The association between perceived social support and parenting self-efficacy among parents of children aged 0-8 years.

Strengthening social support has been recognized as a potentially effective strategy to enhance parenting self-efficacy, but empirical evidence is limited. This study examined the association between perceived social support and parenting self-efficacy.Data of 647 parents of children aged 0-8 years, gathered in the CIKEO cohort study in the Netherlands, were analysed. Data were collected between October 2017 and December 2019. Multivariable linear regression models were used to examine the association between social support and parenting self-efficacy. The mean age of the participants was 33.8 years (SD = 4.9); 94.9% mothers. At the start of the study, 15.1% parents perceived low to moderate social support. Parents who experienced lower levels of social support at the start of the study reported lower parenting self-efficacy at follow-up (ß: 0.13; 95% CI: 0.05, 0.21), independent of potential socio-demographic confounders. Experiencing an increase in perceived social support during the study period was associated with an increase in parenting self-efficacy (ß: 0.15; 95% CI: 0.10, 0.21). Our findings indicate perceived social support is associated with parenting self-efficacy among parents of children aged 0-8 years. Future longitudinal studies need to confirm our findings and may examine which social support interventions are effective in strengthening parenting self-efficacy.

Associations between organised leisure-time activities and mental health problems in children.

Previous studies conducted mainly among adolescents have found associations between participation in sport organised leisure-time activities (OLTAs) and mental health problems (MHP). Fewer research studies have been performed to primary school-aged children and to organised non-sport OLTAs. Therefore, the objective is to examine whether there is an association between participation in sport and non-sport OLTAs and a high risk of MHP in 4- to 12-year-olds. Data were used on 5010 children from a cross-sectional population-based survey conducted between May and July 2018 in Rotterdam, the Netherlands. Associations between sport OLTAs, non-sport OLTAs and breadth of OLTAs and a high risk of MHP were explored using logistic regression models adjusting for sociodemographic characteristics, stressful life events and physical activity. Of all children, 58% participated in sport OLTAs and 22% in non-sport OLTAs. The proportion of children with high risk of MHP among participants in sport OLTAs is smaller than among non-participants (OR 0.66, 95% CI: 0.53, 0.81). The proportion of children with high risk of MHP among participants in non-sport OLTAs is smaller than among non-participants (OR 0.69, 95% CI: 0.53, 0.91). The proportion of children with a high risk of MHP among participants in 1 category of OLTAs (OR 0.61, 95% CI: 0.49, 0.76) and in 2-5 categories of OLTAs (OR 0.48, 95% CI: 0.32, 0.71) is smaller than among non-participants.  Conclusion: The proportion of children with high risk of MHP among participants in OLTAs is smaller than among non-participants. What is Known: • Around 10--20% of children and adolescents experiences mental health problems. • Sport organised leisure-time activities have been found to be associated with a lower risk of mental health problems in adolescents. What is New: • The proportion of children with a high risk of mental health problems in participants in organised leisure-time activities is smaller than among non-participants. • The proportion of children with a high risk of mental health problems in participants with a higher breadth of organised leisure-time activities is smaller compared to non-participants.

Socio-demographic characteristics associated with perceived social support among parents of children aged 0-7 years: the CIKEO study.

BACKGROUND: Social support has been associated with numerous positive outcomes for families' health, wellbeing and empowerment. This study examined which socio-demographic characteristics are associated with perceived social support among parents of children aged 0-7 years. METHOD: Cross-sectional data of 1007 parents of children aged 0-7 years, gathered in the CIKEO cohort study in the Netherlands, were analysed. Social support was assessed with the Multi-dimensional Scale of Perceived Social Support (MSPSS). Linear regression models were used to examine associations between socio-demographic characteristics and perceived social support. RESULTS: The mean age of the participants was 34.1 years (SD = 5.1); 92.9% were mothers. The multivariable regression model showed that fathers (ß: -0.15, 95% CI: - 0.22, - 0.08), parents with a low educational level (ß: -0.12, 95% CI: 0.18, - 0.06), parents with a low income (ß: -0.10, 95% CI: - 0.19, - 0.01), unemployed parents (ß: -0.14, 95% CI: - 0.20, - 0.07), and parents of older children (ß: -0.07; 95% CI: - 0.13, 0.00) perceived lower levels of social support. Interaction analyses showed that parents with a migration background and a low educational level were particularly susceptible to perceiving lower levels of support (ß: -0.34, 95% CI: - 0.52, - 0.15). CONCLUSION: Fathers, parents with a low educational level, parents with a low income, unemployed parents, parents of older children, and parents with both a migration background and a low educational level are at increased risk of perceiving lower levels of social support. IMPLICATIONS: We recommend to develop, implement and evaluate intervention strategies to strengthen perceived social support among the abovementioned subgroups of parents, in order to improve families' health, wellbeing and empowerment. TRIAL REGISTRATION: NTR7607 in the Netherlands trial registry.

