Stress and anxiety during pregnancy and length of gestation: a federated study using data from five Canadian and European birth cohorts.

While its etiology is not fully elucidated, preterm birth represents a major public health concern as it is the leading cause of child mortality and morbidity. Stress is one of the most common perinatal conditions and may increase the risk of preterm birth. In this paper we aimed to investigate the association of maternal perceived stress and anxiety with length of gestation. We used harmonized data from five birth cohorts from Canada, France, and Norway. A total of 5297 pregnancies of singletons were included in the analysis of perceived stress and gestational duration, and 55,775 pregnancies for anxiety. Federated analyses were performed through the DataSHIELD platform using Cox regression models within intervals of gestational age. The models were fit for each cohort separately, and the cohort-specific results were combined using random effects study-level meta-analysis. Moderate and high levels of perceived stress during pregnancy were associated with a shorter length of gestation in the very/moderately preterm interval [moderate: hazard ratio (HR) 1.92 (95%CI 0.83, 4.48); high: 2.04 (95%CI 0.77, 5.37)], albeit not statistically significant. No association was found for the other intervals. Anxiety was associated with gestational duration in the very/moderately preterm interval [1.66 (95%CI 1.32, 2.08)], and in the early term interval [1.15 (95%CI 1.08, 1.23)]. Our findings suggest that perceived stress and anxiety are associated with an increased risk of earlier birth, but only in the earliest gestational ages. We also found an association in the early term period for anxiety, but the result was only driven by the largest cohort, which collected information the latest in pregnancy. This raised a potential issue of reverse causality as anxiety later in pregnancy could be due to concerns about early signs of a possible preterm birth.

Transactional associations between vocabulary and disruptive behaviors during the transition to formal schooling.

This study investigated the transactional relations between vocabulary and disruptive behaviors (DB; physical aggression and opposition/rule breaking/theft and vandalism), during the transition to formal schooling, using a community sample of 572 children. Cross-lagged panel model analyses were used to examine bidirectional relationships, comparing physical aggression to non-aggressive DB. Transactional associations between vocabulary and DB were observed, coinciding with school entry. Lower vocabulary in preschool (60mo.) was predictive of higher physical aggression scores in kindergarten. In turn, higher physical aggression in kindergarten was predictive of lower vocabulary in 1st grade. For non-aggressive DB, recurrent associations were found. Lower verbal skills in preschool (42mo.) and kindergarten predicted higher non-aggressive DB scores later in preschool and in 1st grade respectively. In turn, higher non-aggressive DB in kindergarten predicted lower vocabulary scores in 1st grade. In contrast to transactional paths from vocabulary to DB, transactional paths from DB to vocabulary observed after the transition to elementary school remained significant after controlling for comorbid hyperactivity, impulsivity and inattention behaviors, suggesting these links were specific to aggressive and non-aggressive DB. Practical implications for prevention are discussed.

Heterogeneity in the Course of Suicidal Ideation and its Relation to Suicide Attempts in First-Episode Psychosis: A 5-Year Prospective Study.

