Widespread intra-axonal signal fraction abnormalities in bipolar disorder from multicompartment diffusion MRI: Sensitivity to diagnosis, association with clinical features and pharmacologic treatment.

Despite diffusion tensor imaging (DTI) evidence for widespread fractional anisotropy (FA) reductions in the brain white matter of patients with bipolar disorder, questions remain regarding the specificity and sensitivity of FA abnormalities as opposed to other diffusion metrics in the disorder. We conducted a whole-brain voxel-based multicompartment diffusion MRI study on 316 participants (i.e., 158 patients and 158 matched healthy controls) employing four diffusion metrics: the mean diffusivity (MD) and FA estimated from DTI, and the intra-axonal signal fraction (IASF) and microscopic axonal parallel diffusivity (Dpar) derived from the spherical mean technique. Our findings provide novel evidence about widespread abnormalities in other diffusion metrics in BD. An extensive overlap between the FA and IASF results suggests that the lower FA in patients may be caused by a reduced intra-axonal volume fraction or a higher macromolecular content in the intra-axonal water. We also found a diffuse alteration in MD involving white and grey matter tissue and more localised changes in Dpar. A Machine Learning analysis revealed that FA, followed by IASF, were the most helpful metric for the automatic diagnosis of BD patients, reaching an accuracy of 72%. Number of mood episodes, age of onset/duration of illness, psychotic symptoms, and current treatment with lithium, antipsychotics, antidepressants, and antiepileptics were all significantly associated with microstructure abnormalities. Lithium treatment was associated with less microstructure abnormality.

Differential failure to deactivate the default mode network in unipolar and bipolar depression.

OBJECTIVES: Neuroimaging studies have revealed evidence of brain functional abnormalities in bipolar depressive disorder (BDD) and major depressive disorder (MDD). However, few studies to date have compared these two mood disorders directly. METHODS: Matched groups of 26 BDD type I patients, 26 MDD patients and 26 healthy controls underwent functional magnetic resonance imaging (fMRI) while performing the n-back working memory task. A whole-brain ANOVA was used to compare the three groups and clusters of significant difference were examined further using region-of-interest (ROI) analysis. RESULTS: The whole-brain ANOVA revealed a single cluster of significant difference in the medial frontal cortex. The BDD and MDD patients both showed failure to deactivate in this area compared to the controls. The BDD patients showed significantly greater failure of deactivation than the MDD patients, which was not accounted for by differences in severity or chronicity of illness between them. CONCLUSIONS: Failure of deactivation, considered to reflect default mode network dysfunction, is present to a greater extent in bipolar than unipolar depression. The study of this network may be useful in the search for brain markers that distinguish the two disorders.

Psychometric properties of the Spanish version of the Health of Nation Outcome Scales for schizophrenia patients.

Accessible Summary What is known on the subject? Functioning is one of the most affected areas in schizophrenia. Social, occupational and personal domains are affected, and these deficits are responsible for a major part of the disability associated with the disorder. There are several instruments to measure functioning, but the HoNOS provides a wide assessment of impairment in 12 areas of functioning. What does the paper add to existing knowledge? The Spanish version of the HoNOS shows good properties in terms of reliability and validity for use in schizophrenia patients. Although some authors divide the scale according to proposed underlying dimensions, in schizophrenia this division may not be appropriate. What are the implications for practice? A reliable and easy-to-use measure of impairment in different areas of functioning is useful for optimizing the treatment and rehabilitation of patients with schizophrenia. ABSTRACT: INTRODUCTION: The HoNOS scale was designed for the assessment of psychosocial impairment in various domains. While it is widely used in psychiatric settings, it has not been validated in Spanish for use in patients with schizophrenia. AIM: To examine the psychometric properties of the Spanish version of the HoNOS scale in a sample of schizophrenia patients. METHOD: A total of 194 individuals aged 18 to 65 with schizophrenia spectrum diagnoses were evaluated using the HoNOS. Illness severity and level of functioning were also assessed. RESULTS: The HoNOS showed moderate internal consistency, good inter-observer reliability and good test-retest reliability. Factor analysis revealed an internal structure consisting of four factors, with item distribution differing from the theoretical dimensions proposed for the original scale. DISCUSSION: The Spanish version of the HoNOS scale is a reliable and valid instrument for assessing psychosocial impairment in individuals diagnosed with schizophrenia spectrum disorders. However, further research is needed to determine its internal structure more accurately. IMPLICATIONS FOR PRACTICE: The HoNOS scale provides researchers and clinicians with a valid measure of impairment in twelve different domains, which can facilitate and guide the treatment of schizophrenia patients.

The relationship between cognition and functioning in Bipolar Disorder: An investigation using functional imaging during working memory performance.

The psychosocial functioning of individuals suffering from bipolar disorder (BD) has a significant impact on prognosis and quality of life. The aim of this study was to assess brain functional correlates of psychosocial functioning in BD individuals during the performance of a working memory task. Sixty-two subjects (31 euthymic BD individuals and 31 matched healthy controls) underwent structural and functional magnetic resonance imaging scanning while performing the 1- and 2-back versions of the n-back task (1-back and 2-back). The Functional Assessment Short Test (FAST) and its subdomains were used to assess functioning. Whole brain analysis revealed only overall activation differences between BD patients and healthy controls, but the patients showed failure of de-activation in the medial frontal cortex. Six clusters of significant inverse correlation with the FAST scores were found in the dorsolateral prefrontal cortex, the superior parietal cortex, and temporo-occipital regions bilaterally, and in the left inferior frontal cortex. Cognitive and occupational functioning were the subdomains most significantly associated with brain activation in these clusters. The results suggest that poor psychosocial functioning in BD individuals is associated with hypoactivation in a range of cortical regions, including the fronto-parietal working memory network and inferior temporo-occipital regions.

Human-specific evolutionary markers linked to foetal neurodevelopment modulate brain surface area in schizophrenia.

Schizophrenia may represent a trade-off in the evolution of human-specific ontogenetic mechanisms that guide neurodevelopment. Human Accelerated Regions (HARs) are evolutionary markers functioning as neurodevelopmental transcription enhancers that have been associated with brain configuration, neural information processing, and schizophrenia risk. Here, we have investigated the influence of HARs' polygenic load on neuroanatomical measures through a case-control approach (128 patients with schizophrenia and 115 controls). To this end, we have calculated the global schizophrenia Polygenic Risk Score (Global PRSSZ) and that specific to HARs (HARs PRSSZ). We have also estimated the polygenic burden restricted to the HARs linked to transcriptional regulatory elements active in the foetal brain (FB-HARs PRSSZ) and the adult brain (AB-HARs PRSSZ). We have explored the main effects of the PRSs and the PRSs x diagnosis interactions on brain regional cortical thickness (CT) and surface area (SA). The results indicate that a higher FB-HARs PRSSZ is associated with patients' lower SA in the lateral orbitofrontal cortex, the superior temporal cortex, the pars triangularis and the paracentral lobule. While noHARs-derived PRSs show an effect on the risk, our neuroanatomical findings suggest that the human-specific transcriptional regulation during the prenatal period underlies SA variability, highlighting the role of these evolutionary markers in the schizophrenia genomic architecture.

Validity of the Functioning Assessment Short Tests (FAST), in patients with schizophrenia.

INTRODUCTION: Functional impairment in schizophrenia is one of the main features of the disorder and implies a great impact on the patient's quality of life. The Brief Functioning Assessment Scale (FAST), originally validated in bipolar disorder, has also been validated for its application in other mental disorders. However, we only found one study on the reliability and validity of the Brazilian version in schizophrenia. The purpose of this study was to analyze the psychometric properties of the Spanish version of the FAST in patients diagnosed with schizophrenia. MATERIAL AND METHODS: A total of 226 patients with a diagnosis of schizophrenia were evaluated by mean the FAST, the GAF and the self-care requirements scale (ERA). Scale properties were analyzed in terms of internal consistency, inter-observer agreement and test-retest reliability. Convergent validity with the GAF and ERA scales was also analyzed, as well as construct validity by means of a Confirmatory Factor Analysis (CFA). RESULTS: For the total scale, the results showed high internal consistency (Cronbach's Alpha of, 87), as well as good inter-observer (ICC=,86) and test-retest (ICC=,77) agreement. Concurrent validity with the GAF scale was discrete (r=-,32; P<,001) and with the ERA scale was moderate (r=,50; P<,001). CFA showed an internal structure that matched the six factors proposed by the original scale, with a good level of item saturation for each factor. CONCLUSIONS: The FAST scale showed good psychometric properties in terms of reliability and validity in its Spanish version for its application in patients with schizophrenia. It can be considered as a good tool to assess different areas of functional impairment in clinical practice and research.

The role of educational attainment and brain morphology in major depressive disorder: Findings from the ENIGMA major depressive disorder consortium.

Brain structural abnormalities and low educational attainment are consistently associated with major depressive disorder (MDD), yet there has been little research investigating the complex interaction of these factors. Brain structural alterations may represent a vulnerability or differential susceptibility marker, and in the context of low educational attainment, predict MDD. We tested this moderation model in a large multisite sample of 1958 adults with MDD and 2921 controls (aged 18 to 86) from the ENIGMA MDD working group. Using generalized linear mixed models and within-sample split-half replication, we tested whether brain structure interacted with educational attainment to predict MDD status. Analyses revealed that cortical thickness in a number of occipital, parietal, and frontal regions significantly interacted with education to predict MDD. For the majority of regions, models suggested a differential susceptibility effect, whereby thicker cortex was more likely to predict MDD in individuals with low educational attainment, but less likely to predict MDD in individuals with high educational attainment. Findings suggest that greater thickness of brain regions subserving visuomotor and social-cognitive functions confers susceptibility to MDD, dependent on level of educational attainment. Longitudinal work, however, is ultimately needed to establish whether cortical thickness represents a preexisting susceptibility marker. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Midline Brain Abnormalities Across Psychotic and Mood Disorders.

Patients with schizophrenia are known to have increased prevalence of abnormalities in midline brain structures, such as a failure of the septum pellucidum to fuse (cavum septum pellucidum) and the absence of the adhesio interthalamica. This is the first study to investigate the prevalence of these abnormalities across a large multidiagnostic sample. Presence of cavum septum pellucidum and absence of the adhesio interthalamica was assessed in 639 patients with chronic schizophrenia, delusional disorder, schizoaffective disorder, bipolar disorder, major depressive disorder, or a first episode of psychosis, mania or unipolar depression. This was compared with 223 healthy controls using logistic-regression-derived odds ratios (OR). Patients with psychotic or mood disorders showed an increased prevalence of both abnormalities (OR of cavum septum pellucidum = 2.1, OR of absence of the adhesio interthalamica = 2.6, OR of both cavum septum pellucidum and absence of the adhesio interthalamica = 3.8, all P < .001). This increased prevalence was separately observed in nearly all disorders as well as after controlling for potential confounding factors. This study supports a general increased prevalence of midline brain abnormalities across mood and psychotic disorders. This nonspecificity may suggest that these disorders share a common neurodevelopmental etiology.