Parental, child and socio-contextual factors associated with parenting self-efficacy among parents of children aged 0-7 years old: the CIKEO study.

BACKGROUND: A high parenting self-efficacy (PSE) has been associated with positive parenting and positive child development. However, there is limited and inconsistent information on factors associated with PSE. OBJECTIVE: To investigate factors associated with PSE in parents of children aged 0-7 years old, and to explore whether the associations were different between mothers and fathers. METHODS: We performed a cross-sectional analysis of the baseline data from a prospective cohort study: the CIKEO study. A total of 1012 parents (mean age = 33.8, SD = 5.0) completed self-reported measure of PSE and 18 potential factors associated with PSE. RESULTS: Multivariable models revealed that lower parenting stress, fewer child behavior problems, better eating behavior, better parental and child general health, a smaller number of children living in the household, higher perceived level of social support and having a migration background were associated with higher levels of PSE (p < 0.05). The association between family functioning and PSE differed between mothers and fathers (p for interaction = 0.003): with beta and 95% confidence interval being: 1.29 (- 2.05, 0.87), and 0.23 (- 0.46, 3.29), respectively. CONCLUSIONS: A range of parental, child and social-contextual factors in relation to PSE were identified. The patterns of associations for most of the factors were similar among mothers and fathers. However, the association between family functioning and PSE might differ for mothers and fathers. Our findings are relevant for tailoring and implementing successful interventions and effective policy making in child care. TRIAL REGISTRATION: Netherlands National Trial Register number NL7342. Date of registration: 05-November-2018, retrospectively registered.

Factors associated with parenting self-efficacy: A systematic review.

AIMS: To provide an overview of the parental, child, and socio-contextual factors related to general parenting self-efficacy (PSE) in the general population. DESIGN: Systematic review. DATA SOURCES: Medline Ovid, Web of Science, Embase, and PsycINFO Ovid were systematically searched for studies published between January 1980-June 2020. REVIEW METHODS: Studies were included if they described associations between factor(s) and PSE among parents of children aged 0-18 years old in the general population, and published in an English language peer-reviewed journal. Studies with participants from specific populations, studies describing the development of instruments for PSE, qualitative studies, reviews, theses, conference papers and book chapters were excluded. Belsky's process model of parenting guided the data synthesis. RESULTS: Of 3,819 articles, 30 articles met the inclusion criteria. Eighty-nine factors were identified. There was evidence of associations between child temperament, maternal parenting satisfaction, parenting stress, maternal depression, household income, perceived social support and PSE. Evidence was inconsistent for an association of educational level, parity, number of children in the household and PSE in mothers. There was no evidence of an association for child gender, age, marital status and PSE in both mothers and fathers; ethnicity, age, employment status in mothers; household income in fathers; and educational level, parenting fatigue in parents. CONCLUSION: A range of factors studied in relation to PSE was identified in this systematic review. However, the majority of the factors was reported by one or two studies often implementing a cross-sectional design. IMPACT: There is some evidence for an association between some potentially modifiable factors and PSE in the general population, this information may be used by health and social professionals supporting child health and well-being. Future longitudinal studies are recommended to study parental, child and socio-contextual factors associated with PSE to inform the development of intervention strategies.

Evaluation of the promising neighbourhoods community program to reduce health inequalities in youth: a protocol of a mixed-methods study.

