the criteria of stability and sensitivity. Twenty-six non-schizophrenic first-degree relatives together with their affected family members (all simplex-families) underwent assessment with a comprehensive neuropsychological test battery both at baseline and 13 months follow-up. Follow-up patients were in a state of stable remission. Further, 21 unrelated, demographically balanced, non-vulnerable controls were tested one at a time. A principal components analysis of our test battery resulted in four factors: (1) Vigilance, attention, and psychomotor, (2) secondary verbal memory, (3) immediate and working memory, and (3) abstraction and problem solving. At baseline testing our study revealed a pattern of selective cognitive deficits in the relative group that is less pronounced, yet qualitatively similar, to that found in the patient sample. The most severe deficits displayed both the patients and their relatives in the secondary verbal memory domain. The dysfunctions in secondary verbal memory at baseline testing significantly correlated with negative symptoms only. Secondary verbal memory deficits proved to be relatively independent of age at onset of illness, illness duration, and neuroleptic dosage. Longitudinally, dysfunctions in the patients' secondary verbal memory fluctuated over time and with negative symptoms, and persisted in remitted patients at the same level as in their relatives. In conclusion, the secondary verbal memory met the criteria of relative stability and sensitivity in our sample of simplex-families. Thus, the secondary verbal memory seems to be a potential endophenotypic marker of schizophrenia, even for cases with a hypothetically lower genetic loading.

Relationship between psychopathology and cognitive functioning in schizophrenia

The purpose of this study was to delineate the relationship between positive, negative, cognitive, depressive, and excitement symptom dimensions of schizophrenia and cognitive functioning. Fifty-eight patients with schizophrenia (DSM-IV criteria) were assessed using the Positive and Negative Syndrome Scale (PANSS) and a battery of neuropsychological tests (executive function/abstraction, verbal and spatial working memory, verbal and nonverbal memory/learning, attention, visuospatial ability, and psychomotor speed). The cognitive symptom dimension correlated with executive functions, attention, verbal memory, and spatial ability. Severity of the negative symptom dimension was related to impairment in the structure of the semantic knowledge system, verbal memory, and auditory attention. In contrast, severity of the positive symptom dimension correlated only with impairment in the structure of the semantic knowledge system, and psychomotor speed. Finally, severity of the depressive and excitement symptom dimension was not associated with cognition. Correlations between symptom dimensions and cognitive measures were at best modest. Severity of cognitive and negative symptoms was mainly correlated with deficits on executive functions, semantic memory, and verbal memory, while positive symptoms only with semantic memory. These correlations were modest, suggesting that psychopathology and cognitive deficits in schizophrenia are caused, at least partially, by distinct pathophysiological processes.

Long-term memory deficits in schizophrenia: primary or secondary dysfunction?

Long-term memory impairment is often found in schizophrenia. The question remains whether this is caused by other cognitive deficits. One hundred eighteen first-episode patients were compared with 45 control participants on several memory tasks. The role of processing speed and central executive functions on memory performance was examined with regression analysis for all participants and for patients separately. Deficits were found in general verbal learning performance and retrieval in episodic memory and semantic memory. Processing speed reduced disease-related variance in all memory variables. Coordination, organization of information, and speed of processing were the best predictors for long-term memory deficits in patients. The amount of explained variance, however, is small, especially in general verbal learning performance.

Clock Drawing Test in patients with schizophrenia

Investigations of the usefulness of the Clock Drawing Test (CDT) in schizophrenia have focused primarily on institutionalized or elderly patients. The purpose of the present study was to compare CDT performance of patients with schizophrenia living in the community with that of normal controls. Fifty-three patients with schizophrenia were compared with 66 age- and gender-matched normal controls. The CDT ('free-drawn', 'pre-drawn' and three 'examiner' conditions) and the Mini-Mental State Examination (MMSE) were administered to all participants. In patients with schizophrenia, symptom severity was assessed with the Positive and Negative Syndrome Scale (PANSS). Patients with schizophrenia had significantly lower scores on the MMSE and the five CDT conditions than the control group. When MMSE scores and level of education were included in the comparisons as covariates, the differences between the two groups remained significant. MMSE scores of the patients with schizophrenia correlated significantly with four clock conditions: 'free-drawn' 'pre-drawn' and two of the 'examiner' conditions (11:10 and 8:20). Poorer performance on the CDT correlated with higher scores on the PANSS positive symptoms subscale. Qualitative analysis of the clocks that were drawn revealed specific errors in the schizophrenia group relating to frontal processes: difficulty placing numbers in the correct position, failure to indicate the minute targets, displacement of the minute hand from the minute number, and failure to draw a longer minute hand. The fact that the CDT is sensitive enough to detect the cognitive impairment inherent in schizophrenia, as well as being correlated with symptom severity, makes this test useful in roughly assessing cognitive state in schizophrenia.

Long-term outcome of late-onset schizophrenia: 5-year follow-up study

BACKGROUND

There is controversy about whether late-onset schizophrenia is a precursor of cognitive decline.

AIMS

To examine the long-term outcome of a group of patients with late-onset schizophrenia.

