Mega-analysis of the brain-age gap in substance use disorder: An ENIGMA Addiction working group study.

Background And Aims: The brain age gap (BAG), calculated as the difference between a machine learning model-based predicted brain age and chronological age, has been increasingly investigated in psychiatric disorders. Tobacco and alcohol use are associated with increased BAG; however, no studies have compared global and regional BAG across substances other than alcohol and tobacco. This study aimed to compare global and regional estimates of brain age in individuals with substance use disorders and healthy controls.

Principal component analysis as an efficient method for capturing multivariate brain signatures of complex disorders-ENIGMA study in people with bipolar disorders and obesity.

Multivariate techniques better fit the anatomy of complex neuropsychiatric disorders which are characterized not by alterations in a single region, but rather by variations across distributed brain networks. Here, we used principal component analysis (PCA) to identify patterns of covariance across brain regions and relate them to clinical and demographic variables in a large generalizable dataset of individuals with bipolar disorders and controls. We then compared performance of PCA and clustering on identical sample to identify which methodology was better in capturing links between brain and clinical measures.

Participants' experiences of a counsellor-supported PTSD Coach intervention in a resource-constrained setting.

We explored participants' experiences of a counsellor-supported PTSD Coach mobile application intervention (PTSD Coach-CS) in a randomised controlled trial. PTSD Coach-CS participants, who received the intervention and self-completed a custom-designed questionnaire at intervention completion were included ( = 25; female = 20; ages 19-59; isiXhosa = 22). This questionnaire comprised questions regarding the feasibility, acceptability and potential impact of the PTSD Coach-CS intervention, and general psychological support in our setting.

Patterns of subregional cerebellar atrophy across epilepsy syndromes: An ENIGMA-Epilepsy study.

Objective: The intricate neuroanatomical structure of the cerebellum is of longstanding interest in epilepsy, but has been poorly characterized within the current corticocentric models of this disease. We quantified cross-sectional regional cerebellar lobule volumes using structural magnetic resonance imaging in 1602 adults with epilepsy and 1022 healthy controls across 22 sites from the global ENIGMA-Epilepsy working group.

Methods: A state-of-the-art deep learning-based approach was employed that parcellates the cerebellum into 28 neuroanatomical subregions.

Patterns of subregional cerebellar atrophy across epilepsy syndromes: An ENIGMA-Epilepsy study.

Objective: The intricate neuroanatomical structure of the cerebellum is of longstanding interest in epilepsy, but has been poorly characterized within the current cortico-centric models of this disease. We quantified cross-sectional regional cerebellar lobule volumes using structural MRI in 1,602 adults with epilepsy and 1,022 healthy controls across twenty-two sites from the global ENIGMA-Epilepsy working group.

Methods: A state-of-the-art deep learning-based approach was employed that parcellates the cerebellum into 28 neuroanatomical subregions.

Association between cannabis use and symptom dimensions in schizophrenia spectrum disorders: an individual participant data meta-analysis on 3053 individuals.

Background: The association between cannabis use and positive symptoms in schizophrenia spectrum disorders is well documented, especially via meta-analyses. Yet, findings are inconsistent regarding negative symptoms, while other dimensions such as disorganization, depression, and excitement, have not been investigated. In addition, meta-analyses use aggregated data discarding important confounding variables which is a source of bias.

Cortical morphology in patients with the deficit and non-deficit syndrome of schizophrenia: a worldwide meta- and mega-analyses.

Converging evidence suggests that schizophrenia (SZ) with primary, enduring negative symptoms (i.e., Deficit SZ (DSZ)) represents a distinct entity within the SZ spectrum while the neurobiological underpinnings remain undetermined.

Country-level gender inequality is associated with structural differences in the brains of women and men.

Gender inequality across the world has been associated with a higher risk to mental health problems and lower academic achievement in women compared to men. We also know that the brain is shaped by nurturing and adverse socio-environmental experiences. Therefore, unequal exposure to harsher conditions for women compared to men in gender-unequal countries might be reflected in differences in their brain structure, and this could be the neural mechanism partly explaining women's worse outcomes in gender-unequal countries.

Differences in white matter microstructure in first-episode schizophrenia spectrum disorders vs healthy volunteers and their association with cognition.

