This dissertation focused on the neural and behavioral mechanisms underlying adolescent learning and mental health in the context of peers and friends. The neuroimaging findings revealed that... Show moreThis dissertation focused on the neural and behavioral mechanisms underlying adolescent learning and mental health in the context of peers and friends. The neuroimaging findings revealed that reward processing for self and peers rely on common reward-related brain regions, whereas a social brain region (TPJ) showed social specificity to observed outcomes for unfamiliar peers compared to friends. Moreover, typically developing adolescents and adolescents with ADHD show neural sensitivity in reward and salience brain regions towards rewards for themselves, friends and peers compared to losses. There were no group differences in neural processing of (vicarious) outcomes between adolescents with and without ADHD, yet a symptom-level approach showed more neural sensitivity for own compared to friends’ losses in individuals with more inattention symptoms. The behavioral findings indicated that adolescents’ learning performance benefitted from observing the choices and outcomes of peers irrespective of the relationship with this peer. The results did not show effects of friendship (quality) and social status on observational and academic learning, but there was a protective effect of friendship quality on internalizing problems. Taken together, these findings highlight adolescence as a period of observational learning opportunities from different types of peers. Adolescence can also serve as a window of opportunity to improve mental health by fostering high-quality friendships. Show less
Fischer, K.; Tieskens, J.M.; Luijten, M.A.J.; Zijlmans, J.; Oers, H.A. van; Groot, R. de; ... ; Popma, A. 2022
The aim of the study was to assess internalizing problems before and during the pandemic with data from Dutch consortium Child and adolescent mental health and wellbeing in times of the COVID-19... Show moreThe aim of the study was to assess internalizing problems before and during the pandemic with data from Dutch consortium Child and adolescent mental health and wellbeing in times of the COVID-19 pandemic, consisting of two Dutch general population samples (GS) and two clinical samples (CS) referred to youth/psychiatric care. Measures of internalizing problems were obtained from ongoing data collections pre-pandemic (N-GS = 35,357; N-CS = 4487) and twice during the pandemic, in Apr-May 2020 (N-GS = 3938; clinical: N-CS = 1008) and in Nov-Dec 2020 (N-GS = 1489; N-CS = 1536), in children and adolescents (8-18 years) with parent (Brief Problem Monitor) and/or child reports (Patient-Reported Outcomes Measurement Information System (R)). Results show that, in the general population, internalizing problems were higher during the first peak of the pandemic compared to pre-pandemic based on both child and parent reports. Yet, over the course of the pandemic, on both child and parent reports, similar or lower levels of internalizing problems were observed. Children in the clinical population reported more internalizing symptoms over the course of the pandemic while parents did not report differences in internalizing symptoms from pre-pandemic to the first peak of the pandemic nor over the course of the pandemic. Overall, the findings indicate that children and adolescents of both the general and clinical population were affected negatively by the pandemic in terms of their internalizing problems. Attention is therefore warranted to investigate long-term effects and to monitor if internalizing problems return to pre-pandemic levels or if they remain elevated post-pandemic. Show less
The current thesis focuses on the longitudinal development of early-adopted children in the 1887/29874 Leiden Longitudinal Adoption Study (LLAS). In the LLAS, adopted children were followed from... Show moreThe current thesis focuses on the longitudinal development of early-adopted children in the 1887/29874 Leiden Longitudinal Adoption Study (LLAS). In the LLAS, adopted children were followed from infancy until young adulthood. In Chapter 1 we discuss the role of sensitive parenting and the precursors and developmental outcomes of attachment security. In the empirical study in Chapter 2 we report on the concurrent as well as longitudinal relations between maternal sensitivity, child temperament, and externalizing behavior problems. In the second empirical study in Chapter 3, we follow this line of enquiry and investigate concurrent and longitudinal relations between maternal sensitivity, child temperament and internalizing behavior problems. Chapter 4 reports on the final empirical study of the thesis, and focuses on the associations between maternal sensitivity and attachment in infancy and the diurnal cortisol curve in young adulthood. Our empirical studies show that maternal sensitivity in infancy and middle childhood indirectly predicts fewer internalizing behavior problems in adopted adolescents, and that maternal sensitivity in adolescence predicts less concurrent delinquent behavior. Attachment experiences in early life do not predict the adoptees' diurnal cortisol curve in later life. In Chapter 5 we discuss these results and some methodological issues more thoroughly. Show less
The goal of this dissertation was to enhance our understanding about internalizing problems and peer relations in DHH youth (aged around 11 years). This was done along principles of the... Show moreThe goal of this dissertation was to enhance our understanding about internalizing problems and peer relations in DHH youth (aged around 11 years). This was done along principles of the developmental psychopathology framework in which DHH children were compared to their hearing counterparts and in which multiple (underlying) social-emotional factors were examined. Results showed that DHH youth reported equal levels of somatic complaints, but more depressive symptoms, lower friendship quality and some forms of victimization more than their hearing peers. Throughout the dissertation a recurring DHH-related characteristic causing variability within the DHH sample was type of education; DHH children in special education reported poorer outcomes than their DHH peers in mainstream education. Concerning the underlying factors, a key finding was that emotional functioning underlies the development of internalizing problems and peer relations in both DHH and hearing youth, while the influence of social factors caused a discrepancy between the two groups. For example, poor social understanding is related to depressive symptoms in DHH youth, while this relation is absent in the hearing sample. Peer relations and social understanding should receive focal attention in practice and future research with DHH youth. Show less