METHOD

Patients with onset of DSM-III-R schizophrenia at age 50 years or over, but without dementia, and a healthy control group were assessed at baseline (n=27 and n=34, respectively), after 1 year and after 5 years (n=19 and n=24, respectively) on measures of psychopathology, cognition and general functioning, and compared on rates of decline and incidence of dementia.

RESULTS

Nine patients with late-onset schizophrenia and none of the control group were found to have dementia (5 Alzheimer type, 1 vascular, 3 dementia of unknown type) at 5-year follow-up. There appeared to be a subgroup of late-onset schizophrenia patients without signs of dementia at baseline or at 1 year follow-up who subsequently declined.

CONCLUSIONS

Late-onset schizophrenia may be a prodrome of Alzheimer-type dementia. More longitudinal studies are required to determine its nosological status.

Right-hemisphere encephalopathy in elderly subjects with schizophrenia: evidence from neuropsychological and brain imaging studies

RATIONALE

Cognitive impairment is a recognised feature of schizophrenia. Elderly patients with early-acquired schizophrenia are seriously affected, with a proportion of them showing clinically significant dementia, not accounted for by any recognized degenerative processes common in this age group, such as Alzheimer's disease. Progression of cognitive deficits is described in elderly institutionalised patients, but disputed amongst community dwelling subjects. The pattern of cognitive deficits in this age group is not yet clearly defined, although there is some evidence that it differs from that in Alzheimer's disease. There is little evidence of any underlying specific brain abnormality.

OBJECTIVES

To characterize the neuropsychological deficits in elderly schizophrenia patients and distinguish them from those in Alzheimer's disease. To establish the presence of underlying structural brain abnormality using MRI.

METHODS

Twenty-eight elderly schizophrenia patients with onset before the age of 45 years carried out neuropsychology tests. Twelve scored in the dementia range and were compared with 16 equally impaired patients with early Alzheimer's disease. Thirteen of the schizophrenia patients consented to brain MRI. The imaging data were analysed using a newly developed automated method of measuring CSF volume distributions and compared with data from 30 age-matched normal controls.

RESULTS

The schizophrenia group was more impaired on visuo-spatial tasks than the Alzheimer's group but less impaired on corresponding verbal tasks, despite similar overall cognitive impairment. The MR scans revealed right-sided enlargement of ventral CSF spaces in the schizophrenia patients especially in the posterior third, and this correlated with their impaired performance on visuo-spatial tasks.

CONCLUSIONS

The results suggest that right hemisphere impairment underlies the specific profile of cognitive impairment in elderly patients with schizophrenia.

Changes in cognitive functioning following comprehensive treatment for first episode patients with schizophrenia spectrum disorders

The course of cognitive functioning over a 1-year period was examined among a community cohort of individuals presenting with first episode schizophrenia spectrum psychosis. Data were obtained for 83 outpatients at entry to an early intervention program and 12 months later on the National Adult Reading Test, Wechsler Adult Intelligence Scales-Third Edition, Wechsler Memory Scales-Third Edition, Paced Auditory Serial Addition Task, Wisconsin Card Sorting Test, Stroop Colour and Word Test, Trail Making Test, Continuous Performance Task and Thurstone Word Fluency Test. Paired sample t-tests indicated significant and positive changes in verbal and non-verbal intelligence, auditory and visual memory, working memory and some aspects of executive functioning. Processing speed also improved though remained an area of relative weakness for this sample. Findings indicated generally average performance at both assessment periods. Neither gender nor duration of untreated psychosis were related to the degree of change in cognitive functioning for this sample. The implications of these findings and the impact of early intervention with this population are discussed.

Arguments against the cognitive dysmetria hypothesis of schizophrenia

Recently, the 'cognitive dysmetria' theory for schizophrenia has been formulated. According to this theory, a primary neurocognitive dysfunction is the core of schizophrenia and underlies symptom formation. The suggested perceptual fragmentation of external stimuli and inability to connect such perceptions with internal schemata is suggested to lead to positive symptoms, while defensive self-restriction and the exhaustion of the mental apparatus lead to negative symptomatology. Objections to this theory include observations (i) that patients with dominant positive symptoms, e.g., delusions, hallucinations, manifest better neurocognitive function and (ii) that typically antipsychotics significantly reduce positive symptoms and thus improve both the clinical picture and the functioning (to the extent it is reduced with positive symptoms) of the patients, yet have little or no effect on negative, e.g., loss of volition, emotional blunting, and neurocognitive symptomatology, e.g., attentional and memory deficit. The literature suggests that neurocognitive symptoms group independently of other symptomatology. It is suggested that there is currently more evidence against than in favor of the 'cognitive dysmetria' theory.

Dementia as a complication of schizophrenia

OBJECTIVES

Cognitive impairment is known to occur in schizophrenia, and may be marked in institutionalised patients. The aim of this study was to determine whether it ever warrants an additional diagnosis of dementia.

METHODS

A population of chronic schizophrenic patients who were aged 65 or younger and showed no organic risk factors for dementia were screened for presence of disorientation. Any showing this underwent neuropsychological testing, physical investigations, and structural and functional neuroimaging. Information about day to day cognitive function was also obtained from carers.

