Grey matter covariation and the role of emotion reappraisal in mental wellbeing and resilience after early life stress exposure

ReNeuWell mental well-being app: protocol for a randomised controlled trial

INTRODUCTION

The field of mental well-being interventions includes numerous studies of smartphone app-based programs, but there is a research-to-retail gap where many studies pertain to apps that are not publicly available, not used as standalone programs, or not tested in the general population, and many publicly available apps (or their proprietary in-app measures) have yet to be submitted to empirical testing. Furthermore, few well-being apps offer multicomponent interventions, despite such interventions having demonstrated efficacy outside the smartphone context. In response to these openings in the literature and marketplace, we have developed ReNeuWell, an iPhone app designed to measure the user's mental well-being (via the validated Composure, Own-worth, Mastery, Positivity, Achievement and Satisfaction for Well-being (COMPAS-W) scale) and improve their well-being via a personalised, multicomponent program of activities informed by the peer-reviewed evidence base. This article describes the protocol for the preregistered randomised controlled trial (RCT) of ReNeuWell, to test the app in adult participants from the general population of Apple App Store users. It is hypothesised that ReNeuWell users will experience significant increases in mental well-being and decreases in mental distress over the 6-12-week trial period, relative to users of an active control version of the app.

METHODS AND ANALYSIS

The RCT will recruit participants from Apple Store users who choose to download ReNeuWell in the normal course of browsing the marketplace. Following consent, the app will randomly allocate participants to receive either the full version of the app or the active control version. The full version assesses the user's well-being via the validated COMPAS-W scale, provides feedback on their well-being across six dimensions and creates a personalised schedule of daily positive psychology activities designed to enhance well-being along each dimension. Participants will be instructed to use the app for at least 10 min (at least one activity) per day for the first 6 weeks, and as they wish for the following 6 weeks. Trial outcomes will be measured via in-app surveys administered in weeks 1, 6 and 12. Data collection will begin when the app is officially launched on the Apple Store. Data will be analysed using linear mixed models to estimate condition-by-time interaction effects on the primary and secondary outcomes, and to assess whether any such effects are themselves moderated by other key variables.

ETHICS AND DISSEMINATION

This protocol has been approved by the Human Research Ethics Committee of the University of New South Wales (reference number: HC210302). Trial outcomes will be published in accordance with the preregistered protocol described here, both in the peer-reviewed literature and on the registry website.

TRIAL REGISTRATION NUMBER

This protocol was preregistered with the Australian New Zealand Clinical Trials Registry (registration approved on 4 August 2021; trial ID number: ACTRN12621001014842p).

Characterising mental wellbeing and associations with subcortical grey matter volume at short intervals in early adolescence

This temporally rich, longitudinal study of early adolescents (N = 88, 277 datasets, 12-13 years) investigated the relationship between bilateral subcortical grey matter volume (GMV) in the hippocampus, amygdala, accumbens-area, caudate, putamen and pallidum with self-reported mental wellbeing at four timepoints, across 12 months. Generalised Estimating Equations (GEE) revealed (1) higher 'total wellbeing' was associated with smaller left caudate and larger left accumbens-area; (2) higher eudaimonic wellbeing was associated with smaller left caudate and larger right caudate; and (3) higher hedonic wellbeing was associated with larger left accumbens-area. Further analyses and plots highlighted different associations between GMV and wellbeing for adolescents who consistently experienced 'moderate-to-flourishing' wellbeing (n = 63, 201 datasets), compared with those who experienced 'languishing' wellbeing at any timepoint (n = 25, 76 datasets). These findings demonstrate several associations between subcortical GMV and measures of wellbeing, at short intervals in early adolescence. Taken together, sub-types of wellbeing appear uniquely associated with specific subcortical regions; and there may be a distinct neurobiological and wellbeing profile for adolescents who experience poorer wellbeing over the course of their first year(s) of secondary school. This study implicates the bilateral caudate and left accumbens-area as important targets for future research into the mental wellbeing of adolescents.

The moderating effect of recent positive and negative life events on the impact of early life stress on mental wellbeing and distress

Early life stress (ELS) significantly influences mental health in later stages of life. Yet it is unclear whether recent life events lessen or intensify the effects of ELS on present wellbeing and distress. We addressed this question in 1064 healthy community adults with a normative range of wellbeing and distress. We tested whether recent daily life events (DLE), occurring in the 12 months prior to assessment, moderated the association between effects of past ELS on present wellbeing and distress. Principal components analysis was first used on both ELS and DLE to determine the event types loading together on components. For wellbeing, we observed associations with the ELS component 'family conflict', and DLE components 'positive work changes', 'positive lifestyle changes', 'vacation', and 'negative work changes'. There was no evidence of these DLEs moderating the relationship between ELS and wellbeing. For distress, we found associations with three ELS components, 'interpersonal violence', 'personal health trauma', and 'peer conflict', of which 'interpersonal violence' showed an interaction with two negative DLE components - 'relationship problems' and 'sexual/pregnancy difficulties'. These findings suggest that the pervasive impact of interpersonal violence (childhood physical, sexual, and emotional abuse) on psychological distress is further compounded by maladaptive relationships in adulthood, which lead to higher distress; however, for wellbeing, the effects of ELS and DLE are independent. Our findings indicate a complex pattern of associations between life events and mental health, and highlight the importance of examining both wellbeing and distress outcomes, which may vary depending on the associations between early and recent life events.

