Evert Thiery

Ghent University | UGhent · Neuropsychology

Introduction: Sleep quality is closely linked with mental health. Two factors that influence sleep are coping style and locus of control, yet these have not been investigated in daily life. In this study, we examined associations between coping styles and sleep quality in daily life and the potential mediating effect of daily locus of control in a...

Adolescents and young adults are at high risk for experiencing loneliness, a well-established risk factor for mental health symptoms. Being physically active is known to reduce feelings of loneliness. We explored the association between physical activity and loneliness using the experience sampling method, allowing us to investigate moment-to-momen...

Reduced positive future thinking has been associated with suicidal ideation and behavior in adults, and appears to be exacerbated by negative affect. Yet, this has received little attention in youth. Prior research has also focused on longer-term future thinking, e.g., months and years, and relied on lab-based assessments. Using the experience samp...

Background: Adolescence is a period of both great social change, and of vulnerability to psychiatric distress. However, little is known about the associations between early psychopathology and social interactions at the fundamental level of daily life. To better understand the social correlates of subclinical psychopathology in adolescence, we ass...

Reduced positive future thinking has been associated with suicidal ideation and behaviour in adults, and appears to be exacerbated by negative affect. Yet, this has received little attention in youth. Prior research has also focussed on longer-term future thinking, e.g. months and years, and relied on lab-based assessments. Using the experience sam...

Parents are known to provide a lasting basis for their children's social development. Understanding parent-driven socialization is particularly relevant in adolescence, as an increasing social independence is developed. However, the relationship between key parenting styles of care and control and the microlevel expression of daily-life social inte...

Studies based on self-reported alcohol consumption and telomere length show inconsistent results. Therefore, we studied the association between gamma-glutamyl transferase (GGT), a widely used biomarker of alcohol intake, and telomere length. The possible health relevance in young adulthood was explored by investigating cardiometabolic risk factors....

Physical activity has positive effects on self-esteem and sense of belongingness and vice versa. The experience sampling method allows for a level of analysis of the within-subject temporal dynamics of these interactions. We hypothesized that physical activity would predict prospective increases of self-esteem and belongingness in the flow of daily...

Environmental and individual contextual factors profoundly influence how people regulate their emotions. The current article addresses the role of event intensity and psychopathology (an admixture of depression, anxiety, and psychoticism) on emotion regulation in response to naturally occurring events. For six days each evening, a youth sample (age...

Study Objectives We examined i) differences in overnight affective inertia (carry-over of evening affect to the next morning) for positive (PA) and negative affect (NA) between individuals with past, current, and no depression; ii) how sleep duration and quality influence overnight affective inertia in these groups, and iii) whether overnight affec...

Background Recent theories argue that an interplay between (i.e., network of) experiences, thoughts and affect in daily life may underlie the development of psychopathology. Objective To prospectively examine whether network dynamics of everyday affect states are associated with a future course of psychopathology in adolescents at an increased ris...

Background Telomere length (TL) is considered a biological marker of aging and may indicate age-related disease susceptibility. Adults and children show a fixed ranking and tracking of TL over time. However, the contribution of an individual's initial birth TL to their later life TL is unknown. We evaluated change and tracking of TL from birth to c...

Environmental and individual contextual factors profoundly influence how people regulate their emotions. The current article addresses the role of event intensity and psychopathology (an admixture of depression, anxiety, and psychoticism) on emotion regulation in response to naturally occurring events. For six days each evening, a youth sample (age...

Background Despite the increasing understanding of factors that might underlie psychiatric disorders, prospectively detecting shifts from a healthy towards a symptomatic state has remained unattainable. A complex systems perspective on psychopathology implies that such symptom shifts may be foreseen by generic indicators of instability, or early wa...

Background Exposure to green space has beneficial effects on several cognitive and behavioral aspects. However, to our knowledge, no study addressed intelligence as outcome. We investigated whether the level of urbanicity can modify the association of residential green space with intelligence and behavior in children. Methods and findings This stu...

Background: Alterations in the quantity and quality of social interactions play a role in early psychopathology, but not much is known about their involvement at the level of daily life. Aims: To better understand the social correlates of early psychopathology, the authors assessed associations between general psychopathology and the quantity and q...

Emotional complexity (EC) involves the ability to distinguish between distinct emotions (differentiation) and the experience of a large range of emotions (diversity). Lower EC has been related to psychopathology in cross-sectional studies. This study aimed to investigate (a) whether EC prospectively predicts psychopathology and (b) whether this eff...

Parenting experiences are hypothesized to provide a lasting basis for adaptive social functioning, but little is known about the manifestation of this effect in naturalistic, daily-life social interactions and experiences. To explore this question, adolescent and young adult twins and their siblings living with their parents (N = 628) completed the...

Introduction: There is growing evidence that mental disorders behave like complex dynamic systems. Complex dynamic systems theory states that a slower recovery from small perturbations indicates a loss of resilience of a system. This study is the first to test whether the speed of recovery of affect states from small daily life perturbations predi...

Objective: To test whether polygenic risk score for schizophrenia (PRS-S) interacts with childhood adversity and daily-life stressors to influence momentary mental state domains (negative affect, positive affect, and subtle psychosis expression) and stress-sensitivity measures. Methods: Data were retrieved from a general population twin cohort i...

Background: The temporal dynamics of cortisol may be altered in depression. Optimally studying these dynamics in daily life requires specific analytical methods. We used a continuous-time multilevel process model to study set point (rhythm-corrected mean), variability around this set point, and regulation strength (speed with which cortisol levels...

Meta-analyses suggest that clinical psychopathology is preceded by dimensional behavioral and cognitive phenotypes such as psychotic experiences, executive functioning, working memory and affective dysregulation that are determined by the interplay between genetic and nongenetic factors contributing to the severity of psychopathology. The liability...

Background: Developmental processes in the placenta and the fetal brain are shaped by the similar biological signals. Evidence accumulates that adaptive responses of the placenta may influence central nervous system development. We hypothesize that placental mtDNA content at birth is associated with intelligence in childhood. In addition, we inves...

Background: The earliest stages of the pluripotent psychopathology on the pathway to psychotic disorders is represented by emotional dysregulation and subtle psychosis expression, which can be measured using the Ecological Momentary Assessment (EMA). However, it is not clear to what degree common genetic and environmental risk factors for psychosis...

Purpose Whilst childhood trauma (CT) is a known risk factor across the spectrum of psychosis expression, little is known about possible interplay with genetic liability. Methods The TwinssCan Study collected data in general population twins, focussing on expression of psychosis at the level of subthreshold psychotic experiences. A multilevel mixed...

Background Emotional dysregulation and subtle psychosis expression mark the earliest manifestation of psychopathology. Furthermore, using Ecological Momentary Assessment (EMA), studies indicate that emotional and psychotic reactivity to daily-life stressors are associated with psychosis expression in individuals at varying clinical stages (e.g. ser...

Background: The study of networks of affective mental states that play a role in psychopathology may help model the influence of genetic and environmental risks. The aim of the present paper was to examine networks of affective mental states (AMS: ‘cheerful’, ‘insecure’, ‘relaxed’, ‘anxious’, ‘irritated’ and ‘down’) over time, stratified by genetic...

Adolescents and young adults are highly focused on peer evaluation, but little is known about sources of their differential sensitivity. We examined to what extent sensitivity to peer evaluation is influenced by interacting environmental and genetic factors. A sample of 354 healthy adolescent twin pairs (n = 708) took part in a structured, laborato...

Background: Converging evidence supports childhood trauma as possible causal risk for psychosis and related psychopathology. However, studies have shown that baseline psychotic symptoms may actually increase risk for subsequent victimization, suggesting that exposure to CT is not random but may result from pre-existing vulnerability. Therefore, st...

Background Studies using the event sampling method (ESM), a structured diary technique measuring subjective experiences and emotional fluctuations in daily life, have consistently shown that individuals reporting psychotic experiences display a heightened emotional reactivity to minor stressors—a neuropsychological mechanism that likely contributes...

Childhood trauma exposure has been associated with a clinically relevant mixed phenotype of psychopathology composed of depressive, anxiety, and psychosis symptoms, across healthy and clinical samples. Altered stress-reactivity after exposure to childhood trauma may be a plausible underlying mechanism explaining this association. In a general popul...

Background Telomere attrition is extremely rapid during the first years of life, while lifestyle during adulthood exerts a minor impact. This suggests that early life is an important period in the determination of telomere length. We investigated the importance of the early-life environment on both telomere tracking and adult telomere length. Meth...

Background: The network analysis of intensive time series data collected using the Experience Sampling Method (ESM) may provide vital information in gaining insight into the link between emotion regulation and vulnerability to psychopathology. The aim of this study was to apply the network approach to investigate whether genetic liability (GL) to p...

Background An association between white noise speech illusion and psychotic symptoms has been reported in patients and their relatives. This supports the theory that bottom-up and top-down perceptual processes are involved in the mechanisms underlying perceptual abnormalities. However, findings in nonclinical populations have been conflicting. Obj...

Supporting material: Dataset and labels of education levels. (XLS)

Purpose: The aim of the current study was to replicate findings in adults indicating that higher sensitivity to stressful events is predictive of both onset and persistence of psychopathological symptoms in a sample of adolescents and young adults. In addition, we tested the hypothesis that sensitivity to mild stressors in particular is predictive...

Objective: Focusing on temporal associations between momentary (or state) loneliness, appraisal of social company, and being alone in daily life may help elucidate mechanisms that contribute to the development of prolonged (or trait) loneliness and major depressive disorder (MDD). We aim to examine if (a) a self-reinforcing loop between loneliness...

Introduction: Negative social evaluation is associated with psychopathology. Given the frequency of evaluation through increasingly prevalent virtual social networks, increased understanding of the effects of this social evaluation is urgently required. Methods: A new digital social peer evaluation experiment (digi-SPEE) was developed to mimic e...

Many of the decisions and actions in everyday life result from implicit learning processes. Important to psychopathology are, for example, implicit reward-seeking and punishment-avoidant learning processes. It is known that when specific actions get associated with a rewarding experience, such as positive emotions, that this will increase the likel...

VNS therapy was delivered to patients for the first time in 1988. After 25 years, insight in the antiepileptic and antidepressant mechanism of action of VNS has grown steadily. The effects on cognition and especially memory, remain controversial. This review provides an elaborate overview of studies addressing cognition and describes potential unde...

A network approach to mental disorder may prove valuable to complement current diagnostic practice and may help us to better understand both phenomenology and development of psychopathology. These studies represent first explorations of the network approach to mental state connectivity in the field of psychopathology.

Intrauterine factors important for cognitive development, such as birth weight, chorionicity and umbilical cord characteristics were investigated. A total of 663 twin pairs completed the Wechsler Intelligence Scale for Children-Revised and scores were available for Performance, Verbal and Total Intelligence Quotient (IQ). The intrauterine factors e...

Positive affect (PA) is closely linked to prevention of, and recovery from, depression. Previous studies have investigated PA reactivity to pleasant situations with respect to its protective properties in relation to mood disorder. The purpose of this study was to examine, and replicate, whether moment-to-moment transfer of PA in daily life (PA per...

Multiple lines of evidence suggest that fatty acids (FA) play an important role in cognitive function. However, little is known about the functional genetic pathways involved in cognition. The main goals of this study were to replicate previously reported interaction effects between breast feeding (BF) and FA desaturase (FADS) genetic variation on...

Linkage disequilibrium (LD) in the FADS gene cluster. LD block representation of genes and genetic variants present in FADS cluster region using Haploview [53,54] (HapMap CEU, NCBI36) and UCSC browser (NCBI36/hg18). Genes are represented in blue, blue bars are exons, blue arrows represent transcription direction. Genetic variants in black were repo...

A visual representation of the FADS1 and FADS2 5′ UTR shared region of mouse and human genomic alignments (VISTA comparative tool). The alignment figure shows the human-mouse conservation curves, where dark and light blue boxes represent exons and UTRs respectively. Gene name appears above the track, the arrow points in the direction of the gene. T...

Amino acid sequence alignment of human and mouse FADS1, FADS2 and FADS3. Human amino acid reference sequences FADS1: NP_037534.3, FADS2: NP_004256.1 and FADS3: NP_068373.1. Mouse amino acid reference sequences FADS1: NP_666206.1, FADS2: NP_062673.1; FADS3: NP_068690.3. Identical amino acids are marked by letter code, “+” symbol are “homologous” sub...

Objective Altered social reward functioning is associated with psychosis irrespective of stage and severity. Examining the role of social reward functioning prospectively in relation to psychotic experiences before these become persistent and potentially disabling can aid in elucidating social mechanisms that induce shifts toward more severe psycho...

Background: Poor sleep is a risk factor for depression, but little is known about the underlying mechanisms. Aims: Disentangling potential mechanisms by which sleep may be related to depression by zooming down to the 'micro-level' of within-person daily life patterns of subjective sleep and affect using the experience sampling method (ESM). Met...

Subclinical psychotic experiences at the level of the general population are common, forming an extended psychosis phenotype with clinical psychosis. Persistence of subclinical experiences is associated with transition to later mental disorder. Increased daily life stress reactivity is considered an endophenotype for psychotic disorders. We examine...

Mental disorders may be reducible to sets of symptoms, connected through systems of causal relations. A clinical staging model predicts that in earlier stages of illness, symptom expression is both non-specific and diffuse. With illness progression, more specific syndromes emerge. This paper addressed the hypothesis that connection strength and con...

Background: FK506 binding protein 5 (FKBP5) has repeatedly been shown to be a critical determinant of post-traumatic stress disorder (PTSD) and depression following childhood trauma. Aims: To examine the role of FKBP5-trauma interactions in the partly stress-related psychosis phenotype. Method: In 401 general population twins, four functional...

Psychotic disorders are thought to represent altered neural function. However, research has failed to map diagnostic categories to alterations in neural networks. It is proposed that the basic unit of psychotic psychopathology is the moment-to-moment expression of subtle anomalous experiences of subclinical psychosis, and particularly its tendency...

Evidence suggests that affect plays a role in the development of psychosis but the underlying mechanism requires further investigation. This study examines the moment-to-moment dynamics between negative affect (NA) and paranoia prospectively in daily life. A female general population sample (n = 515) participated in an experience sampling study. Ti...

In this study, we present long-term results from patients with medial temporal lobe (MTL) epilepsy treated with deep brain stimulation (DBS). Since 2001, 11 patients (8M) with refractory MTL epilepsy underwent MTL DBS. When unilateral DBS failed to decrease seizures by > 90%, a switch to bilateral MTL DBS was proposed. After a mean follow-up of 8.5...

The East Flanders Prospective Twin Survey (EFPTS) is a prospective, population-based registry of multiple births in the province of East-Flanders, Belgium. EFPTS has several unique features: it is population-based and prospective, with the possibility of long-term follow-up; the twins (and higher order multiple births) are recruited at birth; basic...

Momentary positive affect (PA) and reward experience may underlie subjective wellbeing, and index mental health resilience. This study examines their underlying sources of variation and the covariation with stress-sensitivity. The experience sampling method was used to collect multiple appraisals of mood and daily life events in 520 female twins. S...

Objective: The daily life, affective phenotypes of momentary negative affect (NA), positive affect (PA) variability and NA variability are associated with future depressive symptomatology. This study investigates the extent to which genetic and environmental factors contribute to the inter-individual differences in these daily life, affective phen...

Novel study designs using within-subject methodology and frequent and prospective measurements are required to unravel direction of causality and dynamic processes of behavior over time. The current study examined the effects of physical activity on affective state. A primary and within-study replication sample was derived from twin pairs. Female t...