RESULTS

Eight patients aged 28 to 64 were identified who showed disorientation; in all cases this was accompanied by general intellectual impairment and objective evidence of a dementia syndrome. The patients' schizophrenic symptoms were unexceptional and did not seem sufficient to account for their cognitive impairment. Neuropsychological testing disclosed relative sparing of visual and visuospatial function and language syntax, but pervasive deficits in memory and executive function. Brain CT demonstrated only minor abnormalities but most of the patients showed frontal or temporal hypoperfusion on SPECT.

CONCLUSIONS

Dementia in schizophrenia seems to be a real entity with a neuropsychological signature similar to that of frontotemporal dementia. Functional but not structural imaging abnormalities may also be characteristic.

Insight changes in acute psychotic episodes: a prospective study of Hong Kong Chinese patients

Insight impairment occurs commonly in psychotic disorders (including mood episodes with psychotic symptoms). The aim of the present study is to measure changes of insight over the course of a psychotic episode and to investigate its relationships with symptoms and neurocognitive functions, as well as psychosocial factors. Insight was assessed at weekly intervals in 80 consecutive inpatients presenting with a psychotic episode by using a Chinese translation of the Scale to Assess Unawareness of Mental Disorder (SUMD). The relationships between insight change and other variables were explored. Modest but significant changes in insight were found in both directions with clinical resolution of psychotic symptoms. In particular, insight "declined" as symptoms improved in a number of patients. In addition, changes in insight score correlated with changes in Wisconsin Card Sorting Test (WCST) performance. More changes in insight (in either direction) tended to occur in younger patients. These results indicated that adequate control of psychotic symptoms and improvement in neuropsychological functioning might be associated with better insight recovery.

Improvement in cognition associated with novel antipsychotic drugs: a direct drug effect or reduction of EPS?

BACKGROUND

Administration of novel, versus classic, antipsychotic agents to patients suffering from psychosis is associated both with moderately better scores on cognitive tests, and with fewer extrapyramidal symptoms (EPS). Because improved motor functioning may enable better performance on some components of cognitive test batteries, and because the advantages of the novel antipsychotics on cognitive performance are not very large, it is sometimes difficult to discern if improvement in a given cognitive task is due to a direct effect of the novel antipsychotic drug, or is secondary to the novel drug's decreased propensity to induce EPS. In an attempt to distinguish between these two possibilities, the present study examined the ability of patients suffering from schizophrenia receiving classic, versus novel antipsychotics, to perform a computerized visuo-motor test (VMT). VMT assesses planning capabilities, attention and executive functions known to be impaired in schizophrenia, which are suggested to be affected by novel antipsychotics.

METHODS

Seventy-six patients suffering from schizophrenia or schizophreniform disorder, receiving haloperidol (23 patients, mean dose 10.01+/-6.1mg/day), olanzapine (26 patients, mean dose 10.56 +/- 4.9 mg/day) or risperidone (27 patients, mean dose 4.35 +/- 1.7 mg/day) were assessed for EPS using the parkinsonian subscale of the Extrapyramidal Symptom Rating Subscale (ESRS), and with the VMT.

RESULTS

Cognitive functioning as measured by the VMT was better for patients receiving risperidone or olanzapine, compared with those receiving haloperidol (F=6.636, df=2,67, P=0. 002), while the patients receiving haloperidol or risperidone suffered from more severe EPS compared with the patients receiving olanzapine (F=3.996, df=2,71, P=0.023).

DISCUSSION

Although the patients receiving risperidone suffered from EPS similar in severity to the EPS of the patients receiving haloperidol, their performance on a task involving visuo-motor and attentional skills was similar to that of the patients receiving olanzapine. This finding implies that there is a dissociation between the antipsychotic drug's ability to affect cognitive functioning, and EPS. This dissociation indirectly suggests that the advantages offered by novel antipsychotics on cognitive performance are a direct effect, rather than being entirely mediated by improved movement abilities.

Semantic verbal fluency deficit as a familial trait marker in schizophrenia

This study examined neurocognitive deficits as familial vulnerability factors to schizophrenia. Twenty-three Chinese schizophrenic patients, 21 of their non-psychotic siblings and 26 healthy volunteers, matched for age, sex and education, were assessed by using a battery of neurocognitive tests including: Wisconsin Card Sorting Test (WCST), semantic verbal fluency, logical memory, digit span, information, comprehension and similarity. The results showed that siblings had significantly less word output in the verbal fluency test as compared to controls. No significant difference was found between siblings and controls for other tests except that a trend difference was noted for the performance on the similarity test and number of categories completed on the WCST. The verbal fluency abnormality can be considered as a familial trait marker for schizophrenia. Relationships between the residual symptoms after an acute psychotic episode and the magnitude of familial risk were examined. More severe residual symptoms of probands at clinical remission could be predicted by their older age of onset and by better verbal fluency performance in their non-psychotic siblings. This tentatively suggests that patients with a milder genetic form of schizophrenic illness may have a more severe environmental contribution to cerebral insult according to the multifactorial/threshold model. The environmental cerebral insult may cause structural abnormalities leading to incomplete remission of clinical symptoms.