BACKGROUND: Reducing socioeconomic health inequalities among youth is a major challenge for governments around the world and reports on successful attempts are scarce. Socioecological and integral approaches with collaborative partnerships and community engagement are recommended but knowledge about the effectiveness and effective and ineffective elements is limited. The Promising Neighbourhoods program employs such an approach aiming to reduce socioeconomic inequalities in health, safety and talent development in youth. We will evaluate the process-implementation, and effectiveness of the Promising Neighbourhoods program. METHODS/DESIGN: Core elements of Promising Neighbourhoods are a collaborative community programming approach with stakeholders, data-based priority setting, knowledge-, and theory-based policies and evidence-based interventions. Community stakeholders and key-leaders from the neighbourhoods are engaged in the program. For this evaluation study the program will be implemented in three intervention neighbourhoods. These neighbourhoods will be compared to three control neighbourhoods at baseline in 2018/2019 and at follow-up in 2020/2021 after full implementation of the Promising Neighbourhoods program. Intervention neighbourhoods receive a tailored intervention-package including evidence-based interventions and additional measures by community stakeholders. In control neighbourhoods, no special planning will take place thus interventions are offered as usual. A mixed-methods approach following the stages of the logic model from program is applied for this evaluation. Questionnaires, focus groups, and registration data will be collected among community stakeholders, key-leaders, and youth to evaluate the process-implementation of the program. Indicators of intermediate and ultimate outcomes will be studied among N = 818 children and N = 818 youngsters using difference-in-difference regression analysis to evaluate the effectiveness of the Promising Neighbourhoods program. DISCUSSION: Hypotheses are that a collaborative community approach with stakeholders leads to clear priority-setting and better tailored interventions of better quality. We further hypothesise a decline in socioeconomic inequalities in intermediate and ultimate outcomes for health, safety and talent development in the intervention neighbourhoods in comparison to control neighbourhoods. The results add knowledge about effective and ineffective elements of collaborative community programming approaches to reduce health inequalities in youth and thus are relevant for local and national public health authorities. TRIAL REGISTRATION: Netherlands National Trial Register number NL7279 . Date of registration: 26-Sept-2018.

Evaluation of effectiveness of (elements of) parenting support in daily practice of preventive youth health care; design of a naturalistic effect evaluation in 'CIKEO' (consortium integration knowledge promotion effectiveness of parenting interventions).

BACKGROUND: The number of interventions to support parents is growing. The level of evidence regarding these intervention varies. In this paper we describe a study that aims to assess the effectiveness of specific 'elements' within such parenting interventions for families with children up to 7 years. A naturalistic effect evaluation will be applied. Study questions are: 1. What is the exposure of parents to (elements of) parenting interventions in the daily practice of preventive youth health care? 2. What are the associations between the exposure to (elements of) parenting interventions and outcomes in parents/children related to parenting and child development? METHODS/DESIGN: Thousand parents/caregivers are recruited by preventive youth health care providers in the Netherlands. Measurements will be performed after inclusion and after 12-months follow up. Data regarding child/parent/caregiver characteristics, use of (parenting) interventions and care, and outcomes with regard to parenting skills, family functioning and child development will be collected. Outcomes will be compared between parents/children exposed and non-exposed to the (elements of) parenting interventions (adjusting for confounders). DISCUSSION: We hypothesize that parents/caregivers with exposure to (elements of) parenting interventions show (relatively more) improvements in parenting outcomes. Results will support intervention selection/development, and support communities/professionals to select appropriate intervention-elements. TRIAL REGISTRATION: Netherlands National Trial Register number NL7342 . Date of registration: 05-November-2018, retrospectively registered.

Mild perinatal adversities moderate the association between maternal harsh parenting and hair cortisol: Evidence for differential susceptibility.

It has been shown that following exposure to mild perinatal adversity, children have greater susceptibility to both the negative and positive aspects of their subsequent environment. In a large population-based cohort study (N = 1,776), we investigated whether mild perinatal adversity moderated the association between maternal harsh parenting and children's hair cortisol levels, a biomarker of chronic stress. Mild perinatal adversity was defined as late preterm birth (gestational age at birth of 34-37 weeks, 6 days) or small for gestational age (birth weight between the 2.5th and 10th percentile for full term gestational age). Harsh parenting was assessed by maternal self-report at 3 years. Children's hair cortisol concentrations were measured from hair samples collected at age 6. There were no significant bivariate associations between mild perinatal adversities and harsh parenting and hair cortisol. However, mild perinatal adversities moderated the association between maternal harsh parenting and hair cortisol levels. Children with mild perinatal adversity had lower cortisol levels if parented more harshly and higher cortisol levels in the absence of harsh parenting than children who did not experience mild perinatal adversity. These results provide further evidence that mild perinatal adversity is a potential marker of differential susceptibility to environmental influences.