OBJECTIVES: Although the risk of suicide is high in first-episode psychosis (FEP), little is known about the course of suicidal ideation and its relation to suicide attempts. Therefore, we aimed to identify 5-year trajectories of suicidal ideation and associated factors in FEP and compare how suicide attempts were distributed across these identified trajectories. METHOD: This 5-year prospective study assessed suicidal ideation, suicide attempts and potentially associated factors through research interviews, chart review and coroners' reports in 382 FEP patients [mean age = 23.53 (SD = 3.61)] admitted to 2 5-year early psychosis services in Montreal, Canada. Trajectories were identified using a semiparametric mixture model, and associated factors with multinomial logistic regression. RESULTS: Three suicidal ideation trajectories were identified: low and decreasing (n = 325, 85.08%); early decline, then increasing (n = 30, 7.85%), and persistent suicidal ideation (n = 27, 7.07%). Suicidal ideation prior to admission (OR = 2.85, 95% CI, 1.23 to 6.63, P < 0.05) and cocaine use disorder (OR = 6.78, 95% CI, 1.08 to 42.75, P < 0.05) were associated with the early decline, then increasing suicidal ideation trajectory. Persons with prior suicide ideation (OR = 4.33, 95% CI, 1.66 to 11.29, P < 0.05) and attempts (OR = 8.18, 95% CI, 2.39 to 27.97, P < 0.001) and alcohol use disorder (OR = 3.63, 95% CI, 1.4 to 9.42, P < 0.05) were more likely to belong to the persistent suicidal ideation trajectory, and to attempt suicide during follow-up. CONCLUSIONS: Our study highlights heterogeneity in the course of suicidal ideation over 5 years and the importance of ongoing assessment of suicidal risk in FEP patients, particularly for patients who persistently report suicidal ideation, as they are likelier to engage in suicide attempts. Patients with factors associated with increasing or persistent suicidal ideation trajectories should be targeted for suicide prevention interventions from the early phase of follow-up. Given the small number of persons in these trajectories and the wide CIs for some factors, larger studies are however needed to further characterize who belongs in each group.

A genetically informed study on the association of cannabis, alcohol, and tobacco smoking with suicide attempt.

Use of substances such as cannabis, alcohol, and tobacco, has been associated with increased risk of suicide attempt in several observational studies. However, establishing whether these associations are causal is challenging when using observational designs. To evaluate the potential causal contributions of cannabis use, alcohol use, and tobacco smoking to suicide attempt, we applied two-sample Mendelian randomization, an instrumental variable approach using single-nucleotide polymorphisms (SNPs) as instrumental variables for three exposures: lifetime cannabis use (yes/no; 42 instrument SNPs; GWAS sample size [N] = 162,082), alcohol use (drinks-per-week; 53 instrument SNPs; N = 941,280), and tobacco smoking (initiation, yes/no; 156 instrument SNPs; N = 1,232,091; heaviness; 27 instrument SNPs; N = 337,334). The main outcome was suicide attempt measured from hospital records (N = 50,264). All data come from publicly available summary statistics of genome-wide association studies of participants of European ancestry. We found evidence supporting a possible causal role of cannabis (OR = 1.18; 95% CI = 1.01-1.37, P = 0.032), alcohol (OR = 1.95; 95% CI = 1.15-3.32, P = 0.013), and smoking (initiation, OR = 1.90; 95% CI = 1.54-2.34, P < 0.001; heaviness, OR = 2.13; 95% CI = 1.13-3.99; P = 0.019) on suicide attempt. Using multivariable Mendelian randomization, we found that only cannabis showed a direct pathway to suicide attempt (P = 0.001), suggesting that the effect of alcohol and smoking was mediated by the other substance use phenotypes. No evidence was found for reverse causation, i.e., associations of suicide attempt on cannabis (P = 0.483), alcohol (P = 0.234), smoking initiation (P = 0.144), and heaviness (P = 0.601). In conclusion, evidence from this quasi-experimental study based on genetic data from large-scale GWASs are consistent with a causal role of cannabis, alcohol, and tobacco smoking on suicide attempt.

Transactional longitudinal relations between accuracy and reaction time on a measure of cognitive flexibility at 5, 6, and 7 years of age.

Whereas accuracy is used as an indicator of cognitive flexibility in preschool-age children, reaction time (RT), or a combination of accuracy and RT, provide better indices of performance as children transition to school. Theoretical models and cross-sectional studies suggest that a speed-accuracy tradeoff may be operating across this transition, but the lack of longitudinal studies makes this transition difficult to understand. The current study explored the longitudinal and bidirectional associations between accuracy and RT on the DCCS (mixed block) at 5, 6, and 7 years of age using cross-lagged panel analyses. The study also examined the roles of working memory and language, as potential longitudinal mediators between RT at Time X and accuracy at Time X + 1, and explored the role of inhibitory control. The sample consisted of 425 children from the Quebec Longitudinal Study of Child Development. Results show lagged associations from slower RT to greater improvements in accuracy between 5 and 6 years and between 6 and 7 years. Further, higher accuracy at 6 years predicted faster RT at 7 years. Only working memory acted as a partial mediator between RT at 5 years and accuracy at 6 years. These results provide needed longitudinal evidence to support theoretical claims that slower RT precedes improved accuracy in the development of cognitive flexibility, that working memory may be involved in the early stage of this process, and that accuracy and reaction time become more efficient in later stages of this process.

