Parental Age in Relation to Offspring's Neurodevelopment.

Objective: Advanced parenthood increases the risk of severe neurodevelopmental disorders like autism, Down syndrome and schizophrenia. Does advanced parenthood also negatively impact offspring's general neurodevelopment?Method: We analyzed child-, father-, mother- and teacher-rated attention-problems (N = 38,024), and standardized measures of intelligence (N = 10,273) and educational achievement (N = 17,522) of children from four Dutch population-based cohorts. The mean age over cohorts varied from 9.73-13.03. Most participants were of Dutch origin, ranging from 58.7%-96.7% over cohorts. We analyzed 50% of the data to generate hypotheses and the other 50% to evaluate support for these hypotheses. We aggregated the results over cohorts with Bayesian research synthesis.Results: We mostly found negative linear relations between parental age and attention-problems, meaning that offspring of younger parents tended to have more attention problems. Maternal age was positively and linearly related to offspring's IQ and educational achievement. Paternal age showed an attenuating positive relation with educational achievement and an inverted U-shape relation with IQ, with offspring of younger and older fathers at a disadvantage. Only the associations with maternal age remained after including SES. The inclusion of child gender in the model did not affect the relation between parental age and the study outcomes.Conclusions: Effects were small but significant, with better outcomes for children born to older parents. Older parents tended to be of higher SES. Indeed, the positive relation between parental age and offspring neurodevelopmental outcomes was partly confounded by SES.

The Role of Stressful Parenting and Mineralocorticoid Receptor Haplotypes on Social Development During Adolescence and Young Adulthood.

The development of social behavior could be affected by stressful parenting. The mineralocorticoid receptor, one of the two main receptors for the stress hormone cortisol, plays a vital role in adequate responses to stress. Therefore, the effects of stressful parenting on social development (i.e., empathic concern, perspective taking and prosocial behavior) may be moderated by functional genetic variation in mineralocorticoid receptor haplotypes (a combination of alleles). A group of 343 adolescents (44.3% females) was followed from the age of 13 until 24 years. Growth curve analyses showed lower levels of prosocial behaviors and a slower increase in empathic concern and perspective taking in adolescents who reported more stressful parenting. In contrast, relatively higher levels of prosocial behavior, empathic concern and perspective taking were present in combination with stress resilient mineralocorticoid receptor haplotypes. Despite sex differences in social development with earlier social development for girls, no consistent sex differences were found with regard to mineralocorticoid receptor haplotypes. The current study showed that genetic variation in mineralocorticoid receptor impacts the social development during adolescence and young adulthood.

An experimental investigation of the influence of deviant peers on own deviancy: A replication study.

OBJECTIVES: This study is a replication of a study examining the causal impact of a brief exposure to deviant peers on own deviant behavior, i.e., Paternoster et al. (Journal of Research in Crime and Delinquency, 50:476-503, 2013). This study retested this design using different monetary incentives and a female deviant peer. METHODS: A total of 69 university students (61% female) from the Netherlands participated in this laboratory-based study (Mage = 20.64; SD = 2.00) under the façade of a study on individual differences predicting memory recall. Participants could earn up to 10 euros. All participants had the opportunity to cheat to illegitimately earn more money (deviancy). Participants in the experimental condition were exposed to a deviant peer who verbalized her intention to cheat, justified this behavior, and then visibly cheated on the memory recall task. RESULTS: Although participants in both conditions engaged in some deviancy, the brief exposure to a deviant peer significantly increased the amount of deviancy compared to participants who were not exposed to a deviant peer. These results were consistent after controlling for different demographic and theoretical control variables that predict deviancy. CONCLUSIONS: Although not identical in magnitude, our results echo those found by Paternoster et al. (2013): Even a brief exposure to a previously unknown deviant peer increases the amount of deviant behavior in young adults. Future research should examine factors predicting the susceptibility to (different types and thresholds of) deviant peer influence.

Induction of gonadal maturation at different temperatures in burbot Lota lota.