Neural foundation of the diathesis-stress model: longitudinal gray matter volume changes in response to stressful life events in major depressive disorder and healthy controls

Recurrences of depressive episodes in major depressive disorder (MDD) can be explained by the diathesis-stress model, suggesting that stressful life events (SLEs) can trigger MDD episodes in individuals with pre-existing vulnerabilities. However, the longitudinal neurobiological impact of SLEs on gray matter volume (GMV) in MDD and its interaction with early-life adversity remains unresolved. In 754 participants aged 18-65 years (362 MDD patients; 392 healthy controls; HCs), we assessed longitudinal associations between SLEs (Life Events Questionnaire) and whole-brain GMV changes (3 Tesla MRI) during a 2-year interval, using voxel-based morphometry in SPM12/CAT12. We also explored the potential moderating role of childhood maltreatment (Childhood Trauma Questionnaire) on these associations. Over the 2-year interval, HCs demonstrated significant GMV reductions in the middle frontal, precentral, and postcentral gyri in response to higher levels of SLEs, while MDD patients showed no such GMV changes. Childhood maltreatment did not moderate these associations in either group. However, MDD patients who had at least one depressive episode during the 2-year interval, compared to those who did not, or HCs, showed GMV increases in the middle frontal, precentral, and postcentral gyri associated with an increase in SLEs and childhood maltreatment. Our findings indicate distinct GMV changes in response to SLEs between MDD patients and HCs. GMV decreases in HCs may represent adaptive responses to stress, whereas GMV increases in MDD patients with both childhood maltreatment and a depressive episode during the 2-year interval may indicate maladaptive changes, suggesting a neural foundation for the diathesis-stress model in MDD recurrences.

Searching Reproducible Brain Features using NeuroMark: Templates for Different Age Populations and Imaging Modalities

A primary challenge to the data-driven analysis is the balance between poor generalizability of population-based research and characterizing more subject-, study- and population-specific variability. We previously introduced a fully automated spatially constrained independent component analysis (ICA) framework called NeuroMark and its functional MRI (fMRI) template. NeuroMark has been successfully applied in numerous studies, identifying brain markers reproducible across datasets and disorders. The first NeuroMark template was constructed based on young adult cohorts. We recently expanded on this initiative by creating a standardized normative multi-spatial-scale functional template using over 100,000 subjects, aiming to improve generalizability and comparability across studies involving diverse cohorts. While a unified template across the lifespan is desirable, a comprehensive investigation of the similarities and differences between components from different age populations might help systematically transform our understanding of the human brain by revealing the most well-replicated and variable network features throughout the lifespan. In this work, we introduced two significant expansions of NeuroMark templates first by generating replicable fMRI templates for infants, adolescents, and aging cohorts, and second by incorporating structural MRI (sMRI) and diffusion MRI (dMRI) modalities. Specifically, we built spatiotemporal fMRI templates based on 6,000 resting-state scans from four datasets. This is the first attempt to create robust ICA templates covering dynamic brain development across the lifespan. For the sMRI and dMRI data, we used two large publicly available datasets including more than 30,000 scans to build reliable templates. We employed a spatial similarity analysis to identify replicable templates and investigate the degree to which unique and similar patterns are reflective in different age populations. Our results suggest remarkably high similarity of the resulting adapted components, even across extreme age differences. With the new templates, the NeuroMark framework allows us to perform age-specific adaptations and to capture features adaptable to each modality, therefore facilitating biomarker identification across brain disorders. In sum, the present work demonstrates the generalizability of NeuroMark templates and suggests the potential of new templates to boost accuracy in mental health research and advance our understanding of lifespan and cross-modal alterations.

Source-based morphometry reveals structural brain pattern abnormalities in 22q11.2 deletion syndrome

22q11.2 deletion syndrome (22q11DS) is the most frequently occurring microdeletion in humans. It is associated with a significant impact on brain structure, including prominent reductions in gray matter volume (GMV), and neuropsychiatric manifestations, including cognitive impairment and psychosis. It is unclear whether GMV alterations in 22q11DS occur according to distinct structural patterns. Then, 783 participants (470 with 22q11DS: 51% females, mean age [SD] 18.2 [9.2]; and 313 typically developing [TD] controls: 46% females, mean age 18.0 [8.6]) from 13 datasets were included in the present study. We segmented structural T1-weighted brain MRI scans and extracted GMV images, which were then utilized in a novel source-based morphometry (SBM) pipeline (SS-Detect) to generate structural brain patterns (SBPs) that capture co-varying GMV. We investigated the impact of the 22q11.2 deletion, deletion size, intelligence quotient, and psychosis on the SBPs. Seventeen GMV-SBPs were derived, which provided spatial patterns of GMV covariance associated with a quantitative metric (i.e., loading score) for analysis. Patterns of topographically widespread differences in GMV covariance, including the cerebellum, discriminated individuals with 22q11DS from healthy controls. The spatial extents of the SBPs that revealed disparities between individuals with 22q11DS and controls were consistent with the findings of the univariate voxel-based morphometry analysis. Larger deletion size was associated with significantly lower GMV in frontal and occipital SBPs; however, history of psychosis did not show a strong relationship with these covariance patterns. 22q11DS is associated with distinct structural abnormalities captured by topographical GMV covariance patterns that include the cerebellum. Findings indicate that structural anomalies in 22q11DS manifest in a nonrandom manner and in distinct covarying anatomical patterns, rather than a diffuse global process. These SBP abnormalities converge with previously reported cortical surface area abnormalities, suggesting disturbances of early neurodevelopment as the most likely underlying mechanism.

Decreased gray matter volume in regions associated with affective pain processing in unmedicated individuals with nonsuicidal self-injury

Nonsuicidal self-injury (NSSI) has been consistently associated with a reduced aversion to physical pain. Yet, little research has been done to investigate the brain structures related to pain in individuals with NSSI. This study examined gray matter volume patterns of pain processing regions in participants engaging in NSSI (n = 63) and age-, sex-, and handedness-matched healthy controls (n = 63). Voxel-based morphometry was performed to explore gray matter volume in regions of interest (ROIs) and partial correlation analyses were conducted to identify their associations with the frequency, versatility, duration, functions, and pain intensity of self-injury. As a result, significant volume decreases were found in the right anterior insula, bilateral secondary somatosensory cortex (SII), and left inferior frontal gyrus. Moreover, individuals with smaller anterior insula and SII volume showed a higher likelihood of endorsing affect-regulation and sensation-seeking functions of NSSI, as well as engaging in self-injury with a greater perceived intensity of pain. Our results provide the first empirical evidence that individuals with NSSI may exhibit distinct characteristics in brain regions associated with the affective component of pain processing. These neurobiological changes may be associated with their maladaptive response to noxious and painful NSSI experiences.

Adolescent neurodevelopment and psychopathology: The interplay between adversity exposure and genetic risk for accelerated brain ageing

In adulthood, stress exposure and genetic risk heighten psychological vulnerability by accelerating neurobiological senescence. To investigate whether molecular and brain network maturation processes play a similar role in adolescence, we analysed genetic, as well as longitudinal task neuroimaging (inhibitory control, incentive processing) and early life adversity (i.e., material deprivation, violence) data from the Adolescent Brain and Cognitive Development study (N = 980, age range: 9-13 years). Genetic risk was estimated separately for Major Depressive Disorder (MDD) and Alzheimer's Disease (AD), two pathologies linked to stress exposure and allegedly sharing a causal connection (MDD-to-AD). Adversity and genetic risk for MDD/AD jointly predicted functional network segregation patterns suggestive of accelerated (GABA-linked) visual/attentional, but delayed (dopamine [D2]/glutamate [GLU5R]-linked) somatomotor/association system development. A positive relationship between brain maturation and psychopathology emerged only among the less vulnerable adolescents, thereby implying that normatively maladaptive neurodevelopmental alterations could foster adjustment among the more exposed and genetically more stress susceptible youths. Transcriptomic analyses suggested that sensitivity to stress may underpin the joint neurodevelopmental effect of adversity and genetic risk for MDD/AD, in line with the proposed role of negative emotionality as a precursor to AD, likely to account for the alleged causal impact of MDD on dementia onset.

Sensory and Emotional Components in Tourist Memories of Wildlife Encounters: Intense, Detailed, and Long-Lasting Recollections of Individual Incidents

To quantify the role of senses and emotions in creating memorable tourism experiences, we need measurement frameworks that match how memories are created. This study examines that process through directed-content qualitative analysis of tourist encounters with wildlife. Data are derived from: interviews with 20 experienced wildlife tourism experts in 12 countries; 3000 social media posts on tourism enterprise and wildlife encounter websites; and participant observations and records of 168 memorable encounters involving >100 wildlife species, >850 tourists, and ~10,000 h in total, ranging over five decades. Across all data sources, senses and emotions differed between tourist interests and personalities, wildlife species and behaviours, and encounter circumstances. All senses were reported, with the most frequent being sight, followed by sound and smell, and, rarely, touch or taste. Descriptions were fine-grained and complex. The emotions reported were awe, joy, wonder, delight, thrill, amazement, envy, aww (cute-emotion), surprise, elation, satisfaction, interest, boredom, disappointment, sadness, embarrassment, concern, pity, distress, disgust, anxiety, shock, alarm, fear, and panic. Some experiences generated powerful recalls persisting for decades. Short-term, intense, and finely detailed senses and emotions defined experiences, created memories, and determined satisfaction, wellbeing, and subsequent outcomes. More accurate methods are needed to measure and characterise senses, emotions, and memories in tourism experience.