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

Insight in obsessive-compulsive disorder: conception, clinical characteristics, neuroimaging, and treatment

Obsessive-compulsive disorder (OCD) is a chronic disabling disease with often unsatisfactory therapeutic outcomes. The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) has broadened the diagnostic criteria for OCD, acknowledging that some OCD patients may lack insight into their symptoms. Previous studies have demonstrated that insight can impact therapeutic efficacy and prognosis, underscoring its importance in the treatment of mental disorders, including OCD. In recent years, there has been a growing interest in understanding the influence of insight on mental disorders, leading to advancements in related research. However, to the best of our knowledge, there is dearth of comprehensive reviews on the topic of insight in OCD. In this review article, we aim to fill this gap by providing a concise overview of the concept of insight and its multifaceted role in clinical characteristics, neuroimaging mechanisms, and treatment for OCD.

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.

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.

Abnormal Brain Structure Morphology in Early-Onset Schizophrenia

With less exposure to environmental and medication influences, individuals with early-onset schizophrenia (EOS) may provide valuable evidence to study the pathogenesis and phenotypic pattern of schizophrenia.T1-weighted magnetic resonance images were collected in 60 individuals with EOS and 40 healthy controls. Voxel-based morphometry and surface-based morphometry analyzes were performed. Gray matter volume, cortical thickness and cortical surface area were compared between the EOS and healthy controls and among schizophrenia subgroups (with or without family history of schizophrenia). Compared with healthy controls, the EOS group had reduced gray matter volume in the bilateral middle temporal gyrus and reduced cortical thickness in several brain regions. The sporadic early onset schizophrenia and the familial early onset schizophrenia showed different brain structure morphology. These findings suggest that abnormal brain structure morphology, especially in the temporal and frontal lobes, may be an important pathophysiological feature of EOS.

Correlations between cortical gyrification and schizophrenia symptoms with and without comorbid hostility symptoms

INTRODUCTION

Interest in identifying the clinical implications of the neuropathophysiological background of schizophrenia is rising, including changes in cortical gyrification that may be due to neurodevelopmental abnormalities. Inpatients with schizophrenia can show abnormal gyrification of cortical regions correlated with the symptom severity.

METHODS

Our study included 36 patients that suffered an acute episode of schizophrenia and have undergone structural magnetic resonance imaging (MRI) to calculate the local gyrification index (LGI).

RESULTS

In the whole sample, the severity of symptoms significantly correlated with higher LGI in different cortical areas, including bilateral frontal, cingulate, parietal, temporal cortices, and right occipital cortex. Among these areas, patients with low hostility symptoms (LHS) compared to patients with high hostility symptoms (HHS) showed significantly lower LGI related to the severity of symptoms in bilateral frontal and temporal lobes.

DISCUSSION

The severity of psychopathology correlated with higher LGI in large portions of the cerebral cortex, possibly expressing abnormal neural development in schizophrenia. These findings could pave the way for further studies and future tailored diagnostic and therapeutic strategies.

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.

Long term cortical thickness changes after a first episode of non- affective psychosis: The 10 year follow-up of the PAFIP cohort

Cortical thickness has been widely studied in individuals with schizophrenia and, in particular, first-episode psychosis. Abnormalities have been described, although there is, to date, a lack of consensus regarding changes across time and correlations with clinical and functional outcomes of the illness. One hundred and twenty-three first-episode psychosis patients and 74 healthy volunteers were subjected to magnetic resonance imaging scans and clinical and functional assessments by different scales at four consecutive visits during a 10 year follow-up period. Linear mixed effects models were applied to our data to compute cortical thickness changes over time in (1) schizophrenia patients versus healthy controls and (2) in patients with good versus poor functional outcome. The associations between cortical thickness percentage changes and clinical and functional status at 10 years were also assessed. The patients presented a thinner cortex than the controls at baseline (b's = -0.06; q ≤ 0.00023) with non-significant coefficients for the interaction term (follow-up time x group) (b's = -0.001; q ≥ 0.681). Poor functioning patients presented statistically significant coefficients for the interaction term (follow-up time x functionality) (left: b = -0.005, q = 0.019; right: b = -0.005, q = 0.022). In contrast, no correlations were found between cortical thickness measurements and clinical variables at 10 years. Overall, there were widespread thickness anomalies in first-episode psychosis patients across cortical regions that remained stable across time. Progressive thickness changes were related to patient functional outcomes, with progressive and steeper cortical thinning in patients with worse functional outcomes and a stabilization in those with better outcomes.

Progression of neuroanatomical abnormalities after first-episode of psychosis: A 3-year longitudinal sMRI study

The location, extent and progression of longitudinal morphometric changes after first-episode of psychosis (FEP) remains unclear. We investigated ventricular and cortico-subcortical regions over a 3-year period in FEP patients compared with healthy controls. High resolution 1.5T T1-weighted MR images were obtained at baseline from 28 FEP patients at presentation and 28 controls, and again after 3-years. The longitudinal FreeSurfer pipeline (v.5.3.0) was used for regional volumetric and cortical reconstruction image analyses. Repeated-measures ANCOVA and vertex-wise linear regression analyses compared progressive changes between groups in subcortical structures and cortical thickness respectively. Compared with controls, patients displayed progressively reduced volume of the caudate [F (1,51)=5.86, p=0.02, Hedges' g=0.66], putamen [F (1,51)=6.06, p=0.02, g=0.67], thalamus [F (1,51)=6.99, p=0.01, g=0.72] and increased right lateral ventricular volume [F (1, 51)=4.03, p=0.05], and significantly increased rate of cortical thinning [F (1,52)=5.11, p=0.028)] at a mean difference of 0.84% [95% CI (0.10, 1.59)] in the left lateral orbitofrontal region over the 3-year period. In patients, greater reduction in putamen volume over time was associated with lower cumulative antipsychotic medication dose (r=0.49, p=0.01), and increasing lateral ventricular volume over time was associated with worsening negative symptoms (r=0.41, p=0.04) and poorer global functioning (r= -0.41, p=0.04). This study demonstrates localised progressive structural abnormalities in the cortico-striato-thalamo-cortical circuit after the onset of psychosis, with increasing ventricular volume noted as a neuroanatomical marker of poorer clinical and functional outcome.

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.

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.

Cognitive capacity similarly predicts insight into symptoms in first- and multiple-episode psychosis

BACKGROUND

Lack of insight is a frequent characteristic of psychotic disorders, both in patients who recently experienced a first episode of psychosis (FEP) and those who experience recurrent multiple episodes (MEP). Insight is a multifaceted construct: its clinical form notably includes the unawareness of being ill, of symptoms, and of the need for treatment. Cognitive capacity is among the key determinants of insight into symptoms, but less is known about whether stage of illness (FEP vs. MEP) moderates this association.

METHODS

Our aim is to evaluate the association between cognitive capacity and symptom unawareness using structural equation modeling and moderated multiple regression. A total of 193 FEP and MEP patients were assessed using the CogState battery and the Scale to Assess Unawareness of Mental Disorder.

RESULTS

Analyses suggest that cognitive capacity accounts for a relatively small proportion of the total variation in symptom unawareness (6.4%). There was no evidence to suggest a moderating effect of stage of illness on this association.

CONCLUSIONS

The effect of general cognitive capacity on symptom unawareness is relatively small, and this basic relation was unrelated to stage of illness. It is possible that stage of illness could moderate this association only for certain facets of insight not assessed in this study (e.g., unawareness of the need for treatment).

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.

Level of Insight in Patients With Obsessive-Compulsive Disorder: An Exploratory Comparative Study Between Patients With "Good Insight" and "Poor Insight"

Introduction: Insight may be defined as the ability to perceive and evaluate external reality and to separate it from its subjective aspects. It also refers to the ability to self-assess difficulties and personal qualities. Insight may be a predictor of success in the treatment of obsessive-compulsive disorder (OCD), so that individuals with poor insight tend to become refractory to treatment. The objective of this study is to investigate factors associated with poor insight in individuals with OCD. Methods: This cross-sectional exploratory study used the Brown Belief Assessment Scale as a parameter for the creation of the comparison groups: individuals who obtained null scores (zero) composed the group with preserved or good insight (n = 148), and those with scores above the 75% percentile composed the group with poor insight (n = 124); those with intermediate scores were excluded. Sociodemographic characteristics and clinical and psychopathological aspects, intrinsic and extrinsic to the typical symptoms of OCD, were compared in a univariate analysis. A logistic regression was used to determine which factors associated with critical judgment remained significant. Results: Individuals in the poor insight group differed from those with good insight in regard to: more prevalent use of neuroleptics (p = 0.05); higher untreated time interval (p < 0.001); higher total Yale-Brown obsessive-compulsive scale score and the obsessions and compulsions factors (all factors with p < 0.001); higher dimensional Yale-Brown obsessive-compulsive scale total and dimensional scores (p from 0.04 to 0.001); higher prevalence of contamination/cleaning (p = 0.006) and hoarding (p < 0.001) symptoms dimensions; more prevalent sensory phenomena (p = 0.023); higher levels of depression (p = 0.007); and more prevalent comorbidity with bipolar affective disorder (p = 0.05) and post-traumatic stress disorder (PTSD) (p = 0.04). After analyzing the logistic regression, we conclude that the most important factors associated with poor insight are: the presence of any sensory phenomena (OR: 2.24), use of neuroleptics (OR: 1.66), and hoarding symptoms (OR: 1.15). Conclusion: The variability of insight in patients with OCD seems to be an important psychopathological characteristic in the differentiation of possible subtypes of OCD, since the poor insight is associated with sensory phenomena and greater use of neuroleptics, which makes it possible to conjecture the role of dopaminergic neurocircuits in the neurobiology of this disorder. In addition, there is also an association with the symptoms of hoarding content, admittedly one of the symptomatic contents with less response to conventional OCD treatments. Studies based on neurobiological aspects such as neuroimaging and neuropsychology may help to elucidate more consistently the role of insight in patients with OCD and the repercussions concerning available treatments.