A rearing experiment was conducted to test whether temperature protocols that differed from a simulation of natural conditions might induce maturation after isothermal grow-out in burbot Lota lota. Lota lota were acclimated to two different temperature regimes: low temperature (LT), close to natural temperature at 4·0° C and elevated, high temperature (HT) at 8·5° C over 40 and 27 days respectively, with all fish then wintered for 47 days. Every second fish was treated with a gonadotropin-releasing hormone analogue. Maturational competence of oocytes was assessed with a germinal vesicle breakdown assay using a novel staining strategy. In both treatments, puberty and maturational progress occurred, characterised by an elevated gonado-somatic index and advanced gonadal stages (histological analysis). Progress of gonadal maturation was reflected by elevated plasma concentrations of testosterone and 11-ketosterone in males and 17ß-oestradiol in females. Ovulation was not observed. Sperm could be activated equally across treatments. In general, LT was more effective than HT treatment, indicated by advanced gonadal stages, higher numbers of oocytes undergoing germinal vesicle breakdown in vitro and elevated sex steroid levels. Hormone treatment could improve effectiveness at HT. In conclusion, less drastic temperature regimes as previously reported in combination with hormone treatments seem sufficient to induce maturation in L. lota after isothermal grow-out.

Discrepancies Between Perceptions of the Parent-Adolescent Relationship and Early Adolescent Depressive Symptoms: An Illustration of Polynomial Regression Analysis.

Adolescence is a critical period for the development of depressive symptoms. Lower quality of the parent-adolescent relationship has been consistently associated with higher adolescent depressive symptoms, but discrepancies in perceptions of parents and adolescents regarding the quality of their relationship may be particularly important to consider. In the present study, we therefore examined how discrepancies in parents' and adolescents' perceptions of the parent-adolescent relationship were associated with early adolescent depressive symptoms, both concurrently and longitudinally over a 1-year period. Our sample consisted of 497 Dutch adolescents (57 % boys, M age = 13.03 years), residing in the western and central regions of the Netherlands, and their mothers and fathers, who all completed several questionnaires on two occasions with a 1-year interval. Adolescents reported on depressive symptoms and all informants reported on levels of negative interaction in the parent-adolescent relationship. Results from polynomial regression analyses including interaction terms between informants' perceptions, which have recently been proposed as more valid tests of hypotheses involving informant discrepancies than difference scores, suggested the highest adolescent depressive symptoms when both the mother and the adolescent reported high negative interaction, and when the adolescent reported high but the father reported low negative interaction. This pattern of findings underscores the need for a more sophisticated methodology such as polynomial regression analysis including tests of moderation, rather than the use of difference scores, which can adequately address both congruence and discrepancies in perceptions of adolescents and mothers/fathers of the parent-adolescent relationship in detail. Such an analysis can contribute to a more comprehensive understanding of risk factors for early adolescent depressive symptoms.

The STRESS-NL database: A resource for human acute stress studies across the Netherlands.

Stress initiates a cascade of (neuro)biological, physiological, and behavioral changes, allowing us to respond to a challenging environment. The human response to acute stress can be studied in detail in controlled settings, usually in a laboratory environment. To this end, many studies employ acute stress paradigms to probe stress-related outcomes in healthy and patient populations. Though valuable, these studies in themselves often have relatively limited sample sizes. We established a data-sharing and collaborative interdisciplinary initiative, the STRESS-NL database, which combines (neuro)biological, physiological, and behavioral data across many acute stress studies in order to accelerate our understanding of the human acute stress response in health and disease (www.stressdatabase.eu). Researchers in the stress field from 12 Dutch research groups of 6 Dutch universities created a database to achieve an accurate inventory of (neuro)biological, physiological, and behavioral data from laboratory-based human studies that used acute stress tests. Currently, the STRESS-NL database consists of information on 5529 individual participants (2281 females and 3348 males, age range 6-99 years, mean age 27.7 ±â€¯16 years) stemming from 57 experiments described in 42 independent studies. Studies often did not use the same stress paradigm; outcomes were different and measured at different time points. All studies currently included in the database assessed cortisol levels before, during and after experimental stress, but cortisol measurement will not be a strict requirement for future study inclusion. Here, we report on the creation of the STRESS-NL database and infrastructure to illustrate the potential of accumulating and combining existing data to allow meta-analytical, proof-of-principle analyses. The STRESS-NL database creates a framework that enables human stress research to take new avenues in explorative and hypothesis-driven data analyses with high statistical power. Future steps could be to incorporate new studies beyond the borders of the Netherlands; or build similar databases for experimental stress studies in rodents. In our view, there are major scientific benefits in initiating and maintaining such international efforts.

Robust longitudinal multi-cohort results: The development of self-control during adolescence.

Longitudinal data from multiple cohorts may be analyzed by Bayesian research synthesis. Here, we illustrate this approach by investigating the development of self-control between age 13 and 19 and the role of sex therein in a multi-cohort, longitudinal design. Three Dutch cohorts supplied data: the Netherlands Twin Register (NTR; N = 21,079), Research on Adolescent Development and Relationships-Young (RADAR-Y; N = 497), and Tracking Adolescents' Individual Lives Survey (TRAILS; N = 2229). Self-control was assessed by one measure in NTR and RADAR-Y, and three measures in TRAILS. In each cohort, we evaluated evidence for competing informative hypotheses regarding the development of self-control. Subsequently, we aggregated this evidence over cohorts and measures to arrive at a robust conclusion that was supported by all cohorts and measures. We found robust evidence for the hypothesis that on average self-control increases during adolescence (i.e., maturation) and that individuals with lower initial self-control often experience a steeper increase in self-control (i.e., a pattern of recovery). From self-report, boys have higher initial self-control levels at age 13 than girls, whereas parents report higher self-control for girls.

[Developmental trajectories of anxiety disorder symptoms in adolescents: a five-year prospective community study]. / Ontwikkelingstrajecten van angstsymptomen: een vijfjarig prospectief onderzoek onder adolescenten uit de algemene populatie.

BACKGROUND: The relatively recent adoption of modern statistical analysis methods, such as latent growth modelling (lgm), makes it possible to study differences in the individual trajectories of development over time. AIM: To examine prospectively the developmental trajectories of anxiety disorder symptoms in a large sample of adolescents (N = 1,318) from the general population over a period of five years. METHOD: The adolescents were divided into two cohorts: early adolescents (average age 12 at the first measurement) and middle adolescents (average age 16 at the first measurement). Age and gender differences in the developmental trajectories of adolescent anxiety disorder symptoms over time were examined by means of lgm. results Over the course of five years there was a slight decrease in panic disorder, school anxiety and separation anxiety disorder symptoms for all adolescents, with the exception of social phobia symptoms, which remained fairly stable over time. Adolescent girls showed a slight increase in generalised anxiety disorder symptoms over time, whereas these symptoms decreased among adolescent boys. CONCLUSION: The use of individual trajectory-based analyses, enabled us to study advance our understanding of age and gender differences in the development of adolescent anxiety symptoms.

The role of stress reactivity in the long-term persistence of adolescent social anxiety symptoms.

Social Anxiety Disorder (SAD) symptoms demonstrate a marked persistence over time, but little is known empirically about short-term processes that may account for this long-term persistence. In this study, we examined how self-reported and physiological stress reactivity were associated with persistence of SAD symptoms from early to late adolescence. A community sample of 327 adolescents (56% boys, Mage=13.01 at T1) reported their SAD symptoms for 6 successive years and participated in a public speaking task, during which self-reported (i.e., perceived nervousness and heart rate) and physiological (i.e., cortisol and heart rate) measures of stress were taken. Overall, our results point to a developmental process in which adolescents with a developmental history of higher SAD symptoms show both heightened perceived stress reactivity and heart rate reactivity, which, in turn, predict higher SAD symptoms into late adolescence.

Childhood Predictors and Adult Life Success of Adolescent Delinquency Abstainers.

While much is known about adolescent delinquency, considerably less attention has been given to adolescent delinquency abstention. Understanding how or why some adolescents manage to abstain from delinquency during adolescence is informative for understanding and preventing adolescent (minor) delinquency. Using data from the Cambridge Study in Delinquent Development (N = 411 males) to compare abstainers, self-report delinquents and convicted delinquents we found five childhood factors (ages 8-10) that predicted adolescent abstention (ages 10-18). First, we find that adolescent abstainers possess characteristics opposite to those of convicted delinquents (namely, abstainers are high on honesty, conformity and family income). However, we also found that abstainers also share some childhood characteristics with convicted delinquents (namely, low popularity and low school achievement). A latent class analysis indicated that the mixed factors predicting abstention can be accounted for by two groups of abstainers: an adaptive group characterized by high honesty, and a maladaptive group characterized by low popularity and low school achievement. Further, validation of these two types of abstainers using data collected at age 48 suggested that adaptive abstainers outperform all other adolescents in general life success, whereas maladaptive abstainers only fare better than delinquent adolescents in terms of lower substance use and delinquency later in life.

Genome-wide association study of lifetime cannabis use based on a large meta-analytic sample of 32 330 subjects from the International Cannabis Consortium.

Cannabis is the most widely produced and consumed illicit psychoactive substance worldwide. Occasional cannabis use can progress to frequent use, abuse and dependence with all known adverse physical, psychological and social consequences. Individual differences in cannabis initiation are heritable (40-48%). The International Cannabis Consortium was established with the aim to identify genetic risk variants of cannabis use. We conducted a meta-analysis of genome-wide association data of 13 cohorts (N=32 330) and four replication samples (N=5627). In addition, we performed a gene-based test of association, estimated single-nucleotide polymorphism (SNP)-based heritability and explored the genetic correlation between lifetime cannabis use and cigarette use using LD score regression. No individual SNPs reached genome-wide significance. Nonetheless, gene-based tests identified four genes significantly associated with lifetime cannabis use: NCAM1, CADM2, SCOC and KCNT2. Previous studies reported associations of NCAM1 with cigarette smoking and other substance use, and those of CADM2 with body mass index, processing speed and autism disorders, which are phenotypes previously reported to be associated with cannabis use. Furthermore, we showed that, combined across the genome, all common SNPs explained 13-20% (P<0.001) of the liability of lifetime cannabis use. Finally, there was a strong genetic correlation (rg=0.83; P=1.85 × 10(-8)) between lifetime cannabis use and lifetime cigarette smoking implying that the SNP effect sizes of the two traits are highly correlated. This is the largest meta-analysis of cannabis GWA studies to date, revealing important new insights into the genetic pathways of lifetime cannabis use. Future functional studies should explore the impact of the identified genes on the biological mechanisms of cannabis use.

Implicit alcohol-relaxation associations in frequently drinking adolescents with high levels of neuroticism.

INTRODUCTION: Most individuals start drinking during adolescence, a period in which automatically activated or implicit cognitive processes play an important role in drinking behavior. The aim of this study was to examine personality-related antecedents of implicit associations between alcohol and positive or negative reinforcement motives in adolescents. It was hypothesized that frequent alcohol consumption in combination with specific personality traits (neuroticism for negative reinforcement and extraversion for positive reinforcement) could predict specific implicit alcohol-relaxation and arousal associations. METHODS: Participants completed a brief Big Five Questionnaire and alcohol use questions at T1. Approximately eight months later (T2), two Brief Implicit Association Tests were completed to assess alcohol-relaxation (negative reinforcement, n=222) and alcohol-arousal (positive reinforcement, n=248) associations. RESULTS: Results indicated that frequently drinking adolescents who scored high on neuroticism had the strongest alcohol-relaxation associations eight months later. No significant predictors were observed for alcohol-arousal associations. CONCLUSIONS: The current study identified precursors of strong implicit alcohol-relaxation associations (i.e., high levels of neuroticism in combination with frequent alcohol consumption) which can inform future prevention and intervention studies.

