Review of cognition and brain structure in schizophrenia: profiles, longitudinal course, and effects of treatment

Neuropathways of theory of mind in schizophrenia: A systematic review and meta-analysis

BACKGROUND

Social cognition is significantly associated with daily functioning in patients with schizophrenia. Its neural basis remains unknown.

METHODS

A systematic literature search was performed. Studies using imaging to measure theory of mind (ToM) in schizophrenia were identified. Imaging data were synthesized using the seed-based d mapping approach. Potential neuropathways were hypothesized based on the identified brain regions activated during ToM tasks.

RESULTS

A total of 25 studies were included in the present study. Compared with healthy people, patients with schizophrenia showed hyperactivations in superior longitudinal fasciculus II and hypoactivations in superior frontal gyrus, precuneus and cuneus, and precentral gyrus during ToM tasks. The primary brain regions involved in the potential neuropathways in schizophrenia were the middle temporal gyrus, superior and inferior frontal gyrus, and supplementary motor areas.

CONCLUSION

Deactivated brain regions in schizophrenia overlapped with the default mode and salience networks. Our findings shed light on how to develop a diagnostic tool for deficits in social cognition using neuroimaging techniques and effective therapeutic interventions to rectify dysfunction in schizophrenia.

Physical activity and childhood trauma experiences in patients with schizophrenia or bipolar disorders

BACKGROUND

Physical activity promotes resilience and reduces stress. Here we aimed to clarify the impact of physical activity and childhood trauma experiences on current mood and cognitive function in patients with schizophrenia (SZ) or bipolar disorders (BD).

METHODS

Three-hundred-and-six patients with DSM-IV schizophrenia (SZ) or bipolar disorder (BD) were included in the study. Diagnoses were assessed using the Structured Clinical Interview for DSM-IV Axis I disorders (SCID-I). Physical activity was measured as hours spent on any regular physical activity per week. All patients underwent a neuropsychological test battery. History of Childhood trauma was assessed using the Childhood Trauma Questionnaire and mood symptoms were assessed with the Inventory of Depressive Symptoms.

RESULTS

Patients with childhood trauma who were physically inactive (˂90 min per week) had the most severe clinical profile, characterised by the highest depressive symptoms (p ˂ 0.001) and lowest performance on working memory tasks (p ˂ 0.001). Among patients with childhood trauma, those who were physically active (≥90 min per week) had better working memory performance than physically inactive patients (p = 0.02).

DISCUSSION

A history of childhood trauma was associated with poorer working memory and more depressive symptoms only in patients who were physically inactive, suggesting a possible protective factor of physical activity in severe mental disorder.

A Feasibility Study on the Use of the Method of Loci for Improving Episodic Memory Performance in Schizophrenia and Non-clinical Subjects

We investigated the feasibility of a short intervention using the Method of Loci (MoL), a well-known visuospatial mnemonic, to improve episodic memory recall performance in schizophrenia. The MoL training protocol comprised encoding and recall of two lists of items (words and images), a training session and practice with MoL. Then, participants had the opportunity to put into practice the newly learned MoL and were instructed to encode and recall two new lists of items using. This approach was first validated with healthy individuals (N = 71). Subsequently, five individuals with schizophrenia completed the protocol. Improvement in healthy individuals was observed for the word list (Wilcoxon effect size r = 0.15). No significant memory improvement was denoted in the schizophrenia group, possibly due to participants' difficulties using the method efficiently and due to fatigue. The MoL seems to require episodic memory, working memory monitoring and executive functions, making it suboptimal for a population with impairments in all those domains. Future research should examine the use of other strategies, better suited for individuals with cognitive impairments like those found in schizophrenia.

Contributions of childhood trauma and atypical development to increased clinical symptoms and poor functioning in recent onset psychosis

AIM

The trauma-psychosis cycle proposes an interactive relationship between impaired developmental and cognitive trajectory, childhood trauma exposure, and increased risk for psychosis. This study explored how childhood trauma (CT) and atypical development (AD) impact clinical course in an early psychosis cohort.

METHODS

A retrospective chart review of behavioural and clinical research data was conducted with individuals ages 12 to 40 (N = 508; 72.4% males) evaluated by an early psychosis program.

RESULTS

CT exposure was associated with earlier onset of full threshold psychosis, more hospitalizations, higher ratings of negative symptoms, and increased likelihood of engaging in suicidal behaviour. AD alone was associated with earlier onset of psychosis symptoms, higher ratings of negative symptoms and greater likelihood of engaging in non-suicidal self-injury. The combination of CT and AD was associated with the earliest symptom onset and poorest psychosocial functioning.

CONCLUSIONS

The findings contribute to our understanding of heterogeneity in the early psychosis population and highlight the specific risk factors that could be targets in treatment.

Decreased medial entorhinal cortical thickness in olanzapine exposed female rats is not ameliorated by exercise

Aerobic exercise has been associated with hippocampal plasticity, both in healthy adults and in psychosis patients, but its impact on cortical regions remains unclear. The entorhinal cortex serves as a critical gateway for the hippocampus, and recent studies suggest that this region may also be impacted following an exercise regime. In order to investigate the effects of antipsychotic medications and exercise on the entorhinal cortex, female rats were chronically administered either olanzapine or vehicle and were either sedentary or had access to a running wheel for 9 weeks. Olanzapine-treated rats had decreased medial entorhinal cortical thickness compared to vehicle-treated rats. A statistically significant interaction was observed for layer II of the entorhinal cortex, with exercising rats having significantly greater thickness compared to sedentary rats in the vehicle group, but not the olanzapine group. Greater total entorhinal and lateral entorhinal cortical thickness was associated with greater average activity. In exercising rats, decreasing glucose intolerance was associated with larger total entorhinal and layer II cortical thickness. Lower fasting insulin levels were associated with greater total entorhinal, lateral entorhinal, and layer II cortical thickness. The relationship between increased activity and greater entorhinal cortical thickness was mediated by reduced fasting insulin, indicating that regulation of metabolic risk factors may contribute to impact of aerobic exercise on the entorhinal cortex. Aerobic exercise may be helpful in counteracting metabolic side effects of antipsychotic medications and managing these side effects may be key to promoting entorhinal cortical plasticity in patients treated with second-generation antipsychotic drugs.

