Insight and frontal cortical function in schizophrenia: a review

The structural neuroanatomy of metacognitive insight in schizophrenia and its psychopathological and neuropsychological correlates

Lack of insight into illness is a multidimensional phenomenon that has relevant implications on clinical course and therapy compliance. Here, we focused on metacognitive insight in schizophrenia, that is, the ability to monitor one's changes in state of mind and sensations, with the aim of investigating its neuroanatomical, psychopathological, and neuropsychological correlates. Fifty-seven consecutive patients with Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revision) diagnosis of schizophrenia were administered the Insight Scale, and comprehensive psychopathological and neuropsychological batteries. They underwent a high-resolution T1-weighted magnetic resonance imaging investigation. Gray matter (GM) and white matter (WM) volumes were analyzed on a voxel-by-voxel basis using Statistical Parametric Mapping 8. Reduced metacognitive insight was related to reduced GM volumes in the left ventrolateral prefrontal cortex, right dorsolateral prefrontal cortex and insula, and bilateral premotor area and putamen. Further, it was related to reduced WM volumes of the right superior longitudinal fasciculum, left corona radiata, left forceps minor, and bilateral cingulum. Increased metacognitive insight was related to increased depression severity and attentional control impairment, while the latter was related to increased GM volumes in brain areas linked to metacognitive insight. Results of this study suggest that prefrontal GM and WM bundles, all implied in cognitive control and self-reflection, may be the neuroanatomical correlates of metacognitive insight in schizophrenia. Further, higher metacognitive insight is hypothesized to be a risk factor for depression which may subsequently impair attention. This line of research may provide the basis for the development of cognitive interventions aimed at improving self-monitoring and compliance to treatment.

Tricks of the mind: Visual hallucinations as disorders of attention

Visual hallucinations are common across a number of disorders but to date, a unifying pathophysiology underlying these phenomena has not been described. In this manuscript, we combine insights from neuropathological, neuropsychological and neuroimaging studies to propose a testable common neural mechanism for visual hallucinations. We propose that 'simple' visual hallucinations arise from disturbances within regions responsible for the primary processing of visual information, however with no further modulation of perceptual content by attention. In contrast, 'complex' visual hallucinations reflect dysfunction within and between the Attentional Control Networks, leading to the inappropriate interpretation of ambiguous percepts. The incorrect information perceived by hallucinators is often differentially interpreted depending on the time-course and the neuroarchitecture underlying the interpretation. Disorders with 'complex' hallucinations without retained insight are proposed to be associated with a reduction in the activity within the Dorsal Attention Network. The review concludes by showing that a variety of pathological processes can ultimately manifest in any of these three categories, depending on the precise location of the impairment.

Differential relationships between set-shifting abilities and dimensions of insight in schizophrenia

BACKGROUND

To assess insight in a large sample of patients with schizophrenia and to study its relationship with set shifting as an executive function.

METHODS

The insight of a sample of 161 clinically stable, community-dwelling patients with schizophrenia was evaluated by means of the Scale to Assess Unawareness of Mental Disorder (SUMD). Set shifting was measured using the Trail-Making Test time required to complete part B minus the time required to complete part A (TMT B-A). Linear regression analyses were performed to investigate the relationships of TMT B-A with different dimensions of general insight.

RESULTS

Regression analyses revealed a significant association between TMT B-A and two of the SUMD general components: 'awareness of mental disorder' and 'awareness of the efficacy of treatment'. The 'awareness of social consequences' component was not significantly associated with set shifting.

CONCLUSIONS

Our results show a significant relation between set shifting and insight, but not in the same manner for the different components of the SUMD general score.

Self-face recognition in schizophrenia is related to insight

A core feature of schizophrenia is the breakdown of the sense of self. A widespread clinical consequence of impaired self-awareness is a lack of insight. Self-face recognition is regarded as one aspect of self-awareness; how this relates to other self-referential processes such as insight into the disorder is as yet unknown. Nineteen patients with schizophrenia performed a facial recognition task using video morphings during which an average face gradually transformed into one's own, a famous or an unfamiliar face (and vice versa). Reaction times to detect faces during the transitions were compared between patients and a matched control group. In the patient group, we also examined correlations between face recognition and insight, psychopathology, and self-evaluation. Both patients with schizophrenia and controls recognised their own faces faster than unfamiliar faces. Whereas healthy subjects recognised a famous face at an intermediate speed that did not differ significantly from the recognition of one's own and unfamiliar faces, schizophrenia patients recognised the famous face, similar to their own face, significantly faster than an unfamiliar face. Moreover, in the patient group, higher insight correlated with faster reaction times in distinguishing one's own from famous faces. Patients with schizophrenia seem to distinguish less than controls between their own and a famous face relative to an unfamiliar face. Patients with good insight into the disorder, however, were better able to differentiate between their own and a famous face. This study supports the view that self-face recognition is an indicator for higher-order self-awareness.

Co-occurring aggressive and depressive symptoms as related to overestimations of competence in children with attention-deficit/hyperactivity disorder

Research indicates that on average, children with attention-deficit/hyperactivity disorder (ADHD) overestimate their competence in various domains. ADHD also frequently co-occurs with disorders involving aggressive and depressive symptoms, which themselves seem to influence estimations of self-competence in social, academic, and behavioral domains. In particular, high levels of aggressive behavior are generally associated with overestimations of competence, and high levels of depressive symptoms are related to underestimations of competence. This paper reviews studies of overestimations of competence among children with ADHD and examines the extent to which comorbid aggressive or depressive symptoms may be influencing these estimates. Although significant challenges arise due to limited information regarding comorbidities and problematic methods used to assess overestimations of competence, existing evidence suggests that ADHD may be associated with overestimations of competence over and above co-occurring aggression. As well, studies suggest that comorbid depression may reduce the appearance of overestimations of competence in children with ADHD. Underlying mechanisms (e.g., neuropsychological deficits or self-protection) of overestimations in children with ADHD are discussed, each with particular clinical implications for the assessment and treatment of ADHD. Future research would do well to carefully consider and explicitly describe the comorbid aggressive and depressive characteristics among individuals with ADHD when overestimations of competence are examined.

Insight into illness in late-life schizophrenia: a function of illness severity and premorbid intellectual function

Impaired insight into illness is a common but poorly understood phenomenon in schizophrenia. Several studies in midlife adults with schizophrenia have reported an association between impaired insight and illness severity, executive dysfunction, premorbid intellectual function, and to a lesser degree attention. Aging is associated with a decline in attention and executive function. Thus, the relationship between cognition and insight is expected to differ between younger and older adults with schizophrenia. This study assessed this relationship among 50 patients with schizophrenia 60 years and older. Insight was explained by illness severity (16.2% of the variance) and premorbid intellectual function (23.9% of the variance), but not by attention or executive function. Our findings suggest that the predictors of insight in schizophrenia differ early and later in life. In particular, insight's association with attention and executive function observed in younger patients is attenuated by age-related changes in cognition. In contrast, premorbid intellectual function continues to be a strong predictor of insight in late life, which highlights the need to better understand and enhance cognitive function early in the course of schizophrenia.

Insight in stable schizophrenia: relations with psychopathology and cognition

OBJECTIVE

This study evaluated the relationship among insight, sociodemographic and clinical variables, symptoms and cognitive functions in a population of outpatients with stable schizophrenia, in order to identify possible contributing factors to awareness.

METHOD

Two-hundred and seventy-six consecutive outpatients with stable schizophrenia were enrolled in a cross-sectional study. All subjects were assessed by psychiatric scales and interview, and a wide neuropsychological battery. A factor analysis was performed to identify cognitive factors and multiple regression analyses were executed to test the contribution of variables considered to insight.

RESULTS

Our results showed that positive and negative symptoms, executive functions, verbal memory-learning were contributors of awareness of mental illness; positive and negative symptoms explained variability in awareness of the need for treatment; positive symptoms and executive functions contributed to awareness of the social consequences of disorder.

CONCLUSIONS

These results suggested that insight was partially influenced by positive and negative symptoms and by cognitive functions. A complex system of overlapping variables may underlie impaired insight, contributing to a different extent to specific dimensions of poor insight in patients with stable schizophrenia.

The influence of sex on cognitive insight and neurocognitive functioning in schizophrenia

Both impaired insight and cognitive deficits in schizophrenia are core features of this disorder. Previous studies have demonstrated the complex relationships between neurocognition and cognitive insight, as well as the contribution of neurocognition in explaining cognitive insight. However, there is lack of research regarding the influences of sex on the relation of neurocognition and cognitive insight. The present study sought to elucidate sex differences in cognitive insight and neurocognition in schizophrenia. Seventy three outpatients (male=39) with DSM-IV diagnosis of schizophrenia or schizoaffective disorder were enrolled in the cross-sectional study. The participants were assessed with cognitive insight using the Beck Cognitive Insight Scale, executive functions using the Wisconsin Card Sorting Test, sustained attention using the Conner's Continuous Performance Test (Second Edition), and intelligence using the Wechsler Adult Intelligence Scale-Third version, respectively. Sex differences in demographic and clinical variables were small; nevertheless, female patients had significantly later age of illness onset and higher levels of formal education than males (p<0.05). Poor cognitive insight was attributed to impairment in performance of executive function and sustained attention. Results from hierarchical regression analyses indicated sex as a moderator only in the association between cognitive insight and executive function. Our findings support an association between poor cognitive insight and neurocognitive impairment in outpatients with schizophrenia and suggest that the relationship may be sex-specific. This study highlights potential targets for effective intervention and rehabilitation in improving patients' insight toward mental illness.

No correlation between plasma NMDA-related glutamatergic amino acid levels and cognitive function in medicated patients with schizophrenia

OBJECTIVE

Disrupted glutamatergic neurotransmission and cognitive functions are key components in the pathophysiology of schizophrenia. Changes in levels of serum/plasma glutamatergic amino acids, such as glutamate, glycine, and L- and D-serine may be possible clinical markers. Following our recent findings that peripheral blood levels of endogenous glycine, alanine, and especially D-serine may reflect the degree/change in symptoms in schizophrenia, here we investigated whether these plasma amino acid levels may also reflect the status of cognitive functions in schizophrenia.

METHODS

One hundred eight Japanese patients with schizophrenia were evaluated with cognitive assessment batteries at the time that plasma glutamatergic amino acid levels were measured using high-performance liquid chromatography. For analyzing cognitive functions, batteries for reflection prefrontal cortex cognitive functions, verbal fluency tests, the Stroop test, and the digit span forward and backward tests were administered.

RESULTS

Results failed to show a relationship between any plasma glutamatergic amino acid level and cognitive batteries.

CONCLUSIONS

Our results suggest that plasma glutamatergic amino acid levels may be significant biological markers that reflect the condition or a dramatic change at the time of testing, especially in severely affected patients, but they do not reflect cognitive function.

Ventromedial-frontopolar prefrontal cortex atrophy correlates with insight loss in frontotemporal dementia and Alzheimer's disease

Loss in insight is a major feature of frontotemporal dementia (FTD) but has been investigated relatively little. More importantly, the neural basis of insight loss is still poorly understood. The current study investigated insight deficit profiles across a large cohort of neurodegenerative patients (n = 81), including FTD and Alzheimer's disease (AD) patients. We employed a novel insight questionnaire, which tapped into changes across different domains: social interaction, emotion, diagnosis/treatment, language, and motivation. FTD subtypes varied considerably for insight loss, with the behavioral variant worst and the progressive non-fluent variant least affected. All other subtypes and AD showed milder but consistent insight loss. Voxel-based morphometry analysis revealed that overall insight loss correlated with ventromedial and frontopolar prefrontal atrophy, with exception of social interaction and emotion insight loss, which additionally correlated with lateral temporal and amygdala atrophy, respectively. Our results show that patients with neurodegenerative conditions show variable loss of insight, with ventromedial and frontopolar cortex regions appearing to be particularly important for insight.

Distinct neural responses used to gain insight into hallucinatory perception in patients with schizophrenia

OBJECTIVE

Most patients with schizophrenia suffer from various types of hallucinations, which commonly produce distress, functional disability or behavioral dyscontrol. The neural process of adapting to hallucinations in patients with schizophrenia remains unknown.

METHODS

Functional magnetic resonance imaging (MRI) responses to an unusual threatening visual stimulus designed to simulate a hallucinatory experience were compared between 16 patients with schizophrenia and 17 healthy controls. Linear and quadratic repetition-variant as well as repetition-invariant responses to the stimulus were compared between the two groups.

RESULTS

Repetition-invariant responses were similar between patients with schizophrenia and healthy controls. Patients with schizophrenia exhibited a linear activation pattern in the anterior cingulate, whereas healthy controls exhibited a parabolic activation pattern in the anterior prefrontal cortex, occipito-temporal junction and amygdala.

CONCLUSIONS

These results provide us with a better understanding of the neural processes involved in gaining insight into unreality. Patients with schizophrenia may use a salience-related region instead of reality monitoring-related regions to react to the unusual stimuli, and this peculiarity of the neural processes may be related to vulnerability to psychosis.

Schizophrenia with preserved insight is associated with increased perfusion of the precuneus

BACKGROUND

Preserved insight into illness has been suggested to be predictive of outcome in patients with schizophrenia. We aimed to investigate the functional substrate underlying preserved insight in these patients.

METHODS

We recruited patients with paranoid schizophrenia and healthy controls matched for age and sex. Patients were grouped according to preserved or impaired insight into illness using the Scale to assess Unawareness of Mental Disorder (SUMD). Whole-brain technetium-99m ethyl cysteinate dimer single photon emission computed tomography regional cerebral blood flow was compared at the voxel level between the 2 groups using a statistical parametric map (voxel-level significance of p < 0.001, uncorrected; cluster level significance of p < 0.05, uncorrected).

RESULTS

We enrolled 31 right-handed patients with schizophrenia and 18 controls in our study. Twenty-one (67.7%) patients had preserved insight. The 2 groups did not differ significantly in demographic and clinical characteristics or in treatment. Compared with controls, the whole group of patients showed bilateral frontotemporal hypoperfusions, with no statistical difference between patients with preserved or impaired insight for these areas. Patients with preserved insight showed significantly increased perfusion of the bilateral precuneus relative to those with impaired insight.

LIMITATIONS

Patients with subtypes other than paranoid schizophrenia have to be investigated to assess whether involvement of the precuneus in patients with preserved insight can be identified across the full spectrum of subtypes and symptoms of schizophrenia. Moreover, our study concerned only the central dimension (awareness of mental disorder) of 1 scale (SUMD); other dimensions of insight could be studied.

CONCLUSION

Our results show that schizophrenia with preserved insight is associated with greater perfusion of the precuneus, a brain area known to be involved in self- consciousness, suggesting a compensatory mechanism of fronto-temporal impairment.

Symptom attribution in first episode psychosis: a cortical thickness study

One dimension of insight in psychosis is the ability to attribute correctly one's symptoms to a mental disorder. Recent work suggests that gray matter volumes of the orbitofrontal cortex (OFC) are correlated with aggregate symptom attribution scores in first-episode schizophrenia. Whether regions beyond the OFC are important for symptom attribution remains to be established. Further, whether common or separable neural systems underlie attribution of specific symptoms (e.g., delusions, asociality) has not been studied. In the current magnetic resonance imaging study, 52 people with a first-episode psychosis (FEP) were rated with the Scale for Assessment of Unawareness of Mental Disorder on attribution of hallucinations, delusions, flat affect and asociality. Attribution ratings were regressed on cortical thickness at 81,924 vertices. Mapping statistics revealed that delusion misattribution was associated with thickness in the OFC [Brodmann's area (BA) 11/47]. Delusion, flat affect and asociality misattribution were associated with cortical thinness in the dorsolateral prefrontal cortex (BA 9/46). Differential associations emerged between each attribution item and cortical thickness/thinness in a variety of frontal, temporal, parietal and occipital areas. The results imply a selective role for the OFC in delusion misattribution in FEP. Evidence for cortical thickness covariation in a variety of regions suggests partial independence in the neural architecture underlying attribution for different symptoms in FEP.

Insight in schizophrenia-course and predictors during the acute treatment phase of patients suffering from a schizophrenia spectrum disorder

BACKGROUND

To analyse insight of illness during the course of inpatient treatment, and to identify influencing factors and predictors of insight.

METHODS

Insight into illness was examined in 399 patients using the item G12 of the Positive and Negative Syndrome Scale ("lack of insight and judgement"). Ratings of the PANSS, HAMD, UKU, GAF, SOFAS, SWN-K and Kemp's compliance scale were performed and examined regarding their potential association with insight. The item G12 was kept as an ordinal variable to compare insight between subgroups of patients.

RESULTS

Almost 70% of patients had deficits in their insight into illness at admission. A significant improvement of impairments of insight during the treatment (p<0.0001) was observed. At admission more severe positive and negative symptoms, worse functioning and worse adherence were significantly associated with poorer insight. Less depressive symptoms (p=0.0004), less suicidality (p=0.0218), suffering from multiple illness-episodes (p<0.0001) and worse adherence (p=0.0012) at admission were identified to be significant predictors of poor insight at discharge.

CONCLUSION

The revealed predictors might function as treatment targets in order to improve insight and with it outcome of schizophrenia.

Cognitive decision modelling of emotion-based learning impairment in schizophrenia: the role of awareness

Individuals with schizophrenia often lack insight or awareness. Resulting impairment has been observed in various cognitive domains and, recently, linked to problems in emotion-based learning. The Iowa Gambling Task (IGT) has been used to assess emotion-based decision-making in patients with schizophrenia, but results have been inconclusive. The current study further investigates emotion-based decision-making in schizophrenia by elucidating the unique contribution of awareness. Twenty-five patients with schizophrenia and 24 healthy controls were assessed with a modified version of the IGT recording awareness at regular intervals. Symptom assessment, medication and medical history were recorded for the clinical group. Patients with schizophrenia underperformed on the IGT compared to controls. Subjective awareness levels were significantly lower in the schizophrenia group and were associated with hallucination severity. Cognitive decision modelling further indicated that patients with schizophrenia had impaired attention to losses, compared to controls. This parameter was positively correlated with awareness. We also found that positive symptoms altered awareness levels and suggest that this disruption may contribute to sub-optimal decision-making. Overall, a lack of awareness may be an important aspect in understanding impaired social cognitive functioning and emotion-based learning observed in schizophrenia.

Executive function on the Psychology Experiment Building Language tests

The measurement of executive function has a long history in clinical and experimental neuropsychology. The goal of the present report was to determine the profile of behavior across the lifespan on four computerized measures of executive function contained in the recently developed Psychology Experiment Building Language (PEBL) test battery http://pebl.sourceforge.net/ and evaluate whether this pattern is comparable to data previously obtained with the non-PEBL versions of these tests. Participants (N = 1,223; ages, 5-89 years) completed the PEBL Trail Making Test (pTMT), the Wisconsin Card Sort Test (pWCST; Berg, Journal of General Psychology, 39, 15-22, 1948; Grant & Berg, Journal of Experimental Psychology, 38, 404-411, 1948), the Tower of London (pToL), or a time estimation task (Time-Wall). Age-related effects were found over all four tests, especially as age increased from young childhood through adulthood. For several tests and measures (including pToL and pTMT), age-related slowing was found as age increased in adulthood. Together, these findings indicate that the PEBL tests provide valid and versatile new research tools for measuring executive functions.

Clinical and cognitive correlates of insight in first-episode schizophrenia

This study aims to explore the relationship between clinical symptoms and cognitive functions with different insight dimensions in patients with first-episode schizophrenia. Seventy-nine patients were assessed following six months of treatment. Insight was assessed using the abridged version of Scale of Unawareness of Mental Disorder (SUMD). Symptoms were assessed using Positive and Negative Syndrome Scale (PANSS). Cognitive functions were assessed using the Modified Wisconsin Card Sorting Test (MWCST), semantic verbal fluency and the letter-number sequencing (LNS) test from the Wechsler Adult Intelligence Scale (WAIS). Positive, negative and disorganized symptoms were found to be correlated with overall insight and all three general insight dimensions. Only perseverative errors and categories completed of MWCST were correlated with overall insight. Perseverative errors and non-perseverative errors of MWCST were correlated with the awareness of medication effects; perseverative errors of MWCST were also correlated with the awareness of social consequence of the illness. These support the link between poor insight and impaired executive function particularly measured by MWCST. The specific correlation of cognitive functions and different dimensions of insight suggests different underlying mechanism within each dimension of insight. The combined model of symptomatology and cognitive function explained 20.6% to 36.4% of the variance in the lack of insight within the different dimensions. The modest combined relationship of clinical and cognitive function with insight suggests that the exploration of other models in relationship to different insight dimensions is important.

Can children with ADHD be motivated to reduce bias in self-reports of competence?

OBJECTIVE

Our purpose in the current study was to examine whether children with attention-deficit/hyperactivity disorder (ADHD) and comparison children, if adequately motivated, are able to purposefully match their teachers' ratings of competence in multiple domains and whether any reductions in self-perceptual bias normalize self-views in relation to comparison children's self-perceptions.

METHOD

Participants included children with ADHD (n = 178) and comparison children (n = 86), between 7 and 12 years of age. The majority of participants were Caucasian (81.4%) and male (77.3%). Primary measures included the Self-Perception Profile for Children (SPPC; Harter, 1985), which was administered during a baseline assessment. In a subsequent session, children completed the SPPC twice more following instructions to first attempt to match their teachers' ratings of competence and then following the offer of an incentive for matching their teachers' ratings. Repeated measures analyses of covariance were conducted with between- and within-subjects factors.

RESULTS

Significant reductions in 2 of 3 domains (scholastic, behavioral conduct) were found for children with ADHD. No reductions were found across domains for comparison children or in the social domain for children with ADHD. Across conditions, the amount of bias exhibited by children with ADHD was never normalized in relation to comparison children's ratings.

CONCLUSIONS

Explicit instructions to match teacher ratings of competence and implementation of incentives were only partially effective in reducing the biased self-perceptions of children with ADHD. Results suggest that children with ADHD, on average, cannot view themselves in a completely unbiased fashion, rather than that they will not do so, although self-protection clearly plays a partial role.

The neuroanatomical correlates of cognitive insight in schizophrenia

Insight has been mostly studied from a clinical perspective. Recently, attention moved to cognitive insight or the ability to monitor and correct one's erroneous convictions. Here, we investigated the neuroanatomical correlates of cognitive insight. We administered the Beck cognitive insight scale to 45 outpatients with a schizophrenia diagnosis and 45 age- and gender-matched healthy control subjects who underwent a MRI investigation, including high-resolution volumetric and diffusion tensor imaging sequences. Gray and white matter volume, mean diffusivity and fractional anisotropy were used as dependent variables and were analyzed on a voxel-by-voxel basis with reference to the cognitive insight indexes. Self-reflectiveness was positively related to gray matter volume of the right ventro-lateral prefrontal cortex (VLPFC). No statistically significant results emerged from the DTI analyses, and no significant relationships were found for self-certainty and global cognitive insight. Reduced self-reflectiveness is related to a reduced volume of the VLPFC, an area involved in generating and maintaining in working memory different hypotheses about the self. This line of research focusing on the metacognitive features of insight in schizophrenia can provide relevant information to identify patients who are most vulnerable to lack of insight and develop effective cognitive therapeutic strategies.

The neuroanatomical correlates of cognitive insight in schizophrenia

Insight has been mostly studied from a clinical perspective. Recently, attention moved to cognitive insight or the ability to monitor and correct one's erroneous convictions. Here, we investigated the neuroanatomical correlates of cognitive insight. We administered the Beck cognitive insight scale to 45 outpatients with a schizophrenia diagnosis and 45 age- and gender-matched healthy control subjects who underwent a MRI investigation, including high-resolution volumetric and diffusion tensor imaging sequences. Gray and white matter volume, mean diffusivity and fractional anisotropy were used as dependent variables and were analyzed on a voxel-by-voxel basis with reference to the cognitive insight indexes. Self-reflectiveness was positively related to gray matter volume of the right ventro-lateral prefrontal cortex (VLPFC). No statistically significant results emerged from the DTI analyses, and no significant relationships were found for self-certainty and global cognitive insight. Reduced self-reflectiveness is related to a reduced volume of the VLPFC, an area involved in generating and maintaining in working memory different hypotheses about the self. This line of research focusing on the metacognitive features of insight in schizophrenia can provide relevant information to identify patients who are most vulnerable to lack of insight and develop effective cognitive therapeutic strategies.

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

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

Transient insight induction with electroconvulsive therapy in a patient with refractory schizophrenia: a case report and systematic literature review

Anosognosia or lack of illness awareness is a clinical manifestation of both schizophrenia and right hemispheric lesions associated with stroke, neurodegeneration, or traumatic brain injury. It is thought to result from right hemispheric dysfunction or interhemispheric disequilibrium, which provides a neuroanatomical model for illness unawareness in schizophrenia. Lack of insight contributes to medication nonadherence and poor treatment outcomes and is often refractory to pharmacological and psychological interventions. We present the first report of transient illness awareness (<8 hours) after individual bilateral electroconvulsive therapy treatments in the case of a 39-year-old man with antipsychotic refractory schizophrenia. Electroencephalography demonstrated frontal slow wave activity with shifting frontotemporal predominance, which was concurrent with the patient's transient level of insight. A systematic review of the literature on electroconvulsive therapy-induced illness awareness in schizophrenia and psychotic disorders produced zero relevant results. Future research should focus on the prospective role of focal interventions, such as transcranial magnetic stimulation, in the development of a neurophysiological model for anosognosia reversal in schizophrenia that may, in turn, contribute to novel therapeutic developments targeting lack of illness awareness.

Cognitive deficits and positively biased self-perceptions in children with ADHD

This study examined the relation between cognitive deficits and positive bias in a sample of 272 children with and without Attention Deficit Hyperactivity Disorder (ADHD; 7-12 years old). Results indicated that children with ADHD with and without biased self-perceptions exhibit differences in specific cognitive deficits (executive processes, working memory, broad attention, and cognitive fluency) compared to each other and to control children. Further, specific cognitive deficits emerged as partial mediators of the relation between ADHD diagnostic status and positive bias. Interestingly, some differences in results emerged based on the domain considered (academic, social, behavioral competence). Results lend initial support to the role of cognitive deficits in the positive bias of some children with ADHD. Implications for future research and intervention are discussed.

Association of VSNL1 with schizophrenia, frontal cortical function, and biological significance for its gene product as a modulator of cAMP levels and neuronal morphology

We report an association of single-nucleotide polymorphisms (SNPs) for the VSNL1 gene (visinin-like 1) with schizophrenia and frontal cortical function in a sample of patients with Diagnostic and Statistical Manual of Mental Disorder-IV (DSM-IV) diagnoses of schizophrenia, compared with healthy controls. Moreover, VSNL1 SNPs were associated with performance in the Wisconsin Card Sorting Test, a measure for the assessment of frontal cortical function. The VSNL1 gene product, Visinin-like-protein-1 (VILIP-1), is a member of the neuronal EF-hand Ca(2+)-sensor protein family. Previously, VILIP-1 mRNA and protein expression were shown to be altered in animal models and in schizophrenia patients. VILIP-1 influences cytosolic cyclic adenosine mono phosphate (cAMP) levels, cell migration, exocytotic processes and differentiation in the periphery. This raises the question, whether, similar to other potential schizophrenia susceptibility genes such as Disc1, PDE4B and Akt, VSNL1 may affect cAMP signaling and neurite outgrowth in neurons. In dissociated rat hippocampal neurons, VILIP-1 small interfering RNA knockdown decreased cAMP levels and reduced dendrite branching, compared with control-transfected cells. In contrast, VILIP-1 overexpression had the opposite effect. Similar results have been obtained in the human dopaminergic neuronal cell line SH-SY5Y, where the effect on neurite branching and length was attenuated by the adenylyl cyclase inhibitor 2',5'-dideoxyadenosine and the protein kinase A inhibitor KT5720. These results show that the association of VSNL1 SNPs with the disease and cognitive impairments, together with previously observed pathological changes in VILIP-1 protein expression, possibly occurring during brain development, may contribute to the morphological and functional deficits observed in schizophrenia.

Gray matter volume deficits and correlation with insight and negative symptoms in first-psychotic-episode subjects

OBJECTIVE

To determine brain areas reduced in first episode of psychotic subjects and its association with lack of insight and negative symptoms.

METHOD

Twenty-one drug naive first-episode subjects and 20 controls underwent a structural MRI scan and were clinically assessed. Optimized voxel-based-morphometry analysis (VBM) was implemented to find between-group differences and correlations between GM volume and: (i) lack of insight and (ii) negative symptoms.

RESULTS

Patients showed GM reduction in prefrontal and left temporal areas. A significant correlation was found between insight and GM volume in the cerebellum (corrected P = 0.01), inferior temporal gyrus (corrected P = 0.022), medial superior frontal gyrus (corrected P < 0.001), and inferior frontal gyrus (corrected P = 0.012), as the insight decreased, the volume decreased. Negative symptoms correlated with decreased GM volume at cerebellum (corrected P = 0.037) and frontal inferior regions (corrected P < 0.001), the more negative symptoms, the less volume.

CONCLUSION

Our findings support an association between prefrontal, temporal, and cerebellar deficits and lack of insight in schizophrenia and confirm previous findings of GM deficits in patients since the first episode of psychosis.

Insight dimensions in first-episode psychosis patients: clinical, cognitive, pre-morbid and socio-demographic correlates

AIM

To investigate pre-morbid, socio-demographic, clinical and cognitive variables as predictors of insight in a large and representative sample of first-episode psychosis patients.

METHODS

The abbreviated Scale to Assess Unawareness of Mental Disorder was used to assess insight dimensions. Patients with good and poor insight were independently compared on insight dimensions and logistic regression analyses were conducted to identify explanatory variables associated with each insight dimension.

RESULTS

The patients with good and poor insight of having a mental disorder differed in duration of untreated psychosis, diagnosis and attention, but only attention appeared as a predictor. The insight of the need for medication groups showed differences in age of onset, depression, severity of disorganized symptoms and hospitalization rate.Nevertheless, age of onset and disorganized symptoms seem to be the predictors. Groups of insight of the social consequences differed in duration of untreated psychosis, the negative and disorganized symptoms severity, disability, education, diagnosis and hospitalization rate.However, exclusively, the severity of disorganized symptoms seems to predict insight of social consequences.

CONCLUSION

When independently analysed, the three insight dimensions showed different rates of affectation and different predictors. These results suggest that there must be different mechanisms underlying the lack of insight. First-episode psychosis is a crucial period for treatment adherence formation, an issue strongly associated with good insight. Thus, a more accurate evaluation of the predictors of lack of insight into each dimension is warranted to achieve a better comprehension of the lack of insight in schizophrenia and in turn, to implement treatment programmes seeking to improve it.

White matter integrity and lack of insight in schizophrenia and schizoaffective disorder

OBJECTIVE

Poor insight into illness is commonly associated with schizophrenia and has implications for the clinical outcome of the disease. A better understanding of the neurobiology of these insight deficits may help the development of new treatments targeting insight. Despite the importance of this issue, the neural correlates of insight deficits in schizophrenia remain poorly understood.

METHOD

Thirty-six individuals diagnosed with schizophrenia or schizoaffective disorder underwent diffusion tensor imaging (DTI). The subjects were assessed on two dimensions of insight (symptom awareness and attribution of symptoms) using the Scale to Assess Unawareness of Mental Disorder (SUMD). Level of psychosis was assessed with the Positive and Negative Syndrome Scale (PANSS).

RESULTS

White matter abnormalities in the right superior frontal gyrus, left middle frontal gyrus, bilateral parahippocampal gyrus, adjacent to the right caudate head, right thalamus, left insula, left lentiform nucleus, left fusiform gyrus, bilateral posterior cingulate, left anterior cingulate, right cingulate gyrus, left lingual gyrus, and bilateral claustrum were associated with symptom unawareness. Misattribution of symptoms was related to deficits in the white matter adjacent to the right lentiform nucleus, left middle temporal gyrus, and the right precuneus.

CONCLUSIONS

Impaired insight in schizophrenia implicates a complex neural circuitry: white matter deficits in fronto-temporo brain regions are linked to symptom unawareness; compromised temporal and parietal white matter regions are involved in the misattribution of symptoms. These findings suggest the multidimensional construct of insight has multiple neural determinants.

Predictors of perceived need for medical care in an inpatient rehabilitation unit: an update

Limited awareness of illness, or poor insight, has been associated with poor treatment outcomes and prognoses in both psychiatric and medical populations. We examined predictors of insight in a sample of 403 patients in an inpatient rehabilitation unit at a Midwest Veterans Affairs Medical Center. A multiple regression analysis revealed that age, depression, IQ, and a measure of judgment were significant predictors of acknowledgement of illness. Younger age, higher IQ, better judgment, and depression were associated with better insight. By identifying risk factors for poor insight, these findings have significant clinical implications for healthcare providers.

Impaired insight in patients with newly diagnosed nonaffective psychotic disorders with and without deficit features

Patients with schizophrenia who have primary, enduring negative symptoms, or the deficit syndrome, have poorer psychosocial functioning but lesser clinical distress compared with nondeficit patients. Poor awareness of impairment in patients with deficit schizophrenia may contribute to this seeming contradiction. We hypothesized that poor insight would be present early in the course of illness in deficit patients, and that those with deficit features would have greater impairment in insight than those without deficit features. One-hundred one first-episode patients with nonaffective psychotic disorders were categorized into deficit (n=31) and nondeficit (n=70) groups. The deficit patients had significantly poorer insight than nondeficit patients when rated using a self-report questionnaire, and nearly significantly poorer insight rated by clinical researchers. Further, this effect remained for self-rated insight and reached statistical significance for researcher-rated insight after controlling for positive, negative, and general psychopathology symptoms. These results suggest that the treatment of deficit patients may be particularly complicated by poor insight.

Neurocognitive prediction of illness knowledge after psychoeducation in schizophrenia: results from the Munich COGPIP study

BACKGROUND

Many patients with schizophrenia exhibit neurocognitive impairments, namely, in attentional, mnestic and executive functions. While these deficits limit psychosocial rehabilitation, their effect on psychoeducation is unknown. Within the framework of the longitudinal Munich Cognitive Determinants of Psychoeducation and Information in Schizophrenic Psychoses (COGPIP) study, we examined: (a) whether illness knowledge after psychoeducation could be predicted more precisely from the neurocognitive than from the psychopathological status of the patients; (b) which neurocognitive domains are best predictors.

METHOD

A total of 116 in-patients with schizophrenic or schizoaffective disorders were randomized to a neurocognitive training or control condition (2 weeks) followed by a manualized psychoeducational group programme (4 weeks) and then observed over a 9-month follow-up. Repeated measurements included - among others - the Positive and Negative Syndrome Scale and a comprehensive neuropsychological test battery from which normative T scores were used to calculate one global and five domain-specific neurocognitive composite scores. Illness knowledge was measured by a questionnaire (WFB-52) tailored to the psychoeducational programme.

RESULTS

Multiple linear regression analyses showed that, apart from baseline illness knowledge, neurocognition significantly predicted knowledge outcome as well as knowledge gain (measured by reliable change indices) after psychoeducation. This was not true for psychopathology. Among the domain-specific neurocognitive composite scores, only memory acquisition was a significant predictor of knowledge outcome and gain.

CONCLUSIONS

Neurocognition, not psychopathology, is a significant predictor of illness knowledge after psychoeducation in schizophrenia. This finding should guide efforts to tailor psychoeducational interventions more closely to the patient's needs and resources.

Methamphetamine self-administration produces attentional set-shifting deficits and alters prefrontal cortical neurophysiology in rats

BACKGROUND

Chronic methamphetamine abusers exhibit deficits in tasks requiring intact prefrontal cortex function, and prefrontal cortex dysfunction has been implicated in the loss of control over drug use. This study used a combination of behavioral and electrophysiologic assessments in rats with a history of long access methamphetamine self-administration to determine methamphetamine-induced changes in prefrontal cortex-dependent attentional set-shifting performance, drug-seeking, and prefrontal cortex neuronal activity.

METHODS

Male Long-Evans rats self-administered methamphetamine (.02 mg/infusion, intravenous) or received yoked saline infusions for 6 hours a day for 14 days. Cognitive flexibility was assessed using an attentional set-shifting task before 2 weeks of self-administration and 1 day after self-administration. Animals then underwent 11 days of abstinence, followed by three subsequent tests for context-induced drug seeking. Finally, animals were anesthetized, and single-unit in vivo extracellular recordings were performed in the dorsomedial prefrontal cortex.

RESULTS

Methamphetamine-experienced rats showed escalated drug intake and context-induced drug-seeking following abstinence. During the extradimensional set-shift component, meth-experienced rats showed selective impairments that were identical to deficits produced by excitotoxic lesions of the prefrontal cortex. Rats with a history of chronic methamphetamine intake also exhibited higher basal firing frequency and a significantly greater proportion of burst-firing cells in the prefrontal cortex compared with yoked-saline controls.

CONCLUSIONS

Prefrontal cortex-specific alterations in neuronal function may play a key role in methamphetamine-induced attentional deficits and drug-seeking. These data support the possibility that targeting prefrontal cortex pathology may improve treatment outcome in methamphetamine addiction.

Trait and state attributes of insight in first episodes of early-onset schizophrenia and other psychoses: a 2-year longitudinal study

BACKGROUND

Increasing evidence supports the important role of illness state and individual characteristics in insight.

METHODS

Insight, as measured with the Scale to Assess Unawareness of Mental Disorder, over the first 2 years of early-onset first-episode psychosis and its correlations with clinical, socio-demographic, cognitive, and structural brain variables are studied.

RESULTS

(1) insight at 2 years is poorer in schizophrenia spectrum disorders (SSDs) than in subjects with other psychoses; (2) the more severe the psychosis, the worse the insight. In SSD, depressive symptoms, poorer baseline executive functioning, lower IQ, longer duration of untreated psychosis (DUP), and poorer premorbid infancy adjustment are associated with poorer insight; frontal and parietal gray matter (GM) reductions at baseline correlate with worse insight into having psychotic symptoms at 2 years; (3) insight into having a mental disorder (Scale to Assess Unawareness of Mental Disorder [SUMD]1) at 1 year, DUP, and baseline IQ are the most consistent variables explaining different aspects of insight at 2 years in SSD patients. IQ and SUMD1 at 1 year, together with left frontal and parietal GM volumes, explain 80% of the variance of insight into having specific psychotic symptoms in SSD patients (adjusted R(2) = 0.795, F = 15.576, P < .001).

CONCLUSION

Insight is a complex phenomenon that depends both on severity of psychopathology and also on disease and subject characteristics, such as past adjustment, IQ, DUP, cognitive functioning, frontal and parietal GM volumes, and age, gender, and ethnicity.

Toward a model of cognitive insight in first-episode psychosis: verbal memory and hippocampal structure

Our previous work has linked verbal learning and memory with cognitive insight, but not clinical insight, in individuals with a first-episode psychosis (FEP). The current study reassessed the neurocognitive basis of cognitive and clinical insight and explored their neural basis in 61 FEP patients. Cognitive insight was measured with the Beck Cognitive Insight Scale (BCIS) and clinical insight with the Scale to assess Unawareness of Mental Disorder (SUMD). Global measures for 7 domains of cognition were examined. Hippocampi were manually segmented in to 3 parts: the body, head, and tail. Verbal learning and memory significantly correlated with the BCIS composite index. Composite index scores were significantly associated with total left hippocampal (HC) volume; partial correlations, however, revealed that this relationship was attributable largely to verbal memory performance. The BCIS self-certainty subscale significantly and inversely correlated with bilateral HC volumes, and these associations were independent of verbal learning and memory performance. The BCIS self-reflectiveness subscale significantly correlated with verbal learning and memory but not with HC volume. No significant correlations emerged between the SUMD and verbal memory or HC volume. These results strengthen our previous assertion that in individuals with an FEP cognitive insight may rely on memory whereby current experiences are appraised based on previous ones. The HC may be a viable location among others for the brain system that underlies aspects of cognitive insight in individuals with an FEP.

Subjective awareness of tardive dyskinesia and insight in schizophrenia

BACKGROUND

Lack of awareness of tardive dyskinesia (TD) and poor insight into mental illness are common in schizophrenia, raising the possibility that these phenomena are manifestations of a common underlying dysfunction.

METHODS

We investigated relationships between low awareness of TD and poor insight into mental illness in 130 patients with schizophrenia and TD. We also examined selected demographic and clinical correlates of these two phenomena.

RESULTS

Sixty-six (51%) patients had no or low awareness of TD and 94 (72%) had at least mild impairment of insight into their mental illness. Low awareness of TD was not significantly correlated with greater impairment of insight into mental illness. Regression analyses indicated that the Positive and Negative Syndrome Scale (PANSS) disorganised factor (β=0.72, t=11.88, p<0.01) accounted for 52% of the variance in insight into mental illness (adjusted R(2)=0.55) (F[2, 127]=81.00, p<0.01) and the Extrapyramidal Symptom Rating Scale (ESRS) dyskinesia subscale score (β=0.47, t=6.80, p<0.01), PANSS disorganised factor (β=-0.26, t=-3.73, p<0.01), and ESRS parkinsonism subscale score (β=0.31, t=4.55, p<0.01) together accounted for 37% of the variance in awareness of TD (adjusted R(2)=0.37) (F[3, 126]=26.87, p<0.01).

CONCLUSION

The two phenomena appear to be dissociated, and may be domain-specific.

Neuropsychological correlates of cognitive insight in schizophrenia

Clinical practice has highlighted a possible discrepancy between patient's verbal assertions, called clinical insight, and the actual convictions about the illness, called emotional insight. The complementary construct of cognitive insight refers to the cognitive processes involved in self-reflection and the ability to modify erroneous beliefs and misinterpretations. The aim of this study was to determine the psychopathological and neuropsychological predictors of cognitive insight in schizophrenia. Sixty outpatients with Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) schizophrenia diagnosis were administered the Beck Cognitive Insight Scale, the Positive and Negative Symptom Scale (PANSS), and a comprehensive neuropsychological battery. Results indicate that poor global cognitive insight in schizophrenia is significantly related to lower visual working memory, while a higher self-overconfidence is significantly related to deficits in verbal and visual memory and to the failure in using external information to correct erroneous convictions. Thus, our study suggests that impaired cognitive insight depends mainly on reduced working memory and executive function performances. These findings highlight the fundamental importance of the development of specific therapeutic strategies to improve the metacognitive components of insight in order to enhance treatment adherence in schizophrenia.

Diminished humour perception in schizophrenia: relationship to social and cognitive functioning

This study attempted to confirm that humour recognition deficits previously found in schizophrenia are specific to the condition and not attributable to other parameters such as depression or anxiety. Secondarily, we explored any possible cognitive or social functioning correlates to humour recognition deficits. A total of 60 participants (20 outpatients with schizophrenia, 20 psychiatric control participants and 20 control participants) underwent a 64-question humour task in addition to a battery of standard cognitive tests and Social Functioning Scales. In order to compare the three groups of participants, we conducted an analysis of variance (ANOVA) and post-hoc t-tests on neuropsychological measures, social functioning measures, and the primary outcome, humour recognition. The schizophrenia group showed significant and substantial deficits in humour recognition compared to the healthy control group, t(38)=5.1, P<0.001, ES=-1.55 and the psychiatric control group, t(38)=3.6, P=0.001. In the schizophrenia group, humour recognition correlated positively with general intellectual functioning (NART) r=.45, P=0.04, social reasoning (WAIS-III Comprehension) r=.54, P=0.01, executive functioning (WCST-CC) r=.69, P=0.001 and social adjustment ratings (SASS scores), r=.54, P=0.02. These findings support the assertion that humour recognition deficits in schizophrenia are specific to the condition and not attributable to other factors such as depression or anxiety. Furthermore, humour recognition deficits in schizophrenia may perhaps be preferentially associated with deficiencies in set shifting and semantic cognition.

Longitudinal alterations of executive function in non-psychotic adolescents at familial risk for schizophrenia

Genetic diathesis to schizophrenia may involve alterations of adolescent neurodevelopment manifesting as cognitive deficits. Brain regions mediating executive function (fronto-striatal circuits) develop during adolescence while those supporting elementary aspects of attention (e.g. sustained focused attention) have a more protracted maturation beginning in childhood. We hence predicted that adolescents at risk for schizophrenia would show a failure of normal maturation of executive function. We prospectively assessed 18 offspring and 6 siblings of schizophrenia patients (HR) and 28 healthy controls at baseline, year-1 and year-2 follow-up using the Continuous Performance Test [visual-d'] and Wisconsin Card Sort Test (WCST). Perseverative errors on the WCST in HR remained stable but decreased in controls over the follow-up (study-group by assessment-time interaction, p=0.01, controlling for IQ). No significant study-group by assessment-time interactions were seen for sustained attentional performance. HR may not improve while healthy subjects progressively improve on executive function during adolescence and early adulthood. Our results suggest an altered maturational trajectory of executive function during adolescence in individuals at familial risk for schizophrenia.

Association between genetic variants of the metabotropic glutamate receptor 3 (GRM3) and cognitive set shifting in healthy individuals

Set-shifting and maintenance are complex cognitive processes, which are often impaired in schizophrenia. The genetic basis of these processes is poorly understood. We aimed to investigate the association between genetic variants of the metabotropic glutamate receptor 3 (GRM3) and cognitive set-shifting in healthy individuals. The relationship between 14 selected single nucleotide polymorphisms (SNPs) of the GRM3 gene and cognitive set-shifting as measured by perseverative errors using the modified card sorting test (MCST) was analysed in a sample of N = 98 young healthy individuals (mean age in years: 22.7 +/- 0.19). Results show that SNP rs17676277 is related to the performance on the MCST. Subjects with the TT genotype showed significantly less perseverative errors as compared with the AA (P = 0.025) and AT (P = 0.0005) and combined AA/AT genotypes (P = 0.0005). Haplotype analyses suggest the involvement of various SNPs of the GRM3 gene in perseverative error processing in a dominant model of inheritance. The findings strongly suggest that the genetic variation (rs17676277 and three haplotypes) in the metabotropic GRM3 is related to cognitive set-shifting in healthy individuals independent of working memory. However, because of a relatively small sample size for a genetic association study, the present results are tentative and require replication.

Do individuals with schizophrenia and a borderline intellectual disability benefit from psychoeducational groups?

Studies on psychoeducation in schizophrenia demonstrate significant effects on rehospitalization rates, compliance and knowledge. Within the framework of the Munich COGPIP study we examined whether borderline intellectual disability in patients with schizophrenia limits the benefit from psychoeducational groups. A total of 116 inpatients with schizophrenic or schizoaffective disorders were recruited for the COGPIP study. A manualized, interactive psychoeducational programme of eight sessions (4 weeks) was initiated. Measures of knowledge, adherence and the concept of illness were completed before and after the groups. The short-term outcome of 22 participants with schizophrenia and borderline intellectual disability (IQ 70-85) was compared with the outcome of 75 participants with schizophrenia and IQ > 85. Results showed that individuals with schizophrenia and borderline intellectual disability could be successfully integrated into general psychoeducational groups. The conclusion is that borderline intellectual disability should not be an exclusion criterion for participation in such groups.

Schizophrenia; from structure to function with special focus on the mediodorsal thalamic prefrontal loop

OBJECTIVE

To describe structural and biochemical evidence from postmortem brains that implicates the reciprocal connections between the mediodorsal thalamic nucleus and the prefrontal cortex in cognitive symptoms of schizophrenia.

METHOD

The estimation of the regional volumes and cell numbers was obtained using stereological methods. The biochemical analyses of molecular expression in postmortem brain involve quantitative measurement of transcripts and proteins by in-situ (RNA) or Western blot/autoradiography in brains from patients with schizophrenia and comparison subjects.

RESULTS

Stereological studies in postmortem brain from patients with schizophrenia have reported divergent and often opposing findings in the total number of neurons and volume of the mediodorsal (MD) thalamic nucleus, and to a lesser degree in its reciprocally associated areas of the prefrontal cortex. Similarly, quantitative molecular postmortem studies have found large inter-subject and between-study variance at both the transcript and protein levels for receptors and their interacting molecules of several neurotransmitter systems in these interconnected anatomical regions. Combined, large variation in stereological and molecular studies indicates a complex and heterogeneous involvement of the MD thalamic-prefrontal loop in schizophrenia.

CONCLUSION

Based on a considerable heterogeneity in patients suffering from schizophrenia, large variation in postmortem studies, including stereological and molecular postmortem studies of the MD thalamus and frontal cortex, might be expected and may in fact partly help to explain the variable endophenotypic traits associated with this severe psychiatric illness.

Specific metabolites in the medial prefrontal cortex are associated with the neurocognitive deficits in schizophrenia: a preliminary study

We measured brain metabolites in the medial prefrontal cortex of 19 schizophrenic patients and 18 healthy controls by 3 T proton magnetic resonance spectroscopy ((1)H MRS), and examined the relationship between prefrontal cortex-related neurocognitive functions and brain metabolites in the medial prefrontal cortex. The patients with schizophrenia exhibited deficits on the verbal fluency, Wisconsin card sorting test (WCST), trail making test, Stroop test and digit span distraction test (DSDT), but not on the Iowa gambling test. The patients showed statistical significant changes in the ratio of glutamine/glutamate, the ratio of N-acetyl-l-aspartate (NAA)/glycerophosphorylcholine plus phosphorylcholine (GPC+PC) and the levels of taurine in the medial prefrontal cortex compared with normal controls. Furthermore, we found significant correlations of the ratio of glutamine/glutamate with WCST and DSDT scores, the ratio of NAA/(GPC+PC) with verbal fluency and WCST scores, and the levels of taurine with scores on the Stroop test and Trail making test A among the participants. The ratios of NAA/(GPC+PC) and (GPC+PC)/(Cr+PCr) had significant relationships with the duration of untreated psychosis of the schizophrenic patients. The glutamine/glutamate ratio and levels of taurine were significantly related to the duration of illness of the patients. These data suggest that specific metabolites of the medial prefrontal cortex are associated with the neurocognitive deficits in schizophrenia.

What do we know about neuropsychological aspects of schizophrenia?

Application of a neuropsychological perspective to the study of schizophrenia has established a number of important facts about this disorder. Some of the key findings from the existing literature are that, while neurocognitive impairment is present in most, if not all, persons with schizophrenia, there is both substantial interpatient heterogeneity and remarkable within-patient stability of cognitive function over the long-term course of the illness. Such findings have contributed to the firm establishment of neurobiologic models of schizophrenia, and thereby help to reduce the social stigma that was sometimes associated with purely psychogenic models popular during parts of the 20th century. Neuropsychological studies in recent decades have established the primacy of cognitive functions over psychopathologic symptoms as determinants of functional capacity and independence in everyday functioning. Although the cognitive benefits of both conventional and even second generation antipsychotic medications appear marginal at best, recognition of the primacy of cognitive deficits as determinants of functional disability in schizophrenia has catalyzed recent efforts to develop targeted treatments for the cognitive deficits of this disorder. Despite these accomplishments, however, some issues remain to be resolved. Efforts to firmly establish the specific neurocognitive/neuropathologic systems responsible for schizophrenia remain elusive, as do efforts to definitively demonstrate the specific cognitive deficits underlying specific forms of functional impairment. Further progress may be fostered by recent initiatives to integrate neuropsychological studies with experimental neuroscience, perhaps leading to measures of deficits in cognitive processes more clearly associated with specific, identifiable brain systems.

Reduced insight in bipolar I disorder: neurofunctional and neurostructural correlates: a preliminary study

BACKGROUND

To correlate measures of insight for own psychopathology to structural and functional brain imaging findings in 21 patients with DSM-IV bipolar I disorder.

METHODS

Insight was assessed using the Scale to Assess Unawareness of Mental Disorder (SUMD). Resting single photon emission computed tomography (SPECT) and computed tomography (CT) was conducted in patients and 21 normal comparison subjects matched for age, gender and handedness.

RESULTS

Reduced general insight and symptom awareness, but not symptom attribution, were significantly related to cortical and subcortical atrophy, respectively. No correlations between SPECT and insight measures were identified.

LIMITATIONS

Limited sample size and the use of resting state SPECT.

CONCLUSIONS

General and symptom awareness were related to measures of brain atrophy but not to neurofunctioning as measured by SPECT. Future research should consider the structure and function of specific cortical regions, including the frontal and parietal cortices.

Insight and executive functioning in schizophrenia: a multidimensional approach

Past research suggests that unawareness of illness in schizophrenia is associated with deficits in executive functions; however, the relationships between executive processes and the various dimensions of insight are still unclear. Recent models of executive functioning have proposed that four executive processes - inhibition, updating, shifting and dual task coordination - are moderately related yet separable. In this study, we proposed to investigate and clarify the relationships between insight dimensions and the aforementioned four executive components. A total of 60 patients were administered the Test for Attentional Performance and the Scale to Assess Unawareness of Mental Disorder. The effect of potential confounding variables such as medication, symptomatology, demography, psycho-affective state, and general processing speed were also examined in a preliminary statistical analysis. We found that both awareness of disorder and awareness of response to medication were significantly related to Updating. Awareness of the social consequences of the disease was significantly related to Updating, Divided Attention and Inhibition Processes. The analysis indicates that poor insight in schizophrenia may be partially related to executive dysfunction. Finally, our study emphasizes the possible role of neuropsychological intervention in improving patients' insight into illness.

Schizophrenia, "just the facts" 4. Clinical features and conceptualization

Although dementia praecox or schizophrenia has been considered a unique disease entity for the past century, its definitions and boundaries have continued to vary over this period. At any given time, the changing concept of schizophrenia has been influenced by available diagnostic tools and treatments, related conditions from which it most needs to be distinguished, extant knowledge and scientific paradigms. There is significant heterogeneity in the etiopathology, symptomatology, and course of schizophrenia. It is characterized by an admixture of positive, negative, cognitive, mood, and motor symptoms whose severity varies across patients and through the course of the illness. Positive symptoms usually first begin in adolescence or early adulthood, but are often preceded by varying degrees of negative and cognitive symptomatology. Schizophrenia tends to be a chronic and relapsing disorder with generally incomplete remissions, variable degrees of functional impairment and social disability, frequent comorbid substance abuse, and decreased longevity. Although schizophrenia may not represent a single disease with a unitary etiology or pathogenetic process, alternative approaches have thus far been unsuccessful in better defining this syndrome or its component entities. The symptomatologic, course, and etio-pathological heterogeneity can usefully be addressed by a dimensional approach to psychopathology, a clinical staging approach to illness course, and by elucidating endophenotypes and markers of illness progression, respectively. This will allow an approach to the deconstruction of schizophrenia into its multiple component parts and strategies to reconfigure these components in a more meaningful manner. Possible implications for DSM-V and ICD-11 definitions of schizophrenia are discussed.