Differential susceptibility in a developmental perspective: DRD4 and maternal sensitivity predicting externalizing behavior.

This study is the first to investigate the longitudinal effects of gene-environment interplay between DRD4 genotype and maternal sensitivity on child externalizing behavior. Multiple measures of maternal sensitivity (14, 36, and 48 months) and externalizing behavior (18 months, 36 months, and 5 years) were assessed in a large cohort study (N = 548). Early maternal insensitivity (14 months) was associated with early externalizing behavior (18 months) in a for better and for worse manner, but only in children with at least one DRD4 7-repeat, consistent with a differential susceptibility model. Later insensitivity (48 months) predicted externalizing behavior at age 5 independent of DRD4 genotype. A structural equation model including all measures across time supported the differential susceptibility model: The overall effect of early maternal sensitivity on later externalizing behavior was significant only for children with a DRD4 7-repeat allele. The results highlight the importance of studying gene-environment interactions across development.

The effects and process of the intervention "Individual Shantala Infant Massage" in preventive child healthcare to improve parent-child interaction: study protocol for a quasi-experimental study.

BACKGROUND: Individual Shantala Infant Massage is an intervention that is offered by several Dutch Preventive Child Healthcare (PCH) organizations as optional preventive support, in addition to basic care as offered to all children. It targets vulnerable families and aims to enhance sensitive parenting and to reduce (effects of) parental stress. The intervention is carried out by a certified nurse. It consists of three structured home visits. Parents learn to massage their infant and receive parenting support. This study aims to investigate the effectiveness and the process of the intervention. The main hypothesis is that Individual Shantala Infant Massage leads to increased parental sensitive responsiveness, lower perceived and physiological parental stress, and improved child growth and development in the intervention group, compared to a control group where this intervention is not offered by PCH. Secondary research questions address effects on parenting confidence and parental concerns regarding the infant, the influence of background characteristics and the intervention process. METHODS: The study is a quasi-experimental non-randomized trial. The aim is to include 150 infant-parent dyads in both the intervention and the control group. This takes into account possible attrition and missing data as 105 dyads with complete data per group are sufficient for analysis. All participants complete questionnaires at T0 (pre-test, child age between six-sixteen weeks), T1 (post-intervention, or ± four weeks after T0), and T2 (follow-up at five months). At T2, a hair tuft is cut from the parents' head to measure hair cortisol levels. Data on infant growth and development is obtained from PCH files. In the intervention group, additional data is collected to evaluate the intervention process: parents complete an evaluation questionnaire at T1, nurses keep semi-structured logbooks of intervention sessions and interviews are conducted with parents and professionals. DISCUSSION: Study results can contribute to the evidence base of infant massage as applied in Dutch PCH, and can inform parents, PCH practitioners, policy makers and researchers both inside and outside the Netherlands on feasibility and effectiveness of the infant massage intervention as applied in this format and setting. TRIAL REGISTRATION: ISRCTN registry: ISRCTN16929184. Date (retrospectively) registered: 29/03/2022.

Longitudinal associations between parent, child, family factors and dyssomnias in children from birth to 8 years: The CIKEO study.

BACKGROUND: Dyssomnias, are the most common parent-reported sleep complaints in young children. The present study investigated the prevalence, one-year development (incidence and persistence) of dyssomnia in early childhood, and the parent, child, and family factors associated with dyssomnia. METHODS: Longitudinal data of 700 children aged 0-8, gathered in the CIKEO cohort study in the Netherlands were analyzed. Dyssomnias were defined as the presence of night awakenings ≥3 times per night or sleep-onset latency of >30 min. Least absolute shrinkage and selection operator (LASSO) was used to identify the parental, child, and family factors associated with the incidence and persistence of dyssomnias in children. RESULTS: The mean age of the children (47 % girls) was 3.2 ± 1.9 years at baseline and 4.4 ± 1.8 years at follow-up. The prevalence of dyssomnias was 13.3 % and 15.4 % at baseline and follow-up, respectively. The incidence and persistence rates of dyssomnias at follow-up were 12.0 % and 37.6 %, respectively. New incidence of insomnia was associated with being a girl, having medical conditions, experiencing stressful life events, and lower parenting self-efficacy at baseline (P < 0.05). Higher levels of parental psychological distress were associated with the persistence of dyssomnias in children (P < 0.05). CONCLUSIONS: Dyssomnias are common with a moderate persistent rate in young children. Several parental, child, and family factors in relation to the incidence and persistence of dyssomnias were identified. Preventive programs and interventions targeting modifiable factors, particularly parental psychological distress, parenting self-efficacy, and resilience to stressful life events, might benefit child sleep.

Associations of socioeconomic status indicators and migrant status with risk of a low vegetable and fruit consumption in children.

BACKGROUND: It is important to provide insight in potential target groups for interventions to reduce socioeconomic inequalities in children's vegetable/fruit consumption. In earlier studies often single indicators of socioeconomic status (SES) or migrant status have been used. However, SES is a multidimensional concept and different indicators may measure different SES dimensions. Our objective is to explore multiple associations of SES indicators and migrant status with risk of a low vegetable/fruit consumption in a large multi-ethnic and socioeconomically diverse sample of children. METHODS: We included 5,010 parents of 4- to 12-year-olds from a Dutch public health survey administered in 2018. Cross-sectional associations of parental education, material deprivation, perceived financial difficulties, neighbourhood socioeconomic status (NSES) and migrant status with low (≤4 days a week) vegetable and fruit consumption in children were assessed using multilevel multivariable logistic regression models. Results are displayed as odds ratios (OR) with 95% confidence intervals (CI). RESULTS: Of the 4- to 12-year-olds, 22.1% had a low vegetable consumption and 11.9% a low fruit consumption. Low (OR 2.51; 95%CI: 2.05, 3.07) and intermediate (OR 1.83; 95%CI: 1.54, 2.17) parental education, material deprivation (OR 1.45; 95%CI: 1.19, 1.76), low NSES (OR 1.28; 95%CI: 1.04, 1.58) and a non-Western migrant status (OR 1.94; 95%CI: 1.66, 2.26) were associated with a higher risk of a low vegetable consumption. Low (OR 1.68; 95%CI: 1.31, 2.17) and intermediate (OR 1.39; 95%CI: 1.12, 1.72) parental education and material deprivation (OR 1.63; 95%CI: 11.27, 2.08) were also associated with a higher risk of a low fruit consumption. CONCLUSION: Our findings indicate associations of multiple SES indicators and migrant status with a higher risk of a low vegetable/fruit consumption in children and thus help to identify potential target groups.

A prospective study on the association between social support perceived by parents of children aged 1-7 years and the use of community youth health care services.

Aim: This study examined the association between social support perceived by parents of children aged 1-7 years and the use of additional community youth health care services. Methods: Data of 749 parents of children aged 1-7 years, gathered in the CIKEO cohort study in the Netherlands, were analyzed. Social support was assessed with the Multidimensional Scale of Perceived Social Support. Data on the use of additional community youth health care services during a period of 1.5 years were obtained from the electronic records of participating youth health care organizations. Multivariable logistic regression models were used to examine the association between perceived social support and the use of additional youth health care services and to explore moderation by the parent's educational level. Results: The mean age of the responding parents was 33.9 years (SD = 5.1); 93.6% were mothers. Parents who perceived low to moderate levels of social support had 1.72 (95% CI: 1.11, 2.66) times higher odds of using one or more additional youth health care services during the study period compared to parents who perceived high levels of social support at baseline. This association was independent of predisposing factors, but not independent of need factors (p > 0.05). Furthermore, the association was moderated by the educational level of the parent (p = 0.015). Among parents with a high educational level, low to moderate levels of perceived social support at baseline were associated with 2.93 (95% CI: 1.47, 5.83) times higher odds of using one or more additional youth health care services during the study period independent of predisposing and need factors. Among parents with a low or middle educational level the association between perceived social support and use of additional youth health care services was not significant. Conclusion: Our findings provide evidence that low to moderate levels of perceived social support are associated with a higher use of additional community youth health care services among parents of children aged 1-7 years, especially among high educated parents. Recommendations for policy and practice are provided.