The relationship between physical activity, clinical and cognitive characteristics and BDNF mRNA levels in patients with severe mental disorders

Background: Here we aimed to clarify the association of physical activity with cognitive function and current mood in severe mental disorders in the most extensive sample to date. Secondly, we aimed to investigate the relationship between physical activity and BDNF mRNA levels.Methods: Three hundred and six patients with a DSM-IV schizophrenia (SZ) or bipolar disorder (BD) spectrum diagnosis were included. Clinical characteristics were assessed using the Structured Clinical Interview for DSM-IV. Depressive symptomatology was measured using the Inventory of Depressive Symptoms (IDS-C) and the Calgary Depression Scale for Schizophrenia (CDSS). All patients underwent neuropsychological assessment. Physical activity was measured as hours spent on any regular physical activity (≥ or ˂90 min) per week. BDNF mRNA was measured in plasma using standardised procedures.Results: Patients with ≥90 min of physical activity per week had fewer depressive symptoms (P ˂0.001, Cohen's d = 0.48) and performed significantly better on working memory (P ˂ 0.001, d = 0.44) and executive functioning tasks (P ˂ 0.001, d = 0.50) compared to the ˂90-min group. BDNF mRNA was positively associated with physical activity (P = 0.046) and cognitive functioning (P = 0.037).Conclusions: Our study suggests a positive association between self-reported physical activity, cognitive function, mood and BDNF mRNA levels in severe mental disorders.

Neural correlates of global and specific cognitive deficits in schizophrenia

Cognitive deficits are a core feature of schizophrenia, but the neural mechanisms that contribute to these characteristics are not fully understood. This study investigated whether volume of the dorsal lateral prefrontal cortex (DLPFC), inferior frontal gyrus (IFG), hippocampus, and white matter were associated with impairment in specific cognitive domains, including executive functioning, working memory, verbal memory, verbal fluency, processing speed, versus global functioning. The multi-site data used in this study was collected from the Bipolar and Schizophrenia Network on Intermediate Phenotypes (B-SNIP), and consisted of 206 healthy controls and 247 individuals with either schizophrenia or schizoaffective disorder. The neuroimaging data was segmented based on the Destrieux atlas in FreeSurfer. Linear regression analyses revealed that global cognition, executive functioning, working memory, and processing speed were associated with all brain structures, except the DLPFC was only associated with executive fucntion. When controlling for the global cognitive deficit, executive function was trending significance with white matter, but continued to be associated with the DLPFC and IFG, as did the association between processing speed and the hippocampus. These findings suggest that volumes of the DLPFC, IFG, hippocampus, and white matter are associated with the global cognitive impairment seen in schizophrenia, but some brain structures may also be specifically related to domain-specific deficits (primarily executive function) over-and-beyond the global cognitive deficit.

Targeting recovery in first episode psychosis: The importance of neurocognition and premorbid adjustment in a 3-year longitudinal study

INTRODUCTION

Recovery in psychotic disorders remains a major challenge across mental health. Identifying predictors of recovery in first psychotic episodes is a priority in order to increase knowledge on underlying mechanisms of the illness and to obtain objective severity markers at initial phases. In this study we gathered sociodemographic, clinical and cognitive data to explore predictive variables of recovery after three years follow-up in a sample of 399 patients with a first episode of psychosis (FEP).

MATERIAL AND METHOD

This is a longitudinal study including patients with a FEP. A dichotomic variable of recovery was created according to symptomatic and functional outcome after 3years follow-up. Significant variables in univariate analysis were entered into a binary logistic regression to obtain a multivariate prediction model of recovery.

RESULTS

The predictive model was statistically significant and classified an overall of 76% of patients correctly, specifically 86.7% of patients that would not recover and 55% of the patients that would recover. From all the variables that where significantly different between recovered and not recovered patients, only speed of processing, executive functions and premorbid adjustment were found to be significant predictors of recovery.

DISCUSSION

This study provides evidence that the degree of basal impairment in cognitive functions related to the Prefrontal Cortex and a worst premorbid adaptation predict in a significant way which patients are less likely to recover three years after a FEP.

The developmental origins of metacognitive deficits in schizophrenia

The deficits in metacognition have been observed in schizophrenia but developmental roots of impaired metacognition are not well understood. Accordingly, this study compared metacognitive abilities of patients with schizophrenia and healthy group and examined the relationship between childhood trauma, attachment style and caregiver attitudes with metacognitive capacity which might contribute to metacognitive deficits in patient group. 35 patients with schizophrenia and 35 healthy people were included in the study. Metacognitive capacity was measured using the Metacognition Assessment Scale Abbreviated (MAS-A). This scale comprises four domains: self-reflectivity, understanding other's mind, decentration and mastery. Group comparisons revealed that schizophrenia patients had greater deficits in metacognitive ability. We found that the report of childhood emotional abuse, a pattern of anxious attachment and over protection by caregivers were uniquely related to metacognitive capacity.

Influence of interactions between genes and childhood trauma on refractoriness in psychiatric disorders

Psychiatric disorders are excellent disease models in which gene-environmental interaction play a significant role in the pathogenesis. Childhood trauma has been known as a significant environmental factor in the progress of, and prognosis for psychiatric illness. Patients with refractory illness usually have more severe symptoms, greater disability, lower quality of life and are at greater risk of suicide than other psychiatric patients. Our literature review uncovered some important clinical factors which modulate response to treatment in psychiatric patients who have experienced childhood trauma. Childhood trauma seems to be a critical determinant of treatment refractoriness in psychotic disorder, bipolar disorder, major depressive disorder, and post-traumatic stress disorder. In patients with psychotic disorders, the relationship between childhood trauma and treatment-refractoriness appears to be mediated by cognitive impairment. In the case of bipolar disorder, the relationship appears to be mediated by greater affective disturbance and earlier onset, while in major depressive disorder the mediating factors are persistent, severe symptoms and frequent recurrence. In suicidal individuals, childhood maltreatment was associated with violent suicidal attempts. In the case of PTSD patients, it appears that childhood trauma makes the brain more vulnerable to subsequent trauma, thus resulting in more severe, refractory symptoms. Given that several studies have suggested that there are distinct subtypes of genetic vulnerability to childhood trauma, it is important to understand how gene-environment interactions influence the course of psychiatric illnesses in order to improve therapeutic strategies.

Conceptualization and treatment of negative symptoms in schizophrenia

Negative symptoms of schizophrenia including social withdrawal, diminished affective response, lack of interest, poor social drive, and decreased sense of purpose or goal directed activity predict poor functional outcomes for patients with schizophrenia. They may develop and be maintained as a result of structural and functional brain abnormalities, particularly associated with dopamine reward pathways and by environmental and psychosocial factors such as self-defeating cognitions and the relief from overstimulation that accompanies withdrawal from social and role functioning. Negative symptoms are more difficult to treat than the positive symptoms of schizophrenia and represent an unmet therapeutic need for large numbers of patients with schizophrenia. While antipsychotic medications to treat the symptoms of schizophrenia have been around for decades, they have done little to address the significant functional impairments in the disorder that are associated with negative symptoms. Negative symptoms and the resulting loss in productivity are responsible for much of the world-wide personal and economic burden of schizophrenia. Pharmacologic treatments may be somewhat successful in treating secondary causes of negative symptoms, such as antipsychotic side effects and depression. However, in the United States there are no currently approved treatments for severe and persistent negative symptoms (PNS) that are not responsive to treatments for secondary causes. Pharmacotherapy and psychosocial treatments are currently being developed and tested with severe and PNS as their primary targets. Academia, clinicians, the pharmaceutical industry, research funders, payers and regulators will need to work together to pursue novel treatments to address this major public health issue.