How do vocational and relationship stressors and identity formation affect adolescent mental health?

PURPOSE: This article examines the effects of stressors in both the vocational and relationship career of youngsters in the formation of their identity; the effects of identity formation on adolescent mental health; the influence of career stressors on mental health, directly or via identity, and differences in these effects on boys and girls. METHODS: Data were used from the Dutch national panel study, Utrecht Study of Adolescent Development, a study of developmental processes as they occur in the life course of young people during the 1990s. Using LISREL, we tested hypotheses on two waves of a sample of 1222 respondents between 15 and 24 years of age in Wave 1 (1991). RESULTS: The correlation between relationship stressors and relationship identity can be neglected, while vocational stressors lead to a less achieved vocational identity, particularly in boys. Occupational and relationship identity have similar effects on mental health (i.e., the more achieved the identity, the better the person's mental health). Vocational and especially relationship stressors lead to poorer mental health, but did not affect the mental health of boys and girls differently. The same goes for the influence of relationship and vocational identity formation on mental health. CONCLUSIONS: Career stressors, especially stressors in the relationship domain, appear to have significant long-term effects on adolescent mental health. Vocational and relationship identity formation are also significant predictors for adolescent mental health.

Occupational identity development, school performance, and social support in adolescence: findings of a Dutch study.

Three hundred adolescents completed a Dutch version of the Dellas Identity Status Inventory-Occupation (DISI-O). Reliability of the five subscales ranged from "sufficient" to "very good," and the four identity status classifications accommodated about 90% of the respondents. As expected, achievement and social support by friends in the educational setting stimulated development of occupational identity.

Identity development, parental and peer support in adolescence: results of a national Dutch survey.

The aims of this study were to examine the development and structure of identity throughout adolescence, and the influence of parents and peers on identity development. A representative sample of Dutch adolescents, aged 12 to 14, completed the Utrecht-Groningen Identity Development Scale (U-GIDS). This instrument encompasses separate scales for commitment in exploration for relational, school, and occupational identity. The results show that relational identity becomes consistently stronger as adolescents grow older. Less consistent developmental trends were found for school identity, and no developmental trends for occupational identity. A different identity structure was found in different groups of adolescents. For girls the relational identity is much more important than school or occupational identity. The same difference was found in adolescents aged 21 to 24 vs. their younger peers. Identity development is mostly influenced by peers, with parents having only an additive positive influence.

Commitment and exploration as mechanisms of identity formation.

We report a two-wave longitudinal study of 1,571 Dutch adolescents concerning the role of commitment and exploration in identity development. We used the Utrecht-Groningen Identity Development Scale to measure commitment and exploration in the domains of relational and societal identity. Our results can be summarized in three points. (1) Commitment and exploration are related processes in the development of identity. Adolescents with strong commitments also frequently explore them, and adolescents with low exploration in general have weak commitments. (2) The longitudinal stability of commitment and exploration has a medium effect size. For relational identity the stability of commitment is greater than that of exploration, but this is not the case for societal identity. The explanation we give for the lack of this difference in stability between commitment and exploration in societal identity is that the formative period for societal identity comes primarily at the end of adolescence. In that connection, we conclude that for present-day Dutch adolescents the formation of relational identity probably precedes that of societal identity. (3) In neither identity domain is commitment predictive of exploration three years later, nor is the reverse the case. We conclude that no long-term developmental sequentiality of commitment and exploration was found, but the results do not rule out the possibility of short-term developmental sequentiality.

A longitudinal biosocial study of cortisol and peer influence on the development of adolescent antisocial behavior.