Prefrontal cortex and amygdala anatomy in youth with persistent levels of harsh parenting practices and subclinical anxiety symptoms over time during childhood.

Childhood adversity and anxiety have been associated with increased risk for internalizing disorders later in life and with a range of brain structural abnormalities. However, few studies have examined the link between harsh parenting practices and brain anatomy, outside of severe maltreatment or psychopathology. Moreover, to our knowledge, there has been no research on parenting and subclinical anxiety symptoms which remain persistent over time during childhood (i.e., between 2.5 and 9 years old). Here, we examined data in 94 youth, divided into four cells based on their levels of coercive parenting (high / low) and of anxiety (high / low) between 2.5 and 9 years old. Anatomical images were analyzed using voxel-based morphometry (VBM) and FreeSurfer. Smaller gray matter volumes in the prefrontal cortex regions and in the amygdala were observed in youth with high versus low levels of harsh parenting over time. In addition, we observed significant interaction effects between parenting practices and subclinical anxiety symptoms in rostral anterior cingulate cortical thickness and in amygdala volume. These youth should be followed further in time to identify which youth will or will not go on to develop an anxiety disorder, and to understand factors associated with the development of sustained anxiety psychopathology.

Associations of childhood sociability and responsibility with cannabis use trajectories during adolescence: results from a prospective population-based birth cohort study.

This study aims to identify distinct trajectories of cannabis use during adolescence and examine whether Sociability (ability to relate to others) and Responsibility (ability to integrate a community setting) during childhood are associated with these trajectories, accounting for individual and familial confounders. Population-based cohort study (1998-2019): 1511 children from the Quebec Longitudinal Study of Child Development were followed between ages 5 months and 19 years. We identified developmental trajectories of adolescent cannabis use (assessed biyearly between ages 12 and 19 years) using a group-based trajectory model. We performed multinomial regression analyses to estimate the association between childhood Sociability and Responsibility assessed yearly between ages 6 and 12 years, and cannabis use trajectories. At 19 years, 62.8% (807/1286) of adolescents had used cannabis at least once in their lifetime, 44.2% had used at least once in the past 12 months (504/1140), and 6.8% were reporting daily use (77/1140). We identified three cannabis use trajectories: nonusers (n = 577, 38.2%), late users (n = 690, 45.7%; mean age of initiation: 16.2 ± 1.6), and early users (n = 244, 16.2%; mean age of initiation: 14.1 ± 1.3). Compared with Nonusers, children with low Sociability had a lower risk for late (OR, 0.43; 95 CI 0.27; 0.68) and early (OR, 0.22; 95 CI 0.12; 0.41) cannabis use. Children with low Responsibility were at higher risk of being Early users (OR, 2.23; 95 CI 1.13; 4.37) but not Late users (OR, 1.20; 95 CI 0.71; 2.03). Understanding the multiple dimensions of social skills and their association with cannabis use trajectories may help improve the effectiveness of evidence-based prevention strategies.

Trajectories of adolescent poly-substance use and their long-term social and economic outcomes for males from low-income backgrounds.