Objective: Both cognitive impairment and alterations in white matter tissue microstructure are well recognised in schizophrenia. We investigated whether differences in white matter microstructure underpin cognitive impairments in patients with first-episode schizophrenia spectrum disorders when controlling for multiple confounding factors.

Methods: We employed a cross-sectional study design and compared fractional anisotropy (FA) between individuals diagnosed with first- episode schizophrenia spectrum disorders (FES) (n = 68) and matched healthy controls (n = 120).

The impact of prenatal alcohol and/or tobacco exposure on brain structure in a large sample of children from a South African birth cohort.

Background: Neuroimaging studies have emphasized the impact of prenatal alcohol exposure (PAE) on brain development, traditionally in heavily exposed participants. However, less is known about how naturally occurring community patterns of PAE (including light to moderate exposure) affect brain development, particularly in consideration of commonly occurring concurrent impacts of prenatal tobacco exposure (PTE).

Methods: Three hundred thirty-two children (ages 8 to 12) living in South Africa's Cape Flats townships underwent structural magnetic resonance imaging.

Childhood trauma exposure and reward processing in healthy adults: A functional neuroimaging study.

The association between childhood trauma exposure and risk of developing psychopathology may in part be mediated by the effects of chronic stress on dopaminergic neurotransmission. However, little is known about the differential effects of distinct trauma types on reward processing, particularly in adults without concurrent medical or psychiatric disorders. We examined the association of childhood trauma exposure, including the differential effects of abuse and neglect, with reward processing in healthy adults (n = 114).

The trajectories and correlates of two negative symptom subdomains in first-episode schizophrenia.

Background: Recent studies suggest a two-factor structure for negative symptoms as assessed by the Positive and Negative Syndrome Scale (PANSS) in schizophrenia, namely experiential and expressive subdomains. Little is known about their clinical correlates and treatment trajectories.

Objectives: We sought to replicate the two factor-analysis derived subdomains for PANSS negative symptoms in schizophrenia and to assess their independent demographic, premorbid and treatment-related characteristics.

The associations of cannabis and methamphetamine use with cognitive performance over the first 2 years of treatment in schizophrenia spectrum disorders.

Aim: Cognitive deficits are a core feature of schizophrenia, and comorbid substance use may be a contributory factor. Methamphetamine use has been associated with cognitive impairment in schizophrenia, while associations with cannabis use are less clear-cut. This study aimed to investigate the associations of cannabis and methamphetamine use with cognitive performance in first-episode schizophrenia spectrum disorders over the first 2 years of treatment.

Cannabis use and clinical outcome in people with first-episode schizophrenia spectrum disorders over 24 months of treatment.

Cannabis use is associated with an unfavourable course of illness in schizophrenia, although several factors may confound this association. In this longitudinal study, we explored the influence of cannabis use on baseline symptom severity and treatment outcomes in 98 patients with first-episode schizophrenia spectrum disorders treated with a long acting injectable antipsychotic over 24 months. Using mixed models for repeated measures, we compared visit-wise changes in psychopathology, social and occupational functioning and quality of life between recent/current cannabis users (n=45) and non-users (n=53).

The association between childhood trauma and treatment outcomes in schizophrenia spectrum disorders.

Childhood trauma exposure has been associated with poorer treatment outcomes in schizophrenia. Most studies to date have been conducted in naturalistic settings in which the outcome may have been mediated by factors such as poor adherence and substance abuse. We compared the effects of high vs low childhood trauma exposure on the treatment response over 24 months in 78 patients with first-episode schizophrenia spectrum disorders who received standardised treatment with a long acting injectable antipsychotic.

Neurological soft signs in first-episode schizophrenia: State- and trait-related relationships to psychopathology, cognition and antipsychotic medication effects.

Background: Neurological soft signs (NSS) are proposed to represent both state- and trait-related features of schizophrenia.

Method: We assessed the course of NSS with the Neurological Evaluation Scale (NES) over 12months of standardised treatment in 126 patients with first-episode schizophrenia, schizophreniform or schizoaffective disorder, and evaluated their state- and trait-related associations with psychopathology, functionality, cognition and antipsychotic treatment. We considered change scores from baseline to be state-related and endpoint scores to be trait-related.