It is increasingly recognized that in order to understand the complex phenomenon of antisocial behavior, interrelations between biological and social risk factors should be taken into account. In the current study, this biosocial approach was applied to examine the mediating role of deviant peers in longitudinal associations linking the level of hypothalamic-pituitary-adrenal (HPA) axis activity to aggression and rule-breaking. Participants were 425 boys and girls from the general population, who were assessed yearly at ages 15, 16, and 17. As a measure of HPA axis activity, cortisol was assessed at awakening, 30, and 60 min later (the cortisol awakening response, CAR). Participants, as well as their best friend, reported on their own aggressive and rule-breaking behavior, thereby allowing to assess bidirectional influences within friendships. Aggression was only predicted by a decreased cortisol level at awakening, and not by aggressive behavior of their friend. Decreased levels of cortisol at awakening predicted adolescents' rule-breaking, which subsequently predicted increased rule-breaking of their best friend. The latter was only found for adolescents who changed friends, as compared to adolescents with the same friend in every year. Gender differences were not found. These findings suggest that interrelations between biological and social risk factors are different for the development of aggression versus rule-breaking. Furthermore, decreased levels of HPA axis activity may represent a susceptibility to selecting deviant peers.

Developmental trajectories of perceived friendship intimacy, constructive problem solving, and depression from early to late adolescence.

This study examined friendship types in developmental trajectories of perceived closeness and balanced relatedness. In addition, differences between friendship types in the development of constructive problem solving and depression were examined. Questionnaire data of five annual waves were used from two adolescent cohorts (cohort 1: M = 12.41 years; cohort 2: M = 16.37 years). Growth Mixture Modeling revealed two developmental trajectories in cognitive representations of perceived friendship intimacy: interdependent and disengaged friendships. Adolescents in interdependent friendships were characterized by high perceived closeness and balanced relatedness across adolescence. Furthermore, adolescents in disengaged friendships had lower levels of and smaller increases in constructive problem solving. Girls in disengaged friendships showed smaller increases in balanced relatedness and higher levels of depression than boys in disengaged friendships and adolescents in interdependent friendships.

Sublethal copper exposure induces respiratory stress in common and gibel carp but not in rainbow trout.

Rainbow trout, common carp, and gibel carp were exposed to sublethal Cu levels (1.0 or 1.7 microM) for 1 week. In rainbow trout, arterial oxygen tension (P(aO(2))) remained normal and there was no indication of anaerobic metabolism. P(aO(2)) was considerably lower in common and gibel carp and Cu exposure decreased this further. The decrease was transient for common carp but persistent in gibel carp and coincided with an elevation in arterial carbon dioxide tension (P(aCO(2))) indicating that all gas exchange was compromised in both cyprinid species. The disturbed gas exchange resulted in acidosis, which was respiratory and metabolic for common carp but mainly respiratory for gibel carp. Gibel carp produced ethanol as end product of their alternative anaerobic pathway. The hypothesis that hypertrophy and hyperplasia, resulting in increased diffusion distances, are reducing P(aO(2)) appeared invalid. Hypoventilation seems a more likely cause. Ionoregulatory parameters responded more uniform among species. Fast and pronounced decreases in plasma sodium and chloride developed for all three species, independent of the observed gill damage. Rainbow trout lost 20% of their plasma Na in the first 3 days, while common and gibel carp had only lost 13 and 16% respectively at that time. This difference might be crucial when challenged with Cu exposure and allow a fish to survive the first shock phase and supports it the hypothesis that sodium turnover is a key factor in predicting Cu toxicity.

The effects of work and relational mental incongruity on identity formation and well-being.

By combining concepts of Tazelaar's mental incongruity theory (1983) and Marcia's identity model (1993) we tried to uncover some theoretical mechanisms that may underlie progressive developmental trends in identity status. Mental incongruity is what people experience when there is a discrepancy between how they think a situation should be (the standard) and how they experience the actual situation or their own behaviour (the cognition). In both the work and relational domain, the influence of adolescents' standards and mental incongruity on the development of their identity was studied. By means of structural equation modelling, we tested hypotheses on a representative sample of Dutch working adolescents, aged 16 to 24 (n=706). As expected, a higher standard in the relational or work domain was related to more exploration and commitment in that domain - and thus to a more developed identity. Work and relational identity were positively related to well-being. Furthermore, positive relations were found between a standard and the mental incongruity in a domain. Finally, mental incongruities were negatively related to identity and only relational incongruity was negatively related to well-being.