A frame of mind from psychiatry

A distinctive characteristic of psychiatry is that it is a discipline that deals with both the physical and the mental lives of individuals. Largely because of this characteristic, different models are used for different disorders, however, there is still a remnant tendency towards reductionist views in the field. In this paper I argue that the available empirical evidence from psychiatry gives us reasons to question biological reductionism and that, in its place, we should adopt a pluralistic explanatory model that is more suited to the needs of the discipline and to the needs of the patients it is meant to help. This will allow us to retain psychiatry as an autonomous science that can productively co-exist with neuroscience while also giving patients the kind of attention they need. I further argue that this same evidence supports a view of the mind that is anti-reductive and that allows that causation can be both bottom-up and top-down and that such a view is available in emergentism coupled with an interventionist model of causation.

A Role for Estrogen in Schizophrenia: Clinical and Preclinical Findings

Gender differences in schizophrenia have been extensively researched and it is being increasingly accepted that gonadal steroids are strongly attributed to this phenomenon. Of the various hormones implicated, the estrogen hypothesis has been the most widely researched one and it postulates that estrogen exerts a protective effect by buffering females against the development and severity of the illness. In this review, we comprehensively analyse studies that have investigated the effects of estrogen, in particular 17β-estradiol, in clinical, animal, and molecular research with relevance to schizophrenia. Specifically, we discuss the current evidence on estrogen dysfunction in schizophrenia patients and review the clinical findings on the use of estradiol as an adjunctive treatment in schizophrenia patients. Preclinical research that has used animal models and molecular probes to investigate estradiol's underlying protective mechanisms is also substantially discussed, with particular focus on estradiol's impact on the major neurotransmitter systems implicated in schizophrenia, namely, the dopamine, serotonin, and glutamate systems.

Premorbid adjustment and clinical correlates of cognitive impairment in first-episode psychosis. The PEPsCog Study

BACKGROUND

The extent to which socio-demographic, clinical, and premorbid adjustment variables contribute to cognitive deficits in first-episode schizophrenia spectrum disorders remains to be ascertained.

AIMS

To examine the pattern and magnitude of cognitive impairment in first-episode psychosis patients, the profile of impairment across psychosis subtypes and the associations with premorbid adjustment.

METHODS

226 first-episode psychosis patients and 225 healthy controls were assessed in the PEPsCog study, as part of the PEPs study.

RESULTS

Patients showed slight to moderate cognitive impairment, verbal memory being the domain most impaired compared to controls. Broad affective spectrum patients had better premorbid IQ and outperformed the schizophrenia and other psychosis groups in executive function, and had better global cognitive function than the schizophrenia group. Adolescent premorbid adjustment together with age, gender, parental socio-economic status, and mean daily antipsychotic doses were the factors that best explained patients' cognitive performance. General and adolescent premorbid adjustment, age and parental socio-economic status were the best predictors of cognitive performance in controls.

CONCLUSIONS

Poorer premorbid adjustment together with socio-demographic factors and higher daily antipsychotic doses were related to a generalized cognitive impairment and to a lower premorbid intellectual reserve, suggesting that neurodevelopmental impairment was present before illness onset.

A systematic review of cognitive function in first-episode psychosis, including a discussion on childhood trauma, stress, and inflammation

OBJECTIVE

To carry out a systematic review of the literature addressing cognitive functions in first-episode psychosis (FEP), divided into domains. Although this is not a full "cognitive-genetics-in-schizophrenia review," we will also include putative ideas of mechanism(s) behind these impairments, focusing on how early stress, and genetic vulnerability may moderate cognitive function in psychosis.

METHOD

Relevant studies were identified via computer literature searches for research published up to and including January 2013, only case-control studies were included for the neurocognitive meta-analysis.

RESULTS

Patients with FEP present global cognitive impairment compared to healthy controls. The largest effect size was observed for verbal memory (Cohen's d effect size = 2.10), followed by executive function (effect size = 1.86), and general IQ (effect size = 1.71). However, effect sizes varied between studies.

CONCLUSION

Cognitive impairment across domains, up to severe level based on Cohen's effect size, is present already in FEP studies. However, differences in levels of impairment are observed between studies, as well as within domains, indicating that further consolidation of cognitive impairment over the course of illness may be present. Cognitive abnormalities may be linked to a neurodevelopmental model including increased sensitivity to the negative effect of stress, as well as genetic vulnerability. More research on this field is needed.

BDNF val66met modulates the association between childhood trauma, cognitive and brain abnormalities in psychoses

OBJECTIVE

Brain derived neurotrophic factor (BDNF) is important for brain development and plasticity, and here we tested if the functional BDNF val66met variant modulates the association between high levels of childhood abuse, cognitive function, and brain abnormalities in psychoses.

METHOD

249 patients with a broad DSM-IV schizophrenia spectrum disorder or bipolar disorder were consecutively recruited to the TOP research study (mean±age: 30.7±10.9; gender: 49% males). History of childhood trauma was obtained using the Childhood Trauma Questionnaire. Cognitive function was assessed through a standardized neuropsychological test battery. BDNF val66met was genotyped using standardized procedures. A sub-sample of n=106 Caucasians with a broad DSM-IV schizophrenia spectrum disorder or bipolar disorder (mean±age: 32.67±10.85; 49% males) had data on sMRI.

RESULTS

Carriers of the Methionine (met) allele exposed to high level of childhood abuse demonstrated significantly poorer cognitive functioning compared to homozygotic Valine (val/val) carriers. Taking in consideration multiple testing, using a more conservative p value, this was still shown for physical abuse and emotional abuse, as well as a trend level for sexual abuse. Further, met carriers exposed to high level of childhood sexual abuse showed reduced right hippocampal volume (r(2)=0.43; p=0.008), and larger right and left lateral ventricles (r(2)=0.37; p=0.002, and r(2)=0.27; p=0.009, respectively). Our findings were independent of age, gender, diagnosis and intracranial volume.

CONCLUSION

Our data demonstrate that in patients with psychoses, met carriers of the BDNF val66met with high level of childhood abuse have more cognitive and brain abnormalities than all other groups.

