Specific frontal lobe subregions correlated with unawareness of illness in schizophrenia: a preliminary study

Cortical thinning in relation to impaired insight into illness in patients with treatment resistant schizophrenia

Impaired insight into illness is a common element of schizophrenia that contributes to treatment nonadherence and negative clinical outcomes. Previous studies suggest that impaired insight may arise from brain abnormalities. However, interpretations of these findings are limited due to small sample sizes and inclusion of patients with a narrow range of illness severity and insight deficits. In a large sample of patients with schizophrenia, the majority of which were designated as treatment-resistant, we investigated the associations between impaired insight and cortical thickness and subcortical volumes. A total of 94 adult participants with a schizophrenia spectrum disorder were included. Fifty-six patients (60%) had treatment-resistant schizophrenia. The core domains of insight were assessed with the VAGUS insight into psychosis scale. We obtained 3T MRI T1-weighted images, which were analysed using CIVET and MAGeT-Brain. Whole-brain vertex-wise analyses revealed impaired insight, as measured by VAGUS average scores, was related to cortical thinning in left frontotemporoparietal regions. The same analysis in treatment-resistant patients showed thinning in the same regions, even after controlling for age, sex, illness severity, and chlorpromazine antipsychotic dose equivalents. No association was found in non-treatment-resistant patients. Region-of-interest analyses revealed impaired general illness awareness was associated with cortical thinning in the left supramarginal gyrus when controlling for covariates. Reduced right and left thalamic volumes were associated with VAGUS symptom attribution and awareness of negative consequences subscale scores, respectively, but not after correction for multiple testing. Our results suggest impaired insight into illness is related to cortical thinning in left frontotemporoparietal regions in patients with schizophrenia, particularly those with treatment resistance where insight deficits may be more chronic.

Structural brain abnormalities in schizophrenia patients with a history and presence of auditory verbal hallucination

Although many studies have demonstrated structural brain abnormalities associated with auditory verbal hallucinations (AVH) in schizophrenia, the results remain inconsistent because of the small sample sizes and the reliability of clinical interviews. We compared brain morphometries in 204 participants, including 58 schizophrenia patients with a history of AVH (AVH + ), 29 without a history of AVH (AVH-), and 117 healthy controls (HCs) based on a detailed inspection of medical records. We further divided the AVH+ group into 37 patients with and 21 patients without hallucinations at the time of the MRI scans (AVH++ and AVH+-, respectively) via clinical interviews to explore the morphological differences according to the persistence of AVH. The AVH + group had a smaller surface area in the left caudal middle frontal gyrus (F = 7.28, FDR-corrected p = 0.0008) and precentral gyrus (F = 7.68, FDR-corrected p = 0.0006) compared to the AVH- group. The AVH+ patients had a smaller surface area in the left insula (F = 7.06, FDR-corrected p = 0.001) and a smaller subcortical volume in the bilateral hippocampus (right: F = 13.34, FDR-corrected p = 0.00003; left: F = 6.80, FDR-corrected p = 0.001) compared to the HC group. Of these significantly altered areas, the AVH++ group showed significantly smaller bilateral hippocampal volumes compared to the AVH+- group, and a smaller surface area in the left precentral gyrus and caudal middle frontal gyrus compared to the AVH- group. Our findings highlighted the distinct pattern of structural alteration between the history and presence of AVH in schizophrenia, and the importance of integrating multiple criteria to elucidate the neuroanatomical mechanisms.

Relationships between cognitive performance, clinical insight and regional brain volumes in schizophrenia

Impairments in cognitive performance are common in schizophrenia, and these contribute to poor awareness of symptoms and treatment (‘clinical insight’), which is an important predictor of functional outcome. Although relationships between cognitive impairment and reductions in regional brain volumes in patients are relatively well characterised, less is known about the brain structural correlates of clinical insight. To address this gap, we aimed to explore brain structural correlates of cognitive performance and clinical insight in the same sample. 108 patients with schizophrenia (SZH) and 94 age and gender-matched controls (CON) (from the Northwestern University Schizophrenia Data and Software Tool (NUSDAST) database) were included. SZH had smaller grey matter volume across most fronto-temporal regions and significantly poorer performance on all cognitive domains. Multiple regression showed that higher positive symptoms and poorer attention were significant predictors of insight in SZH; however, no significant correlations were seen between clinical insight and regional brain volumes. In contrast, symptomology did not contribute to cognitive performance, but robust positive relationships were found between regional grey matter volumes in fronto-temporal regions and cognitive performance (particularly executive function). Many of these appeared to be unique to SZH as they were not observed in CON. Findings suggest that while there exists a tight link between cognitive functioning and neuropathological processes affecting gross brain anatomy in SZH, this is not the case for clinical insight. Instead, clinical insight levels seem to be influenced by symptomology, attentional performance and other subject-specific variables.

Anosognosia in moderate-to-severe traumatic brain injury: A review of prevalence, clinical correlates, and diversity considerations

METHOD

A comprehensive search of peer-reviewed articles was conducted from September to November 2020 using Google Scholar and PubMed databases. Key terms included "anosognosia," "self-awareness," "traumatic brain injury," and variants thereof. Our search was restricted to articles published in English within the last 25 years, although a few historical articles were included due to scientific merit. Articles were chosen based on methodological quality, inclusion of solely or predominantly msevTBI sample, and relevance to the current topic.

CONCLUSIONS

Anosognosia is a multifaceted and domain-specific construct that affects the majority of those with msevTBI. It is related to TBI severity, injuries in right-hemispheric and cortical midline regions, specific aspects of executive function, psychological function, and cultural factors. We offer pragmatic advice for clinicians working with this population and discuss implications for the field regarding "best practices" of anosognosia assessment and intervention.

Neuroimaging correlates of insight in non-affective psychosis: A systematic review and meta-analysis

OBJECTIVE

Neurological correlates of impaired insight in non-affective psychosis remain unclear. This study aimed to review and meta-analyze the studies assessing the grey matter volumetric correlates of impaired insight in non-affective psychosis.

METHODS

This study consisted of a systematic review of 23 studies, and a meta-analysis with SDM-PSI of the 11 studies that were whole-brain and reported maps or peaks of correlation of studies investigating the grey matter volumetric correlates of insight assessments of non-affective psychosis, PubMed and OVID datasets were independently reviewed for articles reporting neuroimaging correlates of insight in non-affective psychosis. Quality assessment was realized following previous methodological approaches for the ABC quality assessment test of imaging studies, based on two main criteria: the statistical power and the multidimensional assessment of insight. Study peaks of correlation between grey matter volume and insight were used to recreate brain correlation maps.

RESULTS

A total of 418 records were identified through database searching. Of these records, twenty-three magnetic resonance imaging (MRI) studies that used different insight scales were included. The quality of the evidence was high in 11 studies, moderate in nine, and low in three. Patients with reduced insight showed decreases in the frontal, temporal (specifically in superior temporal gyrus), precuneus, cingulate, insula, and occipital lobes cortical grey matter volume. The meta-analysis indicated a positive correlation between grey matter volume and insight in the right insula (i.e., the smaller the grey matter, the lower the insight).

CONCLUSION

Several brain areas might be involved in impaired insight in patients with non-affective psychoses. The methodologies employed, such as the applied insight scales, may have contributed to the considerable discrepancies in the findings.

Neuroimaging correlates of insight in non-affective psychosis: A systematic review and meta-analysis

OBJECTIVE

Neurological correlates of impaired insight in non-affective psychosis remain unclear. This study aimed to review and meta-analyze the studies assessing the grey matter volumetric correlates of impaired insight in non-affective psychosis.

METHODS

This study consisted of a systematic review of 23 studies, and a meta-analysis with SDM-PSI of the 11 studies that were whole-brain and reported maps or peaks of correlation of studies investigating the grey matter volumetric correlates of insight assessments of non-affective psychosis, PubMed and OVID datasets were independently reviewed for articles reporting neuroimaging correlates of insight in non-affective psychosis. Quality assessment was realized following previous methodological approaches for the ABC quality assessment test of imaging studies, based on two main criteria: the statistical power and the multidimensional assessment of insight. Study peaks of correlation between grey matter volume and insight were used to recreate brain correlation maps.

RESULTS

A total of 418 records were identified through database searching. Of these records, twenty-three magnetic resonance imaging (MRI) studies that used different insight scales were included. The quality of the evidence was high in 11 studies, moderate in nine, and low in three. Patients with reduced insight showed decreases in the frontal, temporal (specifically in superior temporal gyrus), precuneus, cingulate, insula, and occipital lobes cortical grey matter volume. The meta-analysis indicated a positive correlation between grey matter volume and insight in the right insula (i.e., the smaller the grey matter, the lower the insight).

CONCLUSION

Several brain areas might be involved in impaired insight in patients with non-affective psychoses. The methodologies employed, such as the applied insight scales, may have contributed to the considerable discrepancies in the findings.

Exploring the relationship between impaired illness awareness and visuospatial inattention in patients with schizophrenia

Anosognosia, described as impairment in an individual's ability to perceive and understand their illness, and visuospatial inattention commonly co-occur as a result of structural brain lesions in the right posterior parietal area. Anosognosia or impaired illness awareness is a common feature of schizophrenia that contributes to medication nonadherence and poor clinical outcomes. A recent pilot study suggests patients with impaired illness awareness have a rightward visuospatial bias. We aimed to examine this relationship in a large sample of patients. This study consisted of 106 patients with schizophrenia spectrum disorder (henceforth, schizophrenia) and 20 healthy controls. Visuospatial attention was assessed using the line bisection test (LBT). Illness awareness was assessed using the VAGUS self-report version. A Welch's t-test was used to examine differences in LBT scores between patients with schizophrenia and healthy controls. Correlation analyses between LBT and VAGUS scores were performed in patients with schizophrenia. For exploratory purposes, intra-subject reliability of the LBT was also examined using a two-way mixed intra-class correlation coefficient (ICC). There were no differences in LBT scores between patients with schizophrenia and healthy controls. In patients, there were no associations between LBT and VAGUS scores. ICCs between two consecutively acquired LBTs were 0.92 (95% CI: 0.81-0.96) in patients with schizophrenia and 0.93 (95% CI: 0.81-0.97) in healthy controls. Our results, using a reliable measure, did not support our previous preliminary finding that suggested a relationship between impaired illness awareness and visuospatial bias in patients with schizophrenia. Future studies should consider more sensitive visuospatial attention tasks when testing this hypothesis.

Brain areas associated with clinical and cognitive insight in psychotic disorders: A systematic review and meta-analysis

In the past years, ample interest in brain abnormalities related to clinical and cognitive insight in psychosis has contributed several neuroimaging studies to the literature. In the current study, published findings on the neural substrates of clinical and cognitive insight in psychosis are integrated by performing a systematic review and meta-analysis. Coordinate-based meta-analyses were performed with the parametric coordinate-based meta-analysis approach, non-coordinate based meta-analyses were conducted with the metafor package in R. Papers that could not be included in the meta-analyses were systematically reviewed. Thirty-seven studies were retrieved, of which 21 studies were included in meta-analyses. Poorer clinical insight was related to smaller whole brain gray and white matter volume and gray matter volume of the frontal gyri. Cognitive insight was predominantly positively associated with structure and function of the hippocampus and ventrolateral prefrontal cortex. Impaired clinical insight is not associated with abnormalities of isolated brain regions, but with spatially diffuse global and frontal abnormalities suggesting it might rely on a range of cognitive and self-evaluative processes. Cognitive insight is associated with specific areas and appears to rely more on retrieving and integrating self-related information.

The Relation Between Empathy and Insight in Psychiatric Disorders: Phenomenological, Etiological, and Neuro-Functional Mechanisms

Lack of insight, i.e., unawareness of one's mental illness, is frequently encountered in psychiatric conditions. Insight is the capacity to recognize (psychical insight) and accept one's mental illness (emotional insight). Insight growth necessitates developing an objective perspective on one's subjective pathological experiences. Therefore, insight has been posited to require undamaged self-reflexion and cognitive perspective-taking capacities. These enable patients to look objectively at themselves from the imagined perspective of someone else. Preserved theory-of-mind performances have been reported to positively impact insight in psychosis. However, some patients with schizophrenia or obsessive-compulsive disorders, although recognizing their mental disease, are still not convinced of this and do not accept it. Hence, perspective-taking explains psychical insight (recognition) but not emotional insight (acceptance). Here, we propose a new conceptual model. We hypothesize that insight growth relies upon the association of intact self-reflexion and empathic capacities. Empathy (feeling into someone else) integrates heterocentered visuo-spatial perspective (feeling into), embodiment, affective (feeling into) and cognitive processes, leading to internally experience the other's thought. We posit that this subjective experience enables to better understand the other's thought about oneself and to affectively adhere to this. We propose that the process of objectification, resulting from empathic heterocentered, embodiment, and cognitive processes, generates an objective viewpoint on oneself. It enables to recognize one's mental illness and positively impacts psychical insight. The process of subjectification, resulting from empathic affective processes, enables to accept one's illness and positively impacts emotional insight. That is, affectively experiencing the thought of another person about oneself reinforces the adhesion of the emotional system to the objective recognition of the disease. Applying our model to different psychiatric disorders, we predict that the negative effect of impaired self-reflexion and empathic capacities on insight is a transnosographic state and that endophenotypical differences modulate this common state, determining a psychiatric disease as specific.

Associations of cortical thickness, surface area and subcortical volumes with insight in drug-naïve adults with obsessive-compulsive disorder

• We first used the SBM method to explore the neuroanatomical basis underlying insight in OCD.

• OCD-GI and OCD-PI displayed mostly shared, but partly distinct brain structural alterations.

• Decreased cortical thickness in the left dmPFC, the left ACC and the right lateral parietal cortex was associated with poorer insight.

• The potential effect of other clinical variables on the results has been ruled out.

Poor insight in obsessive-compulsive disorder (OCD) is associated with several adverse clinical outcomes. However, the neurobiological basis of this insight deficit is not clearly understood. The present study thus aimed to investigate associations of cortical thickness, cortical surface area and subcortical volumes with insight in a sample of drug-naïve adults with OCD. Forty-seven OCD patients and 42 healthy controls (HCs) underwent MRI scanning, depression and anxiety assessments. The Brown Assessment of Beliefs Scale (BABS) measured insight levels and patients were divided into two groups: poor insight (OCD-PI; n = 21), and good insight (OCD-GI; n = 26). Cortical thickness and surface area between groups were compared with whole-brain exploratory vertex-by-vertex analyses, while subcortical volumes were compared on a structure-by-structure basis. Partial correlation analyses were then performed to assess associations between regional cortical and subcortical measures and insight levels. OCD-GI and OCD-PI groups displayed partly shared, but also partly distinct brain structural alterations. Strikingly, OCD-PI showed decreased cortical thickness in the left superior frontal gyrus, left anterior cingulate cortex (ACC) and right inferior parietal gyrus, compared to both OCD-GI and HCs. Average cortical thickness extracted from these areas was further negatively correlated with BABS scores in the OCD-PI patients. Our findings suggest that poor insight in patients with OCD may have a neural substrate involving the left medial frontal and the right inferior parietal cortices.

Clarifying associations between cortical thickness, subcortical structures, and a comprehensive assessment of clinical insight in enduring schizophrenia

BACKGROUND

The relationship between poor insight and less favorable outcomes in schizophrenia has promoted research efforts to understand its neurobiological basis. Thus far, research on neural correlates of insight has been constrained by small samples, incomplete insight assessments, and a focus on frontal lobes. The purpose of this study was to examine associations of cortical thickness and subcortical volumes, with a comprehensive assessment of clinical insight, in a large sample of enduring schizophrenia patients.

METHODS

Two dimensions of clinical insight previously identified by a factor analysis of 4 insight assessments were used: Awareness of Illness and Need for Treatment (AINT) and Awareness of Symptoms and Consequences (ASC). T1-weighted structural images were acquired on a 3 T MRI scanner for 110 schizophrenia patients and 69 healthy controls. MR images were processed using CIVET (version 2.0) and MAGeT and quality controlled pre and post-processing. Whole-brain and region-of-interest, vertex-wise linear models were applied between cortical thickness, and levels of AINT and ASC. Partial correlations were conducted between volumes of the amygdala, thalamus, striatum, and hippocampus and insight levels.

RESULTS

No significant associations between both insight factors and cortical thickness were observed. Moreover, no significant associations emerged between subcortical volumes and both insight factors.

CONCLUSIONS

These results do not replicate previous findings obtained with smaller samples using single-item measures of insight into illness, suggesting a limited role of neurobiological factors and a greater role of psychological processes in explaining levels of clinical insight.

Self-Awareness of Psychopathology and Brain Volume in Patients With First Episode Psychosis

Memory impairment, excessive rumination, and increased interpersonal sensitivity are major characteristics of high psychosis risk or first episode psychosis (FEP). Herein, we investigated the relationship between brain volume and self-awareness of psychopathology in patients with FEP. All participants (FEP: 34 and HCs: 34) completed clinical assessments and the following self-reported psychopathology evaluations: prospective and retrospective memory questionnaire (PRMQ), ruminative response scale (RRS), and interpersonal sensitivity measure (IPSM). Structural magnetic resonance imaging was then conducted. The PRMQ, RRS, and IPSM scores were significantly higher in the FEP group than in the healthy controls (HCs). The volumes of the amygdala, hippocampus, and superior temporal gyrus (STG) were significantly lower in the FEP group than in the HCs. There was a significant group-dependent moderation effect between self-awareness of psychopathology (PRMQ, RRS, and IPSM scores) and right STG (rSTG) volume. In the FEP group, self-awareness of psychopathology was positively associated with rSTG volume, while in the HCs, this correlation was negative. Our results indicate that self-awareness of psychopathology impacts rSTG volume in the opposite direction between patients with FEP and HCs. In patients with FEP, awareness of impairment may induce increases in rSTG brain volume. However, HCs showed decreased rSTG volume when they were aware of impairment.

Symptom attribution and frontal cortical thickness in first-episode schizophrenia

AIM

Misattribution of symptoms is a common feature of schizophrenia, and likely involves impairment of metacognitive function that may be mediated by the frontal cortex. We aimed to compare frontal cortical thickness in first-episode schizophrenia (FES) patients with matched controls, and investigate its relationship with the symptom attribution dimension of insight in FES patients.

METHODS

We examined frontal cortical thickness in 92 minimally treated FES patients at baseline presentation and 93 healthy controls aged 16-45 years. We examined for correlations between symptom attribution as determined by the Birchwood Insight Scale (BIS) symptom relabeling subscale score and cortical thickness of frontal regions of interest (ROIs). We then examined for an association between symptom attribution and cortical thickness using multiple regression analysis.

RESULTS

FES patients exhibited significantly reduced cortical thicknesses for a number of frontal regions, namely the left medial orbitofrontal, left superior frontal, left frontal pole, right rostral middle frontal, right lateral orbitofrontal and right superior frontal regions. Reduced cortical thickness in FES patients was associated with symptom misattribution for the left and right rostral middle frontal, left caudal anterior cingulate, right superior frontal, and left and right pars triangularis regions. Reduced left rostral middle frontal thickness and left anterior cingulate thickness remained significant on regression analysis.

CONCLUSION

Our findings suggest that frontal neuroanatomical deficits that are present early in the disease process may be critical to the pathogenesis of symptom attribution in schizophrenia.

Association of neurocognitive deficits and insight in schizophrenia

AIM

To evaluate the relationship between neurocognitive deficits and insight (clinical & cognitive) among patients with schizophrenia in clinical remission.

METHODOLOGY

60 patients with schizophrenia (diagnosed as per the DSM-IV criteria) in clinical remission were assessed on Beck Cognitive Insight scale (BCIS), Positive and Negative symptom scale (PANSS) and neurocognitive battery (Trail A and B, Stroop Test, Controlled Oral Words Association (COWA) and Tower of London (TOL).

RESULTS

Lower processing speed, low cognitive flexibility and poor executive functions as assessed by Trail A, Trail B and TOL respectively and higher verbal fluency (COWA) were associated with poor cognitive insight in the self-certainty domain. Poor executive functioning (3 moves problem of TOL) was associated with lower cognitive insight in the domain of self-reflectiveness. Clinical insight as assessed by item number 12 of general psychopathology subscale of PANSS did not have any association with any of the neurocognitive domains except for few subsets of executive functions as assessed by TOL. There was no correlation between clinical insight and cognitive insight. However, many of these correlations were weak and could be due to Type-1 error as significance of correlation was fixed at two tailed 0.05 level. Multiple regression analysis demonstrated cognitive flexibility as assessed by Trail B test and executive functions (3 moves and 5 moves problems of TOL) to be the significant predictors of self-certainty and self- reflectiveness domains of the cognitive insight.

CONCLUSIONS

The present study suggests that poor cognitive flexibility and executive dysfunction are associated with poor cognitive insight but the impact of poor neurocognitions on the clinical insight is not very significant.

Altered grey matter volume and cortical thickness in patients with schizo-obsessive comorbidity

Recent findings suggest that schizo-obsessive comorbidity (SOC) may be a unique diagnostic entity. We examined grey matter (GM) volume and cortical thickness in 22 patients with SOC, and compared them with 21 schizophrenia (SCZ) patients, 22 obsessive-compulsive disorder (OCD) patients and 22 healthy controls (HCs). We found that patients with SOC exhibited reduced GM volume in the left thalamus, the left inferior semi-lunar lobule of the cerebellum, the bilateral medial orbitofrontal cortex (medial oFC), the medial superior frontal gyrus (medial sFG), the rectus gyrus and the anterior cingulate cortex (aCC) compared with HCs. Patients with SOC also exhibited reduced cortical thickness in the right superior temporal gyrus (sTG), the right angular gyrus, the right supplementary motor area (SMA), the right middle cingulate cortex (mCC) and the right middle occipital gyrus (mOG) compared with HCs. Together with the differences in GM volume and cortical thickness between patients with SOC and patients with only SCZ or only OCD, these findings highlight the GM changes specific to patients with SOC.

The right occipital lobe and poor insight in first-episode psychosis

Lack of insight is a core feature of non-affective psychosis and has been associated with poorer outcomes. Brain abnormalities underlying lack of insight have been suggested, mostly in the frontal lobe, although previous research showed mixed results. We used a voxel-based morphometry (VBM) analysis in 108 first-episode non-affective psychosis patients to investigate the pattern of brain structural abnormalities related to lack of insight. In addition, 77 healthy volunteers were compared with the patients classified as having poor and good insight. The shortened version of the Scale to Assess Unawareness of Mental Disorder was used to evaluate insight. Patients with poor insight (n = 68) compared with patients with good insight (n = 40) showed a single significant cluster (kc = 5834; PcFWE = 0.001) of reduced grey matter volume (GMV) in the right occipital lobe extending to its lateral and medial surfaces, the cuneus, and the middle temporal gyrus. In addition, GMV at this cluster showed a negative correlation with the score of the SUMD (r = -0.305; p = 0.001). When comparing patients with poor insight with healthy subjects overall reductions of GMV were found, mainly in frontal and occipital lobes. Hence, poor insight in non-affective psychosis seems to be associated with specific brain abnormalities in the right occipital and temporal cortical regions. Dysfunction in any combination of these areas may contribute to lack of insight in non-affective psychosis. Specifically, the 'right' hemisphere dysfunction underlying impaired insight in our sample is consistent with previously reported similarities between lack of insight in psychosis and anosognosia in neurological disorders.

Stronger default mode network connectivity is associated with poorer clinical insight in youth at ultra high-risk for psychotic disorders

Impaired clinical insight (CI) is a common symptom of psychotic disorders and a promising treatment target. However, to date, our understanding of how variability in CI is tied to underlying brain dysfunction in the clinical high-risk period is limited. Developing a stronger conception of this link will be a vital first step for efforts to determine if CI can serve as a useful prognostic indicator. The current study investigated whether variability in CI is related to major brain networks in adolescents and young adults at ultra high-risk (UHR) of developing psychosis. Thirty-five UHR youth were administered structured clinical interviews as well as an assessment for CI and underwent resting-state magnetic resonance imaging scans. Functional connectivity was calculated in the default mode network (DMN) and fronto-parietal network (FPN), two major networks that are dysfunctional in psychosis and are hypothesized to affect insight. Greater DMN connectivity between the posterior cingulate/precuneus and ventromedial prefrontal cortex (DMN) was related to poorer CI (R²=0.399). There were no significant relationships between insight and the FPN. This is the first study to relate a major brain network to clinical insight before the onset of psychosis. Findings are consistent with evidence if a hyperconnected DMN in schizophrenia and UHR, and similar to a previous study of insight and connectivity in schizophrenia. Results suggest that a strongly connected DMN may be related to poor self-awareness of subthreshold psychotic symptoms in UHR adolescents and young adults.

Vestibular stimulation improves insight into illness in schizophrenia spectrum disorders

Impaired insight into illness (IMP-INS) is common among individuals with schizophrenia spectrum disorders (SSD), contributing to medication nonadherence and poor clinical outcomes. Caloric vestibular simulation (CVS) is typically used to assess peripheral vestibular system function. Left cold CVS is also a transiently effective treatment for IMP-INS and hemineglect secondary to right brain hemisphere stroke, and possibly for IMP-INS and mood stabilization in patients with SSD. Participants with SSD and moderate-to-severe IMP-INS participated in an exploratory double blind, crossover, randomized controlled study of the effects of CVS on IMP-INS. Participants sequentially received all experimental conditions-left cold (4°C), right cold, and body temperature/sham CVS-in a random order. Repeated measures ANOVA were performed to compare changes in IMP-INS, mood and positive symptom severity pre and 30min post CVS. A significant interaction was found between CVS condition, time, and body temperature nystagmus peak slow phase velocity (PSPV) for IMP-INS, indicating that single session left cold CVS transiently improved IMP-INS while right cold CVS may have worsened IMP-INS, particularly in participants with greater vestibular reactivity (i.e. higher PSPV) to body temperature CVS. The procedure's effectiveness is attributed to stimulation of underactive right hemisphere circuits via vestibular nuclei projections to the contralateral hemisphere.

Insight and white matter fractional anisotropy in first-episode schizophrenia

Impaired insight is a hallmark feature of schizophrenia. Structural studies implicate predominantly prefrontal, cingulate, cuneus/precuneus, and inferior temporal brain regions. The cortical midline structures (CMS) are also implicated in functional studies primarily through self-reflective processing tasks. However, few studies have explored the relationship between white matter tracts and insight in schizophrenia, and none in first-episode schizophrenia (FES). Here, we examined for fractional anisotropy (FA) differences in 89 minimally treated FES patients and 98 matched controls, and identified those FA differences associated with impaired clinical insight in patients. We found widespread FA reduction in FES patients compared to controls. Poorer insight in patients was predicted by lower FA values in a number of white matter tracts with a predilection for tracts associated with cortical midline structures (fronto-occipital, cingulate, cingulate hippocampus, uncinate, anterior corona radiata), and more severe depressive symptoms. The association between FA abnormalities and insight was most robust for the awareness of symptoms and illness awareness domains. Our study implicates a network of tracts involved in impaired insight in schizophrenia with a predilection for the CMS. This study is a first step in delineating the white matter tracts involved in insight impairment in schizophrenia prior to chronicity.

The metabolic basis of cognitive insight in psychosis: A positron emission tomography study

The purpose of this study was to investigate the relationship between cognitive insight and cerebral metabolism in patients suffering from psychosis. The Beck Cognitive Insight Scale (BCIS) was administered to 63 patients with psychosis undergoing Positron Emission Tomography investigation. The sample was divided into two groups considering the BCIS score. Data were analyzed using Statistical Parametric Mapping.

RESULTS

patients with low insight, compared to those with high insight, showed decreased metabolism in the right fusiform gyrus, left precuneus, superior temporal gyrus and insula bilaterally, as well as increased metabolism in the left orbito-frontal gyrus (all p<0.005). Our results suggest that reduced posterior (occipito-temporo-insulo-parietal) and increased anterior (orbitofrontal) cerebral metabolism may sustain low cognitive insight in psychosis.

Longitudinal trajectory of clinical insight and covariation with cortical thickness in first-episode psychosis

Among people with a first-episode of psychosis, those with poorer clinical insight show neuroanatomical abnormalities in frontal, temporal and parietal cortices compared to those with better clinical insight. Whether changes in clinical insight are associated with progressive structural brain changes is unknown. We aimed to evaluate 1) associations between clinical insight and cortical thickness at a baseline assessment, 2) covariation between clinical insight and cortical thickness across baseline, one-year and two-year follow-up assessments, and 3) the predictive value of clinical insight for cortical thickness at one-year and two-year follow-ups. Scale for the assessment of Unawareness of Mental Disorder ratings and magnetic resonance imaging scans were acquired at baseline, one-year, and two-year follow-ups in 128, 74, and 44 individuals with a first-episode psychosis, respectively. Cortical thickness metrics were then computed at baseline, one-year and two-year follow-ups and analyzed with linear mixed models. At baseline, clinical insight was not significantly associated with cortical thickness in any region. Longitudinal mixed effects models showed that a worsening in clinical insight between the one-year and two-year assessments was significantly associated with cortical thinning in dorsal pre-central and post-central gyri. Cortical thinning in left fusiform gyrus at two-years was predicted by poorer clinical insight at baseline. Results suggest that poor clinical insight soon after the onset of a first-episode psychosis may lead to progressive cortical changes in temporal lobe, while changes in clinical insight during the second year covary with cortical thinning in circumscribed dorsal frontal and parietal cortices.

How self-reflection and self-certainty are related to neurocognitive functioning: an examination of cognitive insight in bipolar disorder

INTRODUCTION

The pattern of associations between clinical insight, cognitive insight, and neurocognitive functioning was assessed in bipolar disorder patients.

METHODS

Data from 42 bipolar disorder patients were examined. Cognitive insight was measured using the Beck Cognitive Insight Scale (BCIS). The BCIS is a 15-item self-report instrument consisting of two subscales, self-reflectiveness and self-certainty. Clinical insight was measured by the use of the item G12 of the Positive and Negative Syndrome Scale. Neurocognitive functioning was assessed using the International Society for Bipolar Disorders-Battery for Assessment of Neurocognition.

RESULTS

Correlation analyses revealed significant positive associations between self-reflectiveness and speed of processing, attention, working memory, visual learning, and reasoning and problem solving. The subscale self-certainty was negatively correlated to working memory, however, this correlation disappeared when we controlled for confounding variables. No correlations between clinical insight and neurocognition were found. In addition, there was no association between cognitive insight and clinical insight.

CONCLUSION

Better neurocognitive functioning was more related to higher levels of self-reflectiveness than to diminished self-certainty.

Voxel-based magnetic resonance imaging investigation of poor and preserved clinical insight in people with schizophrenia

AIM

To define regional grey-matter abnormalities in schizophrenia patients with poor insight (Insight^-), relative to patients with preserved clinical insight (Insight⁺), and healthy controls.

METHODS

Forty stable schizophrenia outpatients (20 Insight^- and 20 Insight⁺) and 20 healthy controls underwent whole brain magnetic resonance imaging (MRI). Insight in all patients was assessed using the Birchwood Insight Scale (BIS; a self-report measure). The two patient groups were pre-selected to match on most clinical and demographic parameters but, by design, they had markedly distinct BIS scores. Voxel-based morphometry employed in SPM8 was used to examine group differences in grey matter volumes across the whole brain.

RESULTS

The three participant groups were comparable in age [F(2,57) = 0.34, P = 0.71] and the patient groups did not differ in age at illness onset [t(38) = 0.87, P = 0.39]. Insight^- and Insight⁺ patient groups also did not differ in symptoms on the Positive and Negative Syndromes scale (PANSS): Positive symptoms [t(38) = 0.58, P = 0.57], negative symptoms [t(38) = 0.61, P = 0.55], general psychopathology [t(38) = 1.30, P = 0.20] and total PANSS scores [t(38) = 0.21, P = 0.84]. The two patient groups, as expected, varied significantly in the level of BIS-assessed insight [t(38) = 12.11, P < 0.001]. MRI results revealed lower fronto-temporal, parahippocampal, occipital and cerebellar grey matter volumes in Insight^- patients, relative to Insight⁺ patients and healthy controls (for all clusters, family-wise error corrected P < 0.05). Insight⁺ patient and healthy controls did not differ significantly (P > 0.20) from each other.

CONCLUSION

Our findings demonstrate a clear association between poor clinical insight and smaller fronto-temporal, occipital and cerebellar grey matter volumes in stable long-term schizophrenia patients.

Self-reflection and set-shifting mediate awareness in cognitively preserved schizophrenia patients

BACKGROUND

Poor insight in schizophrenia has been linked to poor cognitive functioning, psychological processes such as denial, or more recently with impaired metacognitive capacity. Few studies, however, have investigated the potential co-dependency of multiple factors in determining level of insight, but such a model is necessary in order to account for patients with good cognitive functioning who have very poor awareness. As evidence suggests that set-shifting and cognitive insight (self-reflection (SR) and self-certainty) are strong predictors of awareness we proposed that these factors are key mediators in the relationship between cognition and awareness. We hypothesised that deficits specifically in SR and set-shifting determine level of awareness in the context of good cognition.

METHODS

Thirty schizophrenia patients were stratified by high and low awareness of illness and executive functioning scores. Cognitive insight, cognition, mood and symptom measures were compared between sub-groups.

RESULTS

A low insight/high executive functioning (LI-HE) group, a high insight/high executive functioning (HI-HE) group and a low insight/low executive functioning (LI-LE) group were revealed. As anticipated, the LI-HE patients showed significantly lower capacity for SR and set-shifting than the HI-HE patients.

CONCLUSIONS

This study indicates that good cognitive functioning is necessary but not sufficient for good awareness; good awareness specifically demands preserved capacity to self-reflect and shift-set. Results support Nelson and Narens' [1990. Metamemory: A theoretical framework and new findings. The Psychology of Learning and Motivation, 26, 125-173] model of metacognition by which awareness is founded on control (set-shifting) and monitoring (SR) processes. These specific factors could be targeted to improve insight in patients with otherwise unimpaired cognitive function.

Insight in Psychiatry and Neurology: State of the Art, and Hypotheses

In spite of the increasing number of studies on insight in psychiatry and also in neurology and psychology, its nature is still elusive. It encompasses at least three fundamental characteristics: the awareness of suffering from an illness, an understanding of the cause and source of this suffering, and an acknowledgment of the need for treatment. As such, insight is fundamental for patients' management, prognosis, and treatment. Not surprisingly, the majority of available data, which have been gathered on schizophrenia, show a relationship between low insight and poorer outcomes. For mood disorders, however, insight is associated with less positive results. For other psychiatric disorders, insight has rarely been investigated. In neurology, the impaired ability to recognize the presence of sensory, perceptual, motor, affective, or cognitive functioning-referred to as anosognosia-has been related to damage of specific brain regions. This article provides a comprehensive review of insight in different psychiatric and neurological disorders, with a special focus on brain areas and neurotransmitters that serve as the substrate for this complex phenomenon.

Cortical thickness and low insight into symptoms in enduring schizophrenia

Poor insight is a common, multidimensional phenomenon in patients with schizophrenia, associated with poorer outcomes and treatment non-adherence. Yet scant research has investigated the neuronal correlates of insight into symptoms (IS), a dimension of insight that may be particularly significant in enduring schizophrenia. Sixty-six patients with enduring schizophrenia (duration >4years) and 33 healthy controls completed MRI scanning and IQ, depression, and anxiety assessments. The Scale to Assess Insight-Expanded (SAI-E) measured insight into patients' four most prominent symptoms and patients were classified into two groups: low IS (0-2; n=33), and high IS (>2; n=33). We evaluated the association between cortical thickness (CT) and insight into symptoms using two methods: (1) a between-patients region-of-interest analysis in the insula, superior temporal gyrus (STG) and frontal lobe; and (2) a whole-brain exploratory regression between patient and controls. Brain regions were segmented using a neuroanatomical atlas and vertex-wise CT analyses were conducted with CIVET, covaried for age and sex. ROI analysis revealed thinner insula cortex in patients with low IS (p<0.05, surviving FDR correction). Patients with low IS also showed significantly thinner right insula, STG, and parahippocampal cortex compared to healthy controls (p<0.05, surviving FDR correction). Regions of observed CT reductions have been hypothesized to subserve self-monitoring, error awareness, and ability to identify hallucinations. Results highlight an important association between right insula abnormalities and impaired IS in schizophrenia. The diverse clinical presentation of patients further suggests an independent relationship between symptomology and insight-related differences in CT that has been previously unexplored in enduring schizophrenia.

Neurosurgery for schizophrenia: an update on pathophysiology and a novel therapeutic target

The main objectives of this review were to provide an update on the progress made in understanding specific circuit abnormalities leading to psychotic symptoms in schizophrenia and to propose rational targets for therapeutic deep brain stimulation (DBS). Refractory schizophrenia remains a major unsolved clinical problem, with 10%-30% of patients not responding to standard treatment options. Progress made over the last decade was analyzed through reviewing structural and functional neuroimaging studies in humans, along with studies of animal models of schizophrenia. The authors reviewed theories implicating dysfunction in dopaminergic and glutamatergic signaling in the pathophysiology of the disorder, paying particular attention to neurosurgically relevant nodes in the circuit. In this context, the authors focused on an important pathological circuit involving the associative striatum, anterior hippocampus, and ventral striatum, and discuss the possibility of targeting these nodes for therapeutic neuromodulation with DBS. Finally, the authors examined ethical considerations in the treatment of these vulnerable patients. The functional anatomy of neural circuits relevant to schizophrenia remains of great interest to neurosurgeons and psychiatrists and lends itself to the development of specific targets for neuromodulation. Ongoing progress in the understanding of these structures will be critical to the development of potential neurosurgical treatments of schizophrenia.

Neuroanatomical correlates of awareness of illness in patients with amnestic mild cognitive impairment who will or will not convert to Alzheimer's disease

BACKGROUND

Awareness of cognitive deficits may be reduced in mild cognitive impairment (MCI). This may have a detrimental effect on illness course and may be a predictor of subsequent conversion to AD. Although neuropsychological correlates have been widely investigated, no evidence of a neuroanatomical basis of the phenomenon has been reported yet. This study was aimed at investigating the neuroanatomical correlates of deficit awareness in amnestic MCI to determine whether they constitute risk factors for conversion to AD.

METHOD

A sample of 36 first-diagnosis amnestic MCI patients were followed for five years. At the first diagnostic visit they were administered an extensive diagnostic and clinical procedure and the Memory Insight Questionnaire (MIQ), measuring a total index and four sub-indices, to investigate awareness of deficits in dementia; they also underwent a high resolution T1-weighted Magnetic Resonance Imaging (MRI) investigation. Grey matter brain volumes were analysed on a voxel-by-voxel basis using Statistical Parametric Mapping 8. Data of 10 converter patients (CONV) and those of 26 non converter patients (NOCONV) were analysed using multiple regression models.

RESULTS

At baseline, self-awareness of memory deficits was poorer in CONV compared to NOCONV. Furthermore, reduced awareness of cognitive deficits in CONV correlated with reduced grey matter volume of the anterior cingulate (memory deficit awareness), right pars triangularis of the inferior frontal cortex (memory deficit awareness) and cerebellar vermis (total awareness), whereas in NOCONV it correlated with reduced grey matter volume of left superior (total awareness) and middle (language deficit awareness) temporal areas. Further, at baseline self-awareness of memory deficits were poorer in CONV than in NOCONV.

CONCLUSIONS

Defective awareness of cognitive deficits is underpinned by different mechanisms in CONV and NOCONV amnestic MCI patients. Our data support the hypothesis that poor awareness of cognitive deficit is a predictor of subsequent conversion to AD.

Neurobiology of insight deficits in schizophrenia: An fMRI study

Prior research has shown insight deficits in schizophrenia to be associated with specific neuroimaging changes (primarily structural) especially in the prefrontal sub-regions. However, little is known about the functional correlates of impaired insight. Seventeen patients with schizophrenia (mean age 40.0±10.3; M/F=14/3) underwent fMRI on a Philips 3.0 T Achieva system while performing on a self-awareness task containing self- vs. other-directed sentence stimuli. SPM5 was used to process the imaging data. Preprocessing consisted of realignment, coregistration, and normalization, and smoothing. A regression analysis was used to examine the relationship between brain activation in response to self-directed versus other-directed sentence stimuli and average scores on behavioral measures of awareness of symptoms and attribution of symptoms to the illness from Scale to Assess Unawareness of Mental Disorders. Family Wise Error correction was employed in the fMRI analysis. Average scores on awareness of symptoms (1=aware; 5=unaware) were associated with activation of multiple brain regions, including prefrontal, parietal and limbic areas as well as basal ganglia. However, average scores on correct attribution of symptoms (1=attribute; 5=misattribute) were associated with relatively more localized activation of prefrontal cortex and basal ganglia. These findings suggest that unawareness and misattribution of symptoms may have different neurobiological basis in schizophrenia. While symptom unawareness may be a function of a more complex brain network, symptom misattribution may be mediated by specific brain regions.

Connecting clinical and experimental investigations of awareness in traumatic brain injury

Questionnaire-based demonstrations of impaired self-awareness (SA) after traumatic brain injury (TBI) are not always supported by experimental studies of in-the-moment or online awareness. This chapter begins by describing the clinical phenomenon of impaired SA, how it is measured, and why its interdependency with mechanisms of online awareness may provide the scaffolding from which appraisals of cognitive functioning can be accurately revised following a brain injury. We review research that has measured unawareness of errors in routine action in TBI patients and propose more rigorous methodological approaches to studying the emergent properties of awareness with greater clarity in the laboratory. We discuss how neuropsychological and electrophysiologic studies are beginning to inform our understanding of impaired error processing in TBI patients and we highlight recent theory proposing that online metacognitive processes accumulate evidence of erroneous responses in a graded fashion. Neural signals with amplitudes that scale with the strength of accruing evidence and peak latencies that mark the threshold at which awareness emerges represent important neural mechanisms to examine the breakdown of error awareness after brain injury. We also discuss how errors can be investigated in relation to different sources of evidence that contribute to aware experiences after brain injury. Finally, we explore conditions beyond error signaling, and how different "objects of insight" that require retrospective and prospective judgments of confidence need to be examined in relation to the clinical phenomenon of impaired SA.

Impaired insight into illness and cognitive insight in schizophrenia spectrum disorders: resting state functional connectivity

BACKGROUND

Impaired insight into illness (clinical insight) in schizophrenia has negative effects on treatment adherence and clinical outcomes. Schizophrenia is described as a disorder of disrupted brain connectivity. In line with this concept, resting state networks (RSNs) appear differentially affected in persons with schizophrenia. Therefore, impaired clinical, or the related construct of cognitive insight (which posits that impaired clinical insight is a function of metacognitive deficits), may reflect alterations in RSN functional connectivity (fc). Based on our previous research, which showed that impaired insight into illness was associated with increased left hemisphere volume relative to right, we hypothesized that impaired clinical insight would be associated with increased connectivity in the DMN with specific left hemisphere brain regions.

METHODS

Resting state MRI scans were acquired for participants with schizophrenia or schizoaffective disorder (n=20). Seed-to-voxel and ROI-to-ROI fc analyses were performed using the CONN-fMRI fc toolbox v13 for established RSNs. Clinical and cognitive insight were measured with the Schedule for the Assessment of Insight-Expanded Version and Beck Cognitive Insight Scale, respectively, and included as the regressors in fc analyses.

RESULTS

As hypothesized, impaired clinical insight was associated with increased connectivity in the default mode network (DMN) with the left angular gyrus, and also in the self-referential network (SRN) with the left insula. Cognitive insight was associated with increased connectivity in the dorsal attention network (DAN) with the right inferior frontal cortex (IFC) and left anterior cingulate cortex (ACC).

CONCLUSION

Increased connectivity in DMN and SRN with the left angular gyrus and insula, respectively, may represent neural correlates of impaired clinical insight in schizophrenia spectrum disorders, and is consistent with the literature attributing impaired insight to left hemisphere dominance. Increased connectivity in the DAN with the IFC and ACC in relation to cognitive insight may facilitate enhanced mental flexibility in this sample.

The effects of aging on insight into illness in schizophrenia: a review

OBJECTIVES

Impaired insight into illness is a prevalent feature of schizophrenia, which negatively influences treatment adherence and clinical outcomes. Little is known about the effects of aging on insight impairment. We aimed to review the available research literature on the effects of aging on insight into illness in schizophrenia, in relation to positive, negative, and cognitive symptoms. Ultimately, we propose a trajectory of insight in schizophrenia across the lifespan.

METHOD

A systematic Medline® literature search was conducted, searching for English language studies describing the relationship of insight into illness in schizophrenia with aging.

RESULTS

We identified 62 studies. Insight impairment is associated with illness severity, premorbid intellectual function (i.e. IQ), executive function, and memory. Insight impairment improves modestly during midlife, worsening again in late life. It tends to fluctuate with each episode of psychosis, likely in relation to worsening positive symptoms that improve with antipsychotic treatment. The relationship between insight impairment and cognitive dysfunction appears to attenuate with age, while the relationship with lower premorbid intellectual function is preserved. The association between impaired insight and negative symptoms is unclear.

CONCLUSIONS

The available literature suggests that the course of insight impairment follows a U-shaped curve, where insight impairment is severe during the first episode of psychosis, modestly improves over midlife, and declines again in late life. Future studies are required to investigate the trajectory of insight into illness and its core domains across the lifespan from prodromal phase to late life.

Illness denial in schizophrenia spectrum disorders: a function of left hemisphere dominance

Impaired illness awareness or anosognosia is a common, but poorly understood feature of schizophrenia that contributes to medication nonadherence and poor treatment outcomes. Here we present a functional imaging study to measure brain activity at the moment of illness denial. To accomplish this, participants with schizophrenia (n = 18) with varying degrees of illness awareness were confronted with their illness beliefs while undergoing functional MRI. To link structure with function, we explored the relationships among impaired illness awareness and brain activity during the illness denial task with cortical thickness. Impaired illness awareness was associated with increased brain activity in the left temporoparieto-occipital junction (TPO) and left medial prefrontal cortex (mPFC) at the moment of illness denial. Brain activity in the left mPFC appeared to be a function of participants' degree of self-reflectiveness, while the activity in the left TPO was associated with cortical thinning in this region and more specific to illness denial. Participants with impaired illness awareness had slower response times to illness related stimuli than those with good illness awareness. Increased left hemisphere brain activity in association with illness denial is consistent with the literature in other neuropsychiatric conditions attributing anosognosia or impaired illness awareness to left hemisphere dominance. The TPO and mPFC may represent putative targets for noninvasive treatment interventions, such as transcranial magnetic or direct current stimulation.

Neural correlates of insight in dreaming and psychosis

The idea that dreaming can serve as a model for psychosis has a long and honourable tradition, however it is notoriously speculative. Here we demonstrate that recent research on the phenomenon of lucid dreaming sheds new light on the debate. Lucid dreaming is a rare state of sleep in which the dreamer gains insight into his state of mind during dreaming. Recent electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI) data for the first time allow very specific hypotheses about the dream-psychosis relationship: if dreaming is a reasonable model for psychosis, then insight into the dreaming state and insight into the psychotic state should share similar neural correlates. This indeed seems to be the case: cortical areas activated during lucid dreaming show striking overlap with brain regions that are impaired in psychotic patients who lack insight into their pathological state. This parallel allows for new therapeutic approaches and ways to test antipsychotic medication.

Self-awareness in neurodegenerative disease relies on neural structures mediating reward-driven attention

Accurate self-awareness is essential for adapting one's tasks and goals to one's actual abilities. Patients with neurodegenerative diseases, particularly those with right frontal involvement, often present with poor self-awareness of their functional limitations that may exacerbate their already jeopardized decision-making and behaviour. We studied the structural neuroanatomical basis for impaired self-awareness among patients with neurodegenerative disease and healthy older adults. One hundred and twenty-four participants (78 patients with neurodegenerative diseases including Alzheimer's disease, behavioural variant frontotemporal dementia, right-temporal frontotemporal dementia, semantic variant and non-fluent variant primary progressive aphasia, and 46 healthy controls) described themselves on the Patient Competency Rating Scale, rating observable functioning across four domains (daily living activities, cognitive, emotional control, interpersonal). All participants underwent structural magnetic resonance imaging. Informants also described subjects' functioning on the same scale. Self-awareness was measured by comparing self and informant ratings. Group differences in discrepancy scores were analysed using general linear models, controlling for age, sex and disease severity. Compared with controls, patients with behavioural variant frontotemporal dementia overestimated their functioning in all domains, patients with Alzheimer's disease overestimated cognitive and emotional functioning, patients with right-temporal frontotemporal dementia overestimated interpersonal functioning, and patients with non-fluent aphasia overestimated emotional and interpersonal functioning. Patients with semantic variant aphasia did not overestimate functioning on any domain. To examine the neuroanatomic correlates of impaired self-awareness, discrepancy scores were correlated with brain volume using voxel-based morphometry. To identify the unique neural correlates of overlooking versus exaggerating deficits, overestimation and underestimation scores were analysed separately, controlling for age, sex, total intracranial volume and extent of actual functional decline. Atrophy related to overestimating one's functioning included bilateral, right greater than left frontal and subcortical regions, including dorsal superior and middle frontal gyri, lateral and medial orbitofrontal gyri, right anterior insula, putamen, thalamus, and caudate, and midbrain and pons. Thus, our patients' tendency to under-represent their functional decline was related to degeneration of domain-general dorsal frontal regions involved in attention, as well as orbitofrontal and subcortical regions likely involved in assigning a reward value to self-related processing and maintaining accurate self-knowledge. The anatomic correlates of underestimation (right rostral anterior cingulate cortex, uncorrected significance level) were distinct from overestimation and had a substantially smaller effect size. This suggests that underestimation or 'tarnishing' may be influenced by non-structural neurobiological and sociocultural factors, and should not be considered to be on a continuum with overestimation or 'polishing' of functional capacity, which appears to be more directly mediated by neural circuit dysfunction.

Insight in mental illness: an educational review

Insight is an elusive concept in psychiatry with a long history of divergent definitions and methods of measurements. Although insight was previously presumed to be a binary construct that an individual could possess or lack, there is an emerging consensus that insight is a multi-dimensional construct consisting of a spectrum of phenomena. Over recent years there has been increasing interest in the topic of insight, especially in relation to psychotic disorders where insight is frequently diminished. In this educational review we will discuss the history associated with the construct of insight, current theories in relation to insight, the association of insight with clinical symptoms and prognosis with particular reference to psychosis, the various methods of measuring insight, the aetiology of insight and present deficiencies in our understanding of insight.

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.

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.

Frontotemporoparietal asymmetry and lack of illness awareness in schizophrenia

INTRODUCTION

Lack of illness awareness or anosognosia occurs in both schizophrenia and right hemisphere lesions due to stroke, dementia, and traumatic brain injury. In the latter conditions, anosognosia is thought to arise from unilateral hemispheric dysfunction or interhemispheric disequilibrium, which provides an anatomical model for exploring illness unawareness in other neuropsychiatric disorders, such as schizophrenia.

METHODS

Both voxel-based morphometry using Diffeomorphic Anatomical Registration through Exponentiated Lie Algebra (DARTEL) and a deformation-based morphology analysis of hemispheric asymmetry were performed on 52 treated schizophrenia subjects, exploring the relationship between illness awareness and gray matter volume. Analyses included age, gender, and total intracranial volume as covariates.

RESULTS

Hemispheric asymmetry analyses revealed illness unawareness was significantly associated with right < left hemisphere volumes in the anteroinferior temporal lobe (t = 4.83, P = 0.051) using DARTEL, and the dorsolateral prefrontal cortex (t = 5.80, P = 0.003) and parietal lobe (t = 4.3, P = 0.050) using the deformation-based approach. Trend level associations were identified in the right medial prefrontal cortex (t = 4.49, P = 0.127) using DARTEL. Lack of illness awareness was also strongly associated with reduced total white matter volume (r = 0.401, P < 0.01) and illness severity (r = 0.559, P < 0.01).

CONCLUSION

These results suggest a relationship between anosognosia and hemispheric asymmetry in schizophrenia, supporting previous volume-based MRI studies in schizophrenia that found a relationship between illness unawareness and reduced right hemisphere gray matter volume. Functional imaging studies are required to examine the neural mechanisms contributing to these structural observations.

Association of grey matter volume deviation with insight impairment in first-episode affective and non-affective psychosis

The neurobiological correlates of impaired insight in psychotic illness remain uncertain and may be confounded by factors such as illness progression and medication use. Our study consisted of two separate experiments. In the first experiment, we examined the association between measures of insight and regional brain volume in thirty-two patients with first-episode psychosis. In the second experiment, we looked at similar associations in thirty individuals with chronic schizophrenia. Detailed measures of symptom awareness and symptom attribution were obtained using the Scale to assess Unawareness of Mental Disorder. MRI scans were acquired and analysed using Statistical Non-Parametric Mapping for voxel-based analyses of grey matter maps. Regression models were used to assess the relationship between insight and grey matter volume in both the first-episode psychosis and the chronic schizophrenia experiments whilst controlling for potential confounds. In first-episode psychosis patients, symptom misattribution was associated with increased grey matter in the right and left caudate, right thalamus, left insula, putamen and cerebellum. In the chronic schizophrenia study, there were no significant associations between regional grey matter volume and measures of insight. These findings suggest that neuroplastic changes within subcortical and frontotemporal regions are associated with impaired insight in individuals during their first episode of psychosis.

Judgements of agency in schizophrenia: an impairment in autonoetic metacognition

We investigated judgements of agency in participants with schizophrenia and healthy controls. Participants engaged in a computer game in which they attempted to touch downward falling Xs and avoid touching Os. On some trials, participants were objectively in perfect control. On other trials, they were objectively not in complete control because the movement of the cursor on the screen was distorted with respect to the position of the mouse by random noise (turbulence), or it was lagged by 250 or 500 ms. Participants made metacognitive judgements of agency as well as judgements of performance. Control participants' judgements of agency were affected by the turbulence and lag variables-indicating that they knew they were objectively not in control in those conditions, and they were also influenced by their assessments of performance. The patients also used their assessments of performance but neither turbulence nor lag affected their judgements of agency. This indicated an impairment in agency monitoring. The patients, unlike the healthy controls, used only publically available external cues about performance in making judgements of 'agency' and did not rely on any additional access to internal self-relevant cues that were diagnostic in indicating whether or not they were, in fact, in control.

Failures of metacognition and lack of insight in neuropsychiatric disorders

Lack of insight or unawareness of illness are the hallmarks of many psychiatric disorders, especially schizophrenia (SCZ) and other psychoses and could be conceived of as a failure in metacognition. Research in this area in the mental health field h as burgeoned with the development and widespread use of standard assessment instruments and the mapping out of the clinical and neuropsychological correlates of insight and its loss. There has been a growing appreciation of the multi-faceted nature of the concept and of the different 'objects' of insight, such as the general awareness that one is ill, to more specific metacognitive awareness of individual symptoms, impairments and performance. This in turn has led to the notion that insight may show modularity and may fractionate across different domains and disorders, supported by work that directly compares metacognition of memory deficits and illness awareness in patients with SCZ, Alzheimer's disease and brain injury. The focus of this paper will be on the varieties of metacognitive failure in psychiatry, particularly the psychoses. We explore cognitive models based on self-reflectiveness and their possible social and neurological bases, including data from structural and functional MRI. The medial frontal cortex appears to play an important role in self-appraisal in health and disease.

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.

Self-evaluation in schizophrenia: an fMRI study with implications for the understanding of insight

BACKGROUND

Lack of insight is a core feature of schizophrenia and is associated with structural brain abnormalities. The functional neuroanatomy of insight has only recently been investigated. When people evaluate their personality traits compared to those of another, activation is seen in central midline structures (CMS) of the brain. This study set out to compare cerebral activation in schizophrenia patients versus controls during a self-evaluation task which included positive and negative traits as well as mental and physical illness terms.

METHODS

Eleven schizophrenia patients and 8 healthy controls, matched for age were studied. Insight was assessed using the Schedule for the Assessment of Insight-expanded version (SAI-E). FMRI data were obtained with a 1.5 Tesla GE system and interactions between participant group, self versus other, significant at the cluster level, were recorded.

RESULTS

Significant hypoactivation in the medial superior frontal gyrus (dorsomedial prefrontal cortex) was observed in patients vs. controls during self-evaluation of all traits combined. A second cluster of hypoactivation in the posterior cingulate was also detected. When the response to individual traits was explored, underactivation in other frontal regions plus right inferior parietal lobule emerged and this tended to correlate, albeit weakly with lower insight scores. Further, there were areas of hyperactivation relative to controls in anterior cingulate, frontal and parietal regions (especially precuneus) which showed moderate inverse correlations with insight scores.

CONCLUSIONS

We have demonstrated that the CMS, identified as a key system underpinning self-evaluation, is dysfunctional in patients with schizophrenia, particularly dorso-medial PFC. This may have implications for lack of insight in schizophrenia. Hypofunction within the dorsomedial prefrontal region seems to be particularly important although other posterior and lateral cortical regions play a part and may modulate self-evaluative responses depending on the type of trait under consideration.

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.

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.

Theory of mind skills are related to gray matter volume in the ventromedial prefrontal cortex in schizophrenia

BACKGROUND

Among individuals with schizophrenia, deficits in theory of mind (ToM) skills predict poor social functioning. Therefore, identifying the neural basis of ToM may assist the development of treatments that improve social outcomes. Despite growing evidence that the ventromedial prefrontal cortex (VMPFC) facilitates ToM skills among healthy individuals, methodological challenges, such as the influence of general cognitive deficits, have made it difficult to identify the relationship between ToM processing and VMPFC function in schizophrenia.

METHODS

We used voxel-based morphometry and a multi-method behavioral assessment of ToM processing, including performance-based (Recognition of Faux Pas Test), self-report (Interpersonal Reactivity Index, Perspective-Taking), and interview-rated (Quality of Life Scale-Empathy score) ToM assessments, to investigate whether ToM skills were related to VMPFC gray matter volume (GMV). Standardized neuropsychological measures were used to assess global cognition. Twenty-one schizophrenia and 17 healthy control subjects participated.

RESULTS

Between-group behavioral analyses showed that, as compared with healthy participants, schizophrenia participants had worse ToM performance and lower self-reported ToM processing in daily life. The between-group analysis of GMV showed that schizophrenia participants had less VMPFC GMV than healthy participants. Moreover, among schizophrenia participants, all three measures of ToM processing were associated with VMPFC GMV, such that worse ToM skills were related to less VMPFC GMV. This association remained strong for self-reported and interview-rated ToM skills, even when controlling for the influence of global cognition.

CONCLUSIONS

The findings suggest that among individuals with schizophrenia, reduced VMPFC GMV is associated with deficits using ToM skills to enhance social relationships.