Factors associated with media use for parenting information: A cross-sectional study among parents of children aged 0-8 years.

AIM: Media use may strengthen parents' capacities to deal with parenting issues. This study examined which factors are associated with media use for parenting information. DESIGN: Cross-sectional data of 658 parents of children aged 0-8 years, gathered in the CIKEO cohort study in the Netherlands, were analysed. METHODS: Multivariable logistic regression models were used to examine which factors were associated with media use for parenting information. RESULTS: The mean age of the participants was 33.8 years (SD = 5.0); 94.7% were mothers; 77.4% used media for parenting information. Parents with more questions or concerns (OR: 1.40, 95% CI: 1.23, 1.59), and parents who received parenting information from their social contacts (OR: 5.57, 95% CI: 3.22, 9.61), had higher odds of media use for parenting information. Older parents (OR: 0.95, 95% CI: 0.91, 1.00), and parents of older children (OR: 0.84, 95% CI: 0.74, 0.95), had lower odds of media use for parenting information.

The Association between Stressful Life Events and Emotional and Behavioral Problems in Children 0-7 Years Old: The CIKEO Study.

BACKGROUND: Stressful life events (SLEs) are recognized risk factors for emotional and behavioral problems, but the association is understudied among young children. Our aim was to examine the association between exposure to SLEs and emotional and behavioral problems in young children up to 7 years old. METHODS: We analyzed baseline data from 959 children (mean age = 3.3 years; SD = 1.9; 47.5% girls) in the CIKEO study, a community-based longitudinal study in the Netherlands. Linear regression was used to assess the associations between the total as well as the individual exposure to SLEs experienced in the past 12 months, and emotional and behavioral problems assessed by CBCL 1.5-5. Interactions of SLEs and child age, sex, ethnic background, and socioeconomic status were explored. RESULTS: Higher total exposure to SLEs, as indicated by the number of SLEs, was significantly associated with higher CBCL total, internalizing and externalizing problem scores (p for trend < 0.05). The results did not differ by child age, sex, ethnic background, or family SES. Six out of the 12 SLEs explored were independently associated with greater CBCL total/externalizing/internalizing scores (p < 0.05). CONCLUSIONS: Exposure to SLEs is associated with higher levels of emotional and behavioral problems in young children, and the impact of SLEs may vary depending on the types of events. Stressful life events might be a useful target for interventions to improve emotional and behavioral well-being among young children.

Feasibility and validity of the Health Status Classification System-Preschool (HSCS-PS) in a large community sample: the Generation R study.

OBJECTIVES: To evaluate the feasibility, discriminant validity and concurrent validity of the Health Status Classification System-Preschool (HSCS-PS) in children aged 3 years in a large community sample in the Netherlands. DESIGN/SETTING: A prospective population-based cohort in Rotterdam, the Netherlands. PARTICIPANTS: A questionnaire was administrated to a sample of parents of 4546 children (36.7±1.5 months). OUTCOME MEASURES: Health-related quality of life (HRQOL) of children was measured by HSCS-PS. The HSCS-PS consists of 10 original domains. Two single-item measures of 'General health' and 'Behavior' were added. A disability score was calculated by summing up all 10 original domains to describe the overall health status. Feasibility was assessed by the response rate, percentages of missing answers, score distributions and the presence of floor/ceiling effects. Discriminant validity was analysed between subgroups with predefined conditions: low birth weight, preterm birth, wheezing, Ear-Nose-Throat surgical procedures and behaviour problems. In the absence of another HRQOL measure, this study uses the single-items 'General health' and 'Behavior' as a first step to evaluate concurrent validity of the HSCS-PS. RESULTS: Feasibility: response rate was 69%. Ceiling effects were observed in all domains. Discriminant validity: the disability score discriminated clearly between subgroups of children born with a 'very low birth weight', 'very preterm birth', with 'four or more than four times wheezing', 'at least one ear-nose-throat surgical procedures', 'behaviour problems present' and the 'reference' group. Concurrent validity: HSCS-PS domains correlated better with hypothesised parallel additional domains than with other non-hypothesised original domains. CONCLUSIONS: This study supports the feasibility and validity of the HSCS-PS among preschoolers in community settings. We recommend developing a utility-based scoring algorithm for the HSCS-PS. Further empirical studies and repeated evaluations in varied populations are recommended.

Beyond main effects of gene-sets: harsh parenting moderates the association between a dopamine gene-set and child externalizing behavior.

BACKGROUND: In a longitudinal cohort study, we investigated the interplay of harsh parenting and genetic variation across a set of functionally related dopamine genes, in association with children's externalizing behavior. This is one of the first studies to employ gene-based and gene-set approaches in tests of Gene by Environment (G × E) effects on complex behavior. This approach can offer an important alternative or complement to candidate gene and genome-wide environmental interaction (GWEI) studies in the search for genetic variation underlying individual differences in behavior. METHODS: Genetic variants in 12 autosomal dopaminergic genes were available in an ethnically homogenous part of a population-based cohort. Harsh parenting was assessed with maternal (n = 1881) and paternal (n = 1710) reports at age 3. Externalizing behavior was assessed with the Child Behavior Checklist (CBCL) at age 5 (71 ± 3.7 months). We conducted gene-set analyses of the association between variation in dopaminergic genes and externalizing behavior, stratified for harsh parenting. RESULTS: The association was statistically significant or approached significance for children without harsh parenting experiences, but was absent in the group with harsh parenting. Similarly, significant associations between single genes and externalizing behavior were only found in the group without harsh parenting. Effect sizes in the groups with and without harsh parenting did not differ significantly. Gene-environment interaction tests were conducted for individual genetic variants, resulting in two significant interaction effects (rs1497023 and rs4922132) after correction for multiple testing. CONCLUSION: Our findings are suggestive of G × E interplay, with associations between dopamine genes and externalizing behavior present in children without harsh parenting, but not in children with harsh parenting experiences. Harsh parenting may overrule the role of genetic factors in externalizing behavior. Gene-based and gene-set analyses offer promising new alternatives to analyses focusing on single candidate polymorphisms when examining the interplay between genetic and environmental factors.

Splitting hair for cortisol? Associations of socio-economic status, ethnicity, hair color, gender and other child characteristics with hair cortisol and cortisone.

The aim of this study was to examine associations of SES and ethnicity with hair cortisol and cortisone and to identify potential child and family characteristics that can assist in choosing covariates and potential confounders for analyses involving hair cortisol and cortisone concentrations. Hair samples were collected in 2484 6-year-old children from the Generation R Study, a prospective cohort in Rotterdam, the Netherlands. Measurements for cortisol and cortisone were used as the outcome in regression analyses. Predictors were SES, ethnicity, hair color and child characteristics such as birthweight, gestational age at birth, BMI, disease, allergy, and medication use. Lower family income, more children to be supported by this income, higher BMI and darker hair color were associated with higher hair cortisol and cortisone levels. Boys also showed higher levels. Ethnicity (Dutch and North European descent) was related to lower levels. High amounts of sun in the month of hair collection was related to higher levels of cortisone only. More recent hair washing was related to lower levels of cortisol and cortisone. Gestational age at birth, birth weight, age, medication use, hair washing frequency, educational level of the mother, marital status of the mother, disease and allergy were not associated with cortisol or cortisone levels. Our results serve as a starting point for choosing covariates and confounders in studies of substantive predictors or outcomes. Gender, BMI, income, the number of persons in a household, ethnicity, hair color and recency of hair washing are strongly suggested to take into account.

Developmental change in intentional action and inhibition: a heart rate analysis.

The ability to inhibit is a major developmental dimension. Previous studies examined developmental change in instructed inhibition. The current study, however, focused on intentional inhibition. We examined heart rate responses to intentional action and inhibition, with a focus on developmental differences. Three age groups (8-10, 11-12, and 18-26 years) performed a child-friendly marble paradigm in which they had to choose between intentionally acting on, or inhibiting, a prepotent response. As instructed, all age groups chose to intentionally inhibit on approximately 50 percent of the intentional trials. A pronounced heart rate deceleration was observed during both intentional action and intentional inhibition, but this deceleration was most pronounced for intentional inhibition. Heart rate responses did not differentiate between age groups, suggesting that intentional action and inhibition reach mature levels early in childhood.