Cognitive profiles of three clusters of patients with a first-episode psychosis

OBJECTIVE

The primary objective was to identify specific groups of patients with a first-episode psychosis based on family history, obstetric complications, neurological soft signs, and premorbid functioning. The secondary objective was to relate these groups with cognitive variables.

METHOD

A total of 62 first-episode psychoses were recruited from adult and child and adolescent mental health services. The inclusion criteria were patients between 7 and 65 years old (real range of the samples was 13-35 years old), two or more psychotic symptoms and less than one year from the onset of the symptoms. Premorbid functioning (PAS), soft signs (NES), obstetric complications and a neuropsychological battery (CPT, TMTA/TMTB, TAVEC/TAVECI, Stroop, specific subtest of WAIS-III/WISC-IV) were administered.

RESULTS

We found three clusters: 1) higher neurodevelopment contribution (N=14), 2) higher genetic contribution (N=30), and 3) lower neurodevelopment contribution (N=18). Statistical differences were found between groups in TMTB, learning curve of the TAVEC, digits of the WAIS and premorbid estimated IQ, the cluster 1 being the most impaired.

CONCLUSIONS

A cluster approach could differentiate several groups of patients with different cognitive performance. Neuropsychological interventions, as cognitive remediation, should be addressed specifically to patients with more impaired results.

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.

Special biological issues in the management of women with schizophrenia

Schizophrenia is a debilitating and pervasive mental illness with devastating effects on psychological, cognitive and social wellbeing, and for which current treatment options are far from ideal. Gender differences and the influence of the female reproductive life cycle on the onset, course and symptoms of schizophrenia and the discovery of estrogen's remarkable psychoprotective properties in animal models led to the proposal of the 'estrogen protection hypothesis' of schizophrenia. This has fueled the recent successful investigation of estradiol as a potential adjuvant therapeutic agent in the management of schizophrenia in women. This review explains the scientific rationale behind the estrogen hypothesis and how it can be clinically utilized to address concerns unique to the care of women with schizophrenia.

Heritability of multivariate gray matter measures in schizophrenia

Structural brain measures are employed as endophenotypes in the search for schizophrenia susceptibility genes. We analyzed two independent structural imaging datasets with voxel-based morphometry and with source-based morphometry, a multivariate, independent components analysis, to determine the stability and heritability of regional gray matter concentration abnormalities in schizophrenia. The samples comprised 209 and 102 patients with schizophrenia and 208 and 96 healthy volunteers, respectively. The second sample additionally included non-ill siblings of participants with and without schizophrenia. A standard voxel-based analysis showed reproducible regional gray matter deficits in the affected participants compared with unrelated, unaffected controls in both datasets: patients showed significant gray matter concentration deficits in cortical frontal, temporal, and insular lobes. Source-based morphometry (SBM) was applied to the gray matter images of the entire sample to determine the effects of diagnosis on networks of covarying structures. The SBM analysis extracted 24 significant sets of covarying regions (components). Four of these components showed significantly lower gray matter concentrations in patients (p < .05). We determined the familiality of the observed SBM components based on 66 sibling pairs (25 discordant for schizophrenia). Two components, one including the medial frontal, insular, inferior frontal, and temporal lobes, and the other including the posterior occipital lobe, showed significant familiality (p < .05). We conclude that structural brain deficits in schizophrenia are replicable, and that SBM can extract unique familial and likely heritable components. SBM provides a useful data reduction technique that can provide measures that may serve as endophenotypes for schizophrenia.

Is cognitive impairment following early life stress in severe mental disorders based on specific or general cognitive functioning?

Schizophrenia spectrum and bipolar disorder are characterized by high levels of childhood trauma as well as of cognitive dysfunction. Our aim is to investigate the association between these two factors in the largest study in the literature so far. A total of 406 patients with schizophrenia spectrum- or bipolar disorders were recruited from a catchment area based organization in Oslo, Norway. Information about early life stress was obtained using the Childhood Trauma Questionnaire (CTQ). Cognitive function was assessed through a comprehensive and standardized neuropsychological test battery. Physical abuse, sexual abuse and physical neglect were significantly associated with reduced scores on working memory and executive function scales (p=0.04 to p<0.001), and verbal and performance tasks from the Wechsler Abbreviated Scale of Intelligence (WASI) (p=0.059 to p<0.001). When verbal and performance tasks from the WASI were added into a multivariate regression model, the association between CTQ and the specific cognitive domains decreased, and only WASI scores remained statistically significant. Our results indicate that childhood trauma is associated with a reduction in cognitive function across cognitive domains in patients with schizophrenia spectrum- and bipolar disorders, in particular working memory and executive function as well as general cognition. Moreover, these dysfunctions seem to be driven by underlying deficits in general cognitive tasks as measured by the WASI.

Treating patients with schizophrenia deficit with erythropoietin?

This systematic review summarizes and critically appraises the literature on the effect of erythropoietin (EPO) in schizophrenia patients and the pathophysiological mechanisms that may explain the potential of its use in this disease. EPO is mainly known for its regulatory activity in the synthesis of erythrocytes and is frequently used in treatment of chronic anemia. This cytokine, however, has many other properties, some of which may improve the symptoms of psychiatric illness. The review follows the preferred reporting items for systematic reviews and meta-analysis (PRISMA) statement guidelines. Three databases (Medline, Web of Science, and Cochrane) were searched combining the search terms 'erythropoietin AND (psychotic disorders OR schizophrenia)'. Seventy-eight studies were included in qualitative synthesis, a meta-analytic approach being prohibited. The findings suggest that several EPO cerebral potential properties may be relevant for schizophrenia treatment, such as neurotransmission regulation, neuroprotection, modulation of inflammation, effects on blood-brain barrier permeability, effects on oxidative stress and neurogenesis. Several potentially detrimental side-effects of EPO therapy, such as increased risk of thrombosis, cancer, increased metabolic rate and mean arterial blood pressure leading to cerebral ischemia could severely limit or halt the use of EPO. Overall, because the available data are inconclusive, further efforts in this field are warranted.

Role of estrogen treatment in the management of schizophrenia

Increasing evidence from epidemiological, preclinical and clinical studies suggests that estrogens may exert psychoprotective effects in schizophrenia. Observations of gender differences in the onset and course of schizophrenia have prompted exploration of the effects of estrogen on the CNS. The aim of this paper is to provide an overview of different applications of adjunctive estrogen as a possible treatment for symptoms of schizophrenia in both men and women. Recent trials have suggested that estrogen augmentation therapy may be able to enhance the management of schizophrenia; however, the clinical application of estrogen as a treatment has been limited by potential side effects, the most worrying being breast and uterine cancer in women, and feminization in men. Selective estrogen receptor modulators (SERMs), however, may offer therapeutic benefits for both men and women with schizophrenia without posing threat to breast and uterine tissue and without feminizing effects. The use of estrogen opens up new possibilities for both men and women in the treatment of severe mental illnesses such as schizophrenia. With further preclinical and clinical research, it is hoped that this promising field of hormone modulation can continue to evolve and eventually be translated into real therapeutic potential.