Substance abuse is a significant public health concern that disproportionately burdens males and low-income communities. This study examined (1) longitudinal profiles of male adolescent poly-substance use and (2) their association with social and economic participation across early adulthood. Drawing on a cohort of males (n = 890) from low-income neighborhoods, we used group-based multi-trajectory modeling to identify profiles of poly-substance use (alcohol, tobacco, cannabis, illicit drugs) from age 13-17 years. Regression models were used to link substance use profiles to high school graduation, criminal convictions, personal and household earnings, welfare receipt and partnership from age 19-37 years, obtained from administrative records. Child IQ, family adversity and behavioral problems were adjusted for. Four poly-substance use profiles were identified: abstinent (n = 128, 14.4%), late-onset (n = 412, 46.5%), mid-onset (n = 249, 28.1%), and early-onset (n = 98, 11.1%). Relative to the late-onset (reference) group, participants in the early-onset profile were 3.0 times (95%CI = 1.68-5.53) more likely to have left school without a diploma, 2.7 times (95% CI = 1.56-4.68) more likely to have a criminal conviction by age 24 years, earned 10,185 USD less (95% CI = - 15,225- - 5144) per year at age 33-37 years and had 15,790 USD lower (95% CI = - 23,378- - 8218) household income at age 33-37 years, a 1.3 times (95%CI = 1.15-1.57) higher incidence of annual welfare receipt and a 24% (95% CI = 5-40) lower incidence of marriage/cohabitation from age 18-35 years. We show that adolescent-onset poly-substance use by age 13 is associated with poor social and economic outcomes. Delaying the onset of substance use and reducing exposure to additional substance classes has potential for high societal cost savings.

The 3D-Transition Study: Objectives, Methods, and Implementation of an Innovative Planned Missing-Data Design.

The prevalence of mental health problems represents a significant burden on school and community health resources as early as preschool. Reducing this burden requires a better understanding of the developmental mechanisms linking children's early vulnerabilities with mental health after the transition to formal schooling. The 3D-Transition Study (2017-2021) follows 939 participants from a pregnancy cohort in the province of Québec, Canada, as they transition to kindergarten and first grade to examine these mechanisms. Biannual assessments include completed questionnaires from 2 parents as well as teachers, parent-child observations, anthropometric measurements, and age-sensitive cognitive assessments. Saliva is also collected on 11 days over a 16-month period in a subsample of 384 participants to examine possible changes in child salivary cortisol levels across the school transition and their role in difficulties observed during the transition. A combination of planned missing-data designs is being implemented to reduce participant burden, where incomplete data are collected without introducing bias after the use of multiple imputation. The 3D-Transition Study will contribute to an evidence-based developmental framework of child mental health from pregnancy to school age. In turn, this framework can help inform prevention programs delivered in health-care settings during pregnancy and in child-care centers, preschools, and schools.

Polygenic scores differentially predict developmental trajectories of subtypes of social withdrawal in childhood.

BACKGROUND: Children who consistently withdraw from social situations face increased risk for later socioemotional difficulties. Twin studies indicate that genetic factors substantially account for the persistence of social withdrawal over time. However, the molecular genetic etiology of chronic courses of social wariness and preference for solitude, two dimensions of social withdrawal, remains undocumented. The objectives of the present study were (a) to identify high-risk trajectories for social wariness and preference for solitude in childhood and (b) to examine whether falling on these high-risk trajectories can be predicted by specific polygenic scores for mental health traits and disorders and by a general polygenic predisposition to these traits. METHODS: Teachers evaluated 971 genotyped children at five occasions (age 6 to 12 years) from two prospective longitudinal studies, the Quebec Newborn Twin Study and the Quebec Longitudinal Study of Child Development. Developmental trajectories for social wariness and preference for solitude were identified. We tested whether polygenic scores for attention deficit hyperactivity disorder, autism spectrum disorder, depression, loneliness, and subjective well-being, as well as a general mental health genetic risk score derived across these traits, were associated with the developmental trajectories. RESULTS: Polygenic scores differentially predicted social wariness and preference for solitude. Only the loneliness polygenic score significantly predicted the high trajectory for social wariness. By contrast, the general mental health genetic risk score factor was associated with the trajectory depicting high-chronic preference for solitude. CONCLUSIONS: Distinct associations were uncovered between the polygenic scores, social wariness, and preference for solitude.

Maternal Pregnancy Diet Quality Is Directly Associated with Autonomic Nervous System Function in 6-Month-Old Offspring.

BACKGROUND: Many pregnant women are consuming diets of poor overall quality. Although many studies have linked poor prenatal diet quality to an increased risk of specific diseