White matter correlates of impulsivity in frontal lobe and their associations with treatment response in first-episode schizophrenia

Diffusion magnetic resonance imaging for treatment response prediction in schizophrenia spectrum disorders: A systematic review

A substantial portion of schizophrenia spectrum disorder (SSD) patients exhibit resistance to antipsychotic treatments, emphasizing the need for reliable treatment response biomarkers. Previous magnetic resonance imaging (MRI) studies have identified various imaging predictors in SSD. This study focuses on evaluating the effectiveness of diffusion MRI sequences, diffusion tensor imaging (DTI) and diffusion-weighted imaging (DWI), in predicting antipsychotic response in SSD patients. A systematic search for relevant articles was conducted in PubMed, Embase, Scopus, and Web of Science on February 11, 2024. Twelve studies involving a total of 742 patients were systematically reviewed. The baseline DTI/DWI biomarkers revealed significant associations with antipsychotic treatment response. Notably a consistent negative link was found between response and baseline fractional anisotropy (FA) in fronto-temporo-limbic white matter tracts, specifically the superior longitudinal fasciculus, providing moderate-level evidence. In addition, weak-level evidence was found for the negative association between the treatment response and baseline FA in the corpus callosum, internal, and external capsule tracts. Collectively, this review demonstrated that obtaining pre-treatment brain diffusion MRI scans, particularly from white matter tracts of fronto-temporo-limbic network, can assist in delineating the treatment response trajectory in patients with SSD. However, additional larger randomized controlled trials are required to further substantiate these findings.

Neurotransmission-related gene expression in the frontal pole is altered in subjects with bipolar disorder and schizophrenia

The frontal pole (Brodmann area 10, BA10) is the largest cytoarchitectonic region of the human cortex, performing complex integrative functions. BA10 undergoes intensive adolescent grey matter pruning prior to the age of onset for bipolar disorder (BP) and schizophrenia (SCHIZ), and its dysfunction is likely to underly aspects of their shared symptomology. In this study, we investigated the role of BA10 neurotransmission-related gene expression in BP and SCHIZ. We performed qPCR to measure the expression of 115 neurotransmission-related targets in control, BP, and SCHIZ postmortem samples (n = 72). We chose this method for its high sensitivity to detect low-level expression. We then strengthened our findings by performing a meta-analysis of publicly released BA10 microarray data (n = 101) and identified sources of convergence with our qPCR results. To improve interpretation, we leveraged the unusually large database of clinical metadata accompanying our samples to explore the relationship between BA10 gene expression, therapeutics, substances of abuse, and symptom profiles, and validated these findings with publicly available datasets. Using these convergent sources of evidence, we identified 20 neurotransmission-related genes that were differentially expressed in BP and SCHIZ in BA10. These results included a large diagnosis-related decrease in two important therapeutic targets with low levels of expression, HTR2B and DRD4, as well as other findings related to dopaminergic, GABAergic and astrocytic function. We also observed that therapeutics may produce a differential expression that opposes diagnosis effects. In contrast, substances of abuse showed similar effects on BA10 gene expression as BP and SCHIZ, potentially amplifying diagnosis-related dysregulation.

A study of emotional intelligence in an Egyptian sample of offspring of patients with schizophrenia

Background

Emotional intelligence is usually a construct measured in healthy children, now it may be used for relatives of schizophrenia, and considered as trait marker for schizophrenia. Offspring of parents with schizophrenia are considered children with high familial risk for major mental disorder. The aim of the study is to assess emotional intelligence in a group of off springs of a parent with schizophrenia and compare them to healthy control subjects, and to find possible relation between emotional intelligence in offspring and profile of symptoms in schizophrenic parents.

Results

Offspring of parents with schizophrenia had lower scores of emotional intelligences than their matched controls in emotion perception, self-esteem, low impulsivity and emotion regulation’s subsets of TEIQue-CF. There was correlation between offspring trait emotional intelligence and their parent’s duration of illness. There was no correlation found between schizophrenia severity in the parents and their offspring’s trait emotional intelligence.

Conclusions

Offspring of parents with schizophrenia had impaired trait emotional intelligence in some of its facets when compared to normal healthy subjects.

The factor structure of the Barratt Impulsiveness Scale (BIS-11) and correlates of impulsivity among outpatients with schizophrenia and other psychotic disorders in Singapore

BACKGROUND

Impulsivity has been linked to risky behaviours amongst patients with schizophrenia or other psychotic disorders. However, there is a dearth of studies examining impulsivity amongst this population in Singapore. Moreover, to date, scales to measure impulsivity have not been validated in this population. The present study seeks to examine the underlying factor structure of the Barratt Impulsiveness Scale (BIS-11) and explore sociodemographic and clinical correlates of impulsivity within this group.

METHODS

Confirmatory factor analyses (CFA) were conducted to test factor structures of the BIS-11 proposed in extant literature. However, due to poor fit statistics, the sample (n = 397) was split into two groups, with Exploratory Factor Analyses (EFA) conducted in the first subgroup (n = 200). The final model of the EFA was then tested within the second subgroup (n = 197) with CFA. Multivariable linear regressions were conducted to examine sociodemographic and clinical correlates of each underlying factor.

RESULTS

CFA indicated a three-factor structure amongst 16-items of the BIS-11 with acceptable fit: i) Non-planning impulsivity (5-items; α = 0.94), ii) Motor impulsiveness (6-items α = 0.84), and iii) Lack of self-control (5-items, α = 0.85). Lower education was associated with higher non-planning impulsivity. While age, ethnicity, marital status, and general psychiatric symptom severity were significant correlates of motor impulsiveness, problematic alcohol use and general psychiatric symptom severity were related to a greater lack of self-control.

CONCLUSION

Factor structures of the BIS-11 suggested by extant literature were not applicable, and we propose an alternative factor structure for BIS-11. Significant correlates of impulsivity are highlighted, and avenues for future research are suggested.