Mapping hypofrontality during letter fluency task in schizophrenia: a multi-channel near-infrared spectroscopy study

Cognitive impairment and associated frontal lobe dysfunction characterize schizophrenia. The letter fluency test (LFT) has been used as one of the most sensitive measures of the cognitive dysfunction, but the nature and topography of the hypofrontality have yet to be fully elucidated. In this study we used multi-channel near-infrared spectroscopy (NIRS), a recently developed noninvasive functional imaging technique, to measure changes in the concentration of oxygenated hemoglobin in the prefrontal cortices of 31 schizophrenia patients and 26 age- and sex-matched healthy controls during performance of the LFT. The results demonstrated reduced prefrontal cortex activation during the LFT among the schizophrenia patients in comparison with the healthy controls, even after controlling for medication. The hypofrontality was most salient in the prefrontal ventrolateral subregion bilaterally. The reduced activity appeared to be due not only to the lesser magnitude but also to the lesser fluctuation of the changes in oxygenated hemoglobin concentration. The hypofrontality appeared to be independent of the patients' symptomatological manifestations. We concluded that measuring NIRS during performance of the LFT can detect prefrontal lobe dysfunction of schizophrenia patients and may provide a new tool to monitor their treatment and course.

Hormones and schizophrenia

PURPOSE OF REVIEW

It is a well established fact that many serious mental illnesses, in particular psychoses such as schizophrenia, may have a significant hormonal aetiological component. This study aims to discuss the oestrogen protection hypothesis of schizophrenia in particular, with an emphasis on findings from the recent literature in support of this theory.

RECENT FINDINGS

Epidemiological and life-cycle data point to significant differences in the incidence and course of schizophrenia between men and women, suggesting a protective role of oestrogen. In-vitro and in-vivo preclinical research has confirmed oestradiol's interactions with central neurotransmitter systems implicated in the pathogenesis of schizophrenia, whereas results from randomized controlled trials investigating the antipsychotic potential of oestrogen have been promising. Research into other neuroactive hormones with possible effects on mental state is a field still in its infancy but is evolving rapidly.

SUMMARY

Schizophrenia and related psychoses are pervasive and debilitating conditions, for which currently available treatments are often only partially effective and entail a high risk of serious side effects. Thus, new therapeutic strategies are needed, and the literature reviewed here suggests that hormones such as oestrogen could be a viable option. It is hoped that, with further research and larger trials, the oestrogen hypothesis can be translated into effective clinical practice.

Serotonin transporter gene polymorphism, childhood trauma, and cognition in patients with psychotic disorders

OBJECTIVE

The functional polymorphism in the promoter region of the SLC6A4/5-HTT serotonin transporter gene (5-HTTLPR) has been linked to altered stress response. Carriers of the short (s-) allele have increased negative psychological reactions and stress hormone release compared with carriers of the long (l-) allele, interacting with severe life events including childhood trauma. High stress levels are associated with cognitive impairments in a variety of clinical and experimental studies. Patients with psychotic disorders are characterized both by more childhood traumatic events and abnormal stress responses and by significant but highly variable cognitive dysfunction. We hypothesize that 5-HTTLPR variations and long-term effects of childhood trauma interact and contribute to some of the variation in cognitive dysfunction seen in patients with psychotic disorders.

METHODS

Patients with psychotic disorders (schizophrenia and affective spectrums) were recruited from a catchment area-based treatment organization. History of childhood abuse was obtained by the Childhood Trauma Questionnaire. Cognitive function was assessed through a comprehensive, standardized neuropsychological test battery. 5-HTTLPR genotypes were analyzed using standard polymerase chain reaction.

RESULTS

We observed a significant interaction between 5-HTTLPR variants and childhood trauma across cognitive domains; here, homozygotic s-carriers exposed to high levels of childhood trauma (physical neglect and abuse) had significantly poorer cognitive functioning than all other groups.

CONCLUSIONS

Our results need replication but underline the importance of investigating childhood trauma and its interaction with genetic markers when studying cognitive dysfunction in patients with psychotic disorders.

Evaluation of efficacy, safety, and cognitive profile of amisulpride per se and its comparison with olanzapine in newly diagnosed schizophrenic patients in an 8-week, double-blind, single-centre, prospective clinical trial

Background. Impaired cognitive functions in schizophrenia are the major deciding factors in response to treatment. Conventional antipsychotics have minimal impact on cognitive dysfunctions and are associated with adverse effects. Atypical antipsychotics have shown promise in treatment of cognitive and negative symptoms of schizophrenia. Efforts are underway to find out the best drug amongst atypical antipsychotics. Objective. To compare efficacy, safety, and cognitive profile of amisulpride and olanzapine in the treatment of acute psychotic exacerbations of schizophrenia. Method. A prospective, randomized, double-blind, single-center, 8-week clinical trial we used. Subjects and Treatments. Seventy four patients were treated for two months with either amisulpride (400-800 mg/d) or olanzapine (10-20 mg/d). Statistics. Mann Whitney U test we used for independent samples with P < 0.05 taken as significant. Results. Brief psychiatric rating scale (BPRS) was used as a primary measure of efficacy. Other measures of efficacy and safety were also evaluated. Both amisulpride and olanzapine groups showed equivalent improvement in psychotic symptoms on BPRS scale. Less than five percent of patients suffered adverse effects only to withdraw from the study. Olanzapine group showed statistically significant (P < 0.05) weight gain compared with amisulpride group. Amisulpride group showed significant improvement (P < 0.05) in various cognitive parameters as compared to olanzapine group.

Animal models of schizophrenia emphasizing construct validity

Achieving animal models of schizophrenia which are representative of clear aspects of the illness is critical to understanding pathophysiology and developing novel treatments for the complex syndrome. This chapter reviews the various approaches that have been used in the past to create animal models of schizophrenia, including pharmacological approaches, environmental risk conditions and schizophrenia risk genes. In addition, we present a new animal model which derives directly from human tissue and brain imaging data used to develop a human schizophrenia model. This chapter emphasizes the crucial need for construct validity and of modeling discrete elements of schizophrenia's illness presentation as the way to successful advances.

The role of oestrogen and other hormones in the pathophysiology and treatment of schizophrenia

The theory that many serious mental illnesses, in particular psychoses such as schizophrenia, may have a significant hormonal aetiological component is fast gaining popularity and the support of scientific evidence. Oestrogen in particular has been substantially investigated as a potential mediator of brain function in schizophrenia. Epidemiological and life-cycle data point to significant differences in the incidence and course of schizophrenia between men and women suggests a protective role of oestrogen. In vitro and in vivo preclinical research confirms oestradiol's interactions with central neurotransmitter systems implicated in the pathogenesis of schizophrenia, while results from randomised controlled trials investigating the antipsychotic potential of oestrogen have been positive. Research into other neuroactive hormones with possible effects on mental state is a rapidly evolving field that may hold new promise. Given that schizophrenia and related psychoses are pervasive and debilitating conditions for which currently available treatments are often only partially effective and entail a high risk of serious side-effects, novel therapeutic strategies are needed. The literature reviewed in this paper suggests that hormones such as oestrogen could be a viable option, and it is hoped that with further research and larger trials, the oestrogen hypothesis can be translated into effective clinical practice.

Effectiveness of different modalities of cognitive remediation on symptomatological, neuropsychological, and functional outcome domains in schizophrenia: a prospective study in a real-world setting

OBJECTIVES

The efficacy of cognitive remediation interventions in schizophrenia has been demonstrated in several experimental studies. However, the effectiveness of such treatments in the usual setting of care of schizophrenia and a direct comparison of different modalities of interventions have not been systematically analyzed. The aim of the study was to assess the effectiveness of the cognitive subprograms of Integrated Psychological Therapy (IPT-cog) and of a computer-assisted cognitive remediation (CACR) method on symptomatological, neuropsychological and functional outcome measures in schizophrenia.

METHODS

Ninety patients with schizophrenia were assigned to IPT-cog, CACR or usual rehabilitative interventions (REHAB) in a naturalistic setting of care. Clinical, neuropsychological, and functional outcome variables were assessed at baseline and after 24 weeks of treatment.

RESULTS

Both the IPT-cog and CACR groups improved more than the comparison group with respect to all outcome variables. The more responsive cognitive domains were speed of processing and working memory. The effectiveness of the 2 remediation methods on the outcome dimensions considered was comparable. However, IPT-cog, but not CACR, was more effective than REHAB on speed of processing, and the CACR group had better outcome than both the REHAB and the IPT-cog groups when the Health of the Nation Outcome Scale was considered. Few correlations between neurocognitive and functional outcome changes were found.

CONCLUSIONS

The study demonstrates the effectiveness, although nongeneralized, of IPT-cog and CACR in schizophrenia when applied within a psychiatric and psychosocial treatment regimen representative of the usual setting and modality of care, with no evident superiority of any of the methods, and indicates that the changes in functional outcome during treatment are modestly mediated by improvement in specific cognitive domains.

Childhood trauma and cognitive function in first-episode affective and non-affective psychosis

BACKGROUND

A history of childhood trauma is reportedly more prevalent in people suffering from psychosis than in the general population. Childhood trauma has also been linked to cognitive abnormalities in adulthood, and cognitive abnormalities, in turn, are one of the key clinical features of psychosis. Therefore, this study investigated whether there was a relationship between childhood trauma and cognitive function in patients with first-episode psychosis. The potential impact of diagnosis (schizophrenia or affective psychosis) and gender on this association was also examined.

METHODS

Data were available for 138 first-episode psychosis patients and 138 geographically-matched controls recruited from a catchment area based organisation. History of childhood trauma was obtained using the Childhood Experience of Care and Abuse Questionnaire. Cognitive function was assessed through a comprehensive and standardised neuropsychological test battery.

RESULTS

A history of childhood trauma was associated with worse cognitive performances, predominantly in affective psychoses, and in male patients. No association between a history of childhood trauma and cognition was found amongst female patients, or female controls.

CONCLUSIONS

The results need replication, but underline the necessity of investigating biological and psychosocial mechanisms underlying these subjects' sensitivity to the negative effect of childhood stress.

Schizophrenia: treatment targets beyond monoamine systems

We develop the proposal in this review that schizophrenia is a syndrome made up of component symptom complexes, each with distinctive clinical correlates, pathophysiology, and selective treatments. Psychosis is the necessary component of the syndrome; it has a young-adult onset and is sensitive to current antipsychotic drugs. Cognitive dysfunction often precedes psychosis onset, does not present an episodic course, and is poorly responsive to antipsychotic drugs. Treatments for cognition are being developed largely on the basis of animal pharmacology. Drugs for component symptom complexes will theoretically be coadministered to independent symptomatic end points. Animal models, some with genetic characteristics, can be more easily and directly developed to match an individual component than to match an illness definition as broad as schizophrenia.

Abnormal cortisol awakening response predicts worse cognitive function in patients with first-episode psychosis

BACKGROUND

Cognitive impairment, particularly in memory and executive function, is a core feature of psychosis. Moreover, psychosis is characterized by a more prominent history of stress exposure, and by dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. In turn, stress exposure and abnormal levels of the main HPA axis hormone cortisol are associated with cognitive impairments in a variety of clinical and experimental samples; however, this association has never been examined in first-episode psychosis (FEP).

METHOD

In this study, 30 FEP patients and 26 controls completed assessment of the HPA axis (cortisol awakening response and cortisol levels during the day), perceived stress, recent life events, history of childhood trauma, and cognitive function. The neuropsychological battery comprised general cognitive function, verbal and non-verbal memory, executive function, perception, visuospatial abilities, processing speed, and general knowledge.

RESULTS

Patients performed significantly worse on all cognitive domains compared to controls. In patients only, a more blunted cortisol awakening response (that is, more abnormal) was associated with a more severe deficit in verbal memory and processing speed. In controls only, higher levels of perceived stress and more recent life events were associated with a worse performance in executive function and perception and visuospatial abilities.

CONCLUSIONS

These data support a role for the HPA axis, as measured by cortisol awakening response, in modulating cognitive function in patients with psychosis; however, this association does not seem to be related to the increased exposure to psychosocial stressors described in these patients.

The relationship between neurocognition and social cognition with functional outcomes in schizophrenia: a meta-analysis

The current systematic review and meta-analysis provides an extended and comprehensive overview of the associations between neurocognitive and social cognitive functioning and different types of functional outcome. Literature searches were conducted in MEDLINE and PsycINFO and reference lists from identified articles to retrieve relevant studies on cross-sectional associations between neurocognition, social cognition and functional outcome in individuals with non-affective psychosis. Of 285 studies identified, 52 studies comprising 2692 subjects met all inclusion criteria. Pearson correlations between cognition and outcome, demographic data, sample sizes and potential moderator variables were extracted. Forty-eight independent meta-analyses, on associations between 12 a priori identified neurocognitive and social cognitive domains and 4 domains of functional outcome yielded a number of 25 significant mean correlations. Overall, social cognition was more strongly associated with community functioning than neurocognition, with the strongest associations being between theory of mind and functional outcomes. However, as three-quarters of variance in outcome were left unexplained, cognitive remediation approaches need to be combined with therapies targeting other factors impacting on outcome.

Subjective rating of working memory is associated with frontal lobe volume in schizophrenia

BACKGROUND

Patients with schizophrenia commonly show deficits in working memory on objective neuropsychological measures, and brain imaging studies have documented neural abnormalities during performance of working memory tasks. It remains unclear to what extent such patients are able to accurately gauge the integrity of their working memory in their daily lives.

AIMS

We evaluated the relationship between subjective rating of working memory integrity in daily life and volumes of the frontal, temporal, and parietal lobes in patients with schizophrenia.

METHODS

Participants included 29 patients with schizophrenia and 26 healthy comparison subjects. Participants completed a structural magnetic resonance imaging (MRI) scan, the Self Report form of the Behavioral Rating Inventory of Executive Function - Adult version (BRIEF-A), and Digit Span Backwards as an objective measure of working memory. Lobar volumes were obtained using an automated processing package and adjusted for total intracranial volume.

RESULTS

The patient group reported worse working memory in daily life, and performed worse on Digit Span Backwards, than the comparison group. Within the patient group, poorer working memory in daily life was associated with smaller left and right frontal lobe volumes. Shorter backwards digit span was associated with smaller left frontal and left and right temporal lobe volumes.

CONCLUSIONS

The significant relationship between frontal lobe volumes and subjective working memory in daily life provides some support for the validity of self report measures of cognitive functioning in patients with schizophrenia, and provides further evidence for a contribution of frontal lobe abnormality to executive dysfunction in the illness.

Psychopathologic, neuropsychological and functional outcome measures during cognitive rehabilitation in schizophrenia: a prospective controlled study in a real-world setting

BACKGROUND

Cognitive dysfunction has been demonstrated in patients with schizophrenia, and this may affect patients' functional outcome. The improvement of such dysfunction by means of cognitive remediation interventions has become a relevant target in the care of schizophrenia.

OBJECTIVE

To assess the effectiveness of the cognitive subprograms of Integrated Psychological Therapy (IPT) on symptomatological, neuropsychological and functional outcome variables and to analyze the relationships between cognitive and functional outcome changes in schizophrenia.

METHODS

Thirty-two patients with schizophrenia were assigned to cognitive remediation (IPT-cog) or usual rehabilitative interventions in a naturalistic setting of care. Clinical, neuropsychological and functional outcome variables were assessed at baseline and after 24 weeks of treatment.

RESULTS

The IPT-cog group improved significantly more than the comparison group with respect to psychopathological and functional outcome variables. Moreover, only the IPT-cog group improved significantly in the neuropsychological domains of verbal and working memory, with specific significant correlations between neurocognitive performance and functional outcome changes.

CONCLUSIONS

The results of the study confirm the effectiveness of the cognitive remediation component of IPT in schizophrenia, and indicate that some of the changes in functional outcome may be mediated by improvement in specific cognitive domains.

Clarifying the diversity of first-episode psychosis: Neuropsychological correlates of clinical symptoms

BACKGROUND

Psychosis is marked by heterogeneity, which complicates effective treatment.

AIMS

Subgroups of first-episode psychosis could be found by identifying neuropsychological correlates of psychiatric symptoms.

METHODS

Ninety-two outpatients with first-episode psychosis were evaluated with the Positive and Negative Syndrome Scale (PANSS) and a comprehensive neuropsychological test battery.

RESULTS

Factor analysis of PANSS revealed five symptom dimensions. Negative symptoms were correlated with widespread neuropsychological dysfunction. Disorganization symptoms were correlated with more focused deficits in executive function, attention and processing speed implicating dysfunction in frontal-subcortical circuits. Asocial, positive and affective symptoms were not associated with cognition.

CONCLUSIONS

In first-episode psychosis, neuropsychological deficits are associated with negative and disorganization symptom dimensions, which appear to be marked by different cognitive profiles. These findings have implications for improving symptom-specific treatment.

Cognitive performance is related to cortical grey matter volumes in early stages of schizophrenia: a population-based study of first-episode psychosis

BACKGROUND

Neuropsychological deficits have been reported in association with first-episode psychosis (FEP). Reductions in grey matter (GM) volumes have been documented in FEP subjects compared to healthy controls. However, the possible inter-relationship between the findings of those two lines of research has been scarcely investigated.

OBJECTIVE

To investigate the relationship between neuropsychological deficits and GM volume abnormalities in a population-based sample of FEP patients compared to healthy controls from the same geographical area.

METHODS

FEP patients (n=88) and control subjects (n=86) were evaluated by neuropsychological assessment (Controlled Oral Word Association Test, forward and backward digit span tests) and magnetic resonance imaging using voxel-based morphometry.

RESULTS

Single-group analyses showed that prefrontal and temporo-parietal GM volumes correlated significantly (p<0.05, corrected) with cognitive performance in FEP patients. A similar pattern of direct correlations between neocortical GM volumes and cognitive impairment was seen in the schizophrenia subgroup (n=48). In the control group, cognitive performance was directly correlated with GM volume in the right dorsal anterior cingulate cortex and inversely correlated with parahippocampal gyral volumes bilaterally. Interaction analyses with "group status" as a predictor variable showed significantly greater positive correlation within the left inferior prefrontal cortex (BA46) in the FEP group relative to controls, and significantly greater negative correlation within the left parahippocampal gyrus in the control group relative to FEP patients.

CONCLUSION

Our results indicate that cognitive deficits are directly related to brain volume abnormalities in frontal and temporo-parietal cortices in FEP subjects, most specifically in inferior portions of the dorsolateral prefrontal cortex.

Schizophrenia diagnosis and anterior hippocampal volume make separate contributions to sensory gating

Impaired P50 gating is thought to reflect a core deficit in schizophrenia, but the relevant neural network is not well understood. The present study used EEG and MEG to assess sensory gating and volumetric MRI to measure hippocampal volume to investigate relationships between them in 22 normal controls and 22 patients with schizophrenia. In the schizophrenia group, anterior but not posterior hippocampal volume was smaller, and both the P50 and M50 gating ratios were larger (worse) than in controls. Independent of group, left-hemisphere M50 gating ratio correlated negatively with left anterior hippocampal volume, and right-hemisphere M50 gating ratio correlated negatively with right anterior hippocampal volume. Schizophrenia diagnosis predicted M50 gating independent of hippocampal volume. These results are consistent with the finding that hippocampus is a critical part of a fronto-temporal circuit involved in auditory gating.

Reduced frontopolar activation during verbal fluency task in schizophrenia: a multi-channel near-infrared spectroscopy study

Functional neuroimaging studies to date have shown prefrontal dysfunction during executive tasks in schizophrenia. However, relationships between hemodynamic response in prefrontal sub-regions and clinical characteristics have been unclear. The objective of this study is to evaluate prefrontal hemodynamic response related to an executive task in schizophrenia and to assess the relationship between activation in the prefrontal sub-regions and clinical status. Fifty-five subjects with schizophrenia and age- and gender-matched 70 healthy subjects were recruited for this case-control study in a medical school affiliated hospital in the Tokyo metropolitan area, Japan. We measured hemoglobin concentration changes in the prefrontal (dorsolateral, ventrolateral, and frontopolar regions) and superior temporal cortical surface area during verbal fluency test using 52-channel near-infrared spectroscopy, which enables real-time monitoring of cerebral blood volumes in the cortical surface area under a more restraint-free environment than positron emission tomography or functional magnetic resonance imaging. The two groups showed distinct spatiotemporal pattern of oxy-hemoglobin concentration change during verbal fluency test. Schizophrenia patients were associated with slower and reduced increase in prefrontal activation than healthy controls. In particular, reduced activations of the frontopolar region, rather than lateral prefrontal or superior temporal regions, showed significant positive correlations with lower global assessment of functioning scores in the patient group, although task performance was not significantly associated with the scores. These results suggest that reduced frontopolar cortical activation is associated with functional impairment in patients with schizophrenia and that near-infrared spectroscopy may be an efficient clinical tool for monitoring these characteristics.

Tone duration mismatch negativity deficits predict impairment of executive function in schizophrenia

Impairment in mismatch negativity (MMN) potentials is a robust finding in schizophrenia. There are few studies which examined the correlation between MMN deficits and neuropsychological performances. The purpose of this study was to investigate the relationship between deficits of tone duration MMN and various neuropsychological measures in schizophrenic patients (n=23). The results demonstrated a significant correlation between low MMN amplitude and poor performances of executive function in Wisconsin Card Sorting Test, Stroop Test and Trail Making Test. Our finding suggests MMN deficits in schizophrenia predict deficits of executive function and might reflect ongoing functional abnormality of fronto-temporal interaction.

Cerebral Disconnectivity: An Early Event in Schizophrenia

Neuroimaging and electrophysiological investigations have demonstrated numerous differences in brain morphology and function of chronic schizophrenia patients compared to healthy controls. Studying patients at the beginning of their disease without the confounding effects of chronicity, medication, and institutionalization may provide a better understanding of schizophrenia. Recently, at many institutions around the world, special projects have been launched for specialized treatment and research of this interesting patient group. Using the PubMed search engine in this update, the authors summarize recent investigations between January 2002 and September 2006 that focus on whether signs of disconnectivity already exist early in the disease process. They discuss gray and white matter changes, their impact on symptomatology, electroencephalogram-based studies on connectivity, and possible influences of medication. NEUROSCIENTIST 14(1):19—45, 2008. DOI: 10.1177/1073858406298391

Treatment with amisulpride and olanzapine improve neuropsychological function in schizophrenia

OBJECTIVES

Although antipsychotic drugs control acute psychotic manifestations of schizophrenia, improving cognitive symptoms is also important for long-term prognosis.

METHODS

Three hundred and seventy-seven adult patients with acute psychosis were randomised to either amisulpride (200-800 mg/d) or olanzapine (5-20 mg/d) for 6 months. Neuropsychological performance was assessed at inclusion and after 6 months in a subgroup of 26 subjects (11 treated with amisulpride and 15 with olanzapine) using the Auditory Verbal Learning Test (AVLT), the Trail Making Test (TMT) and the Controlled Oral Word Association Test (COWAT).

RESULTS

The improvement in BPRS score was similar in both treatment groups. No significant differences in test performance between groups were observed at inclusion. After 6 months, AVLT scores increased by 8.7 points in the amisulpride group and by 2.3 points in the olanzapine group (p = 0.049). Completion speed in the TMT increased by 17.4 s (amisulpride) and 15.4 s (olanzapine) for Part A and by 39.8 and 48.8 s, respectively for Part B. Performance in the COWAT improved little in both groups.

CONCLUSIONS

Both amisulpride and olanzapine produce sustained improvement in certain measures of neuropsychological performance in patients with schizophrenia; a significant improvement in score on the AVLT was observed only with amisulpride.

Neuropsychological functioning in bipolar disorder and schizophrenia

BACKGROUND

Some patients with bipolar disorder (BD) demonstrate neuropsychological deficits even when stable. However, it remains unclear whether these differ qualitatively from those seen in schizophrenia (SZ).

METHODS

We compared the nature and severity of cognitive deficits shown by 106 patients with SZ and 66 patients with BD to 316 healthy adults (NC). All participants completed a cognitive battery with 19 individual measures. After adjusting their test performance for age, sex, race, education, and estimated premorbid IQ, we derived regression-based T-scores for each measure and the six cognitive domains.

RESULTS

Both patient groups performed significantly worse than NCs on most (BD) or all (SZ) cognitive tests and domains. The resulting effect sizes ranged from .37 to 1.32 (mean=.97) across tests for SZ patients and from .23 to .87 (mean=.59) for BD patients. The Pearson correlation of these effect sizes was .71 (p<.001).

CONCLUSIONS

Patients with bipolar disorder suffer from cognitive deficits that are milder but qualitatively similar to those of patients with schizophrenia. These findings support the notion that schizophrenia and bipolar disorder show greater phenotypic similarity in terms of the nature than severity of their neuropsychological deficits.

The course of neurocognition and social functioning in individuals at ultra high risk for psychosis

OBJECTIVE

This study evaluates longitudinal neuropsychological performance and its association with clinical symptomatology and psychosocial outcome in individuals identified as ultra high risk (UHR) for psychosis.

METHODS

Thirty-five UHR individuals completed neurocognitive, clinical, and social/role functioning assessments at baseline and, on average, 8.3 months later.

RESULTS

UHR subjects showed significant cognitive deficits at baseline and 2 distinct profiles of cognitive change over time. On average, 50% demonstrated improvement in social and role functioning over the follow-up period, while the other half showed either stability or decline in functioning. Functional improvement was associated with improved processing speed and visual memory, as well as improvement in clinical symptoms over the follow-up period. In contrast, patients who did not improve functionally showed stable clinical symptoms and cognitive performance over time.

CONCLUSIONS

Although the degree of neurocognitive deficit at baseline in UHR patients does not predict psychosocial outcome, the course of neurocognitive change over the first 8 months of follow-up does differentiate patients with good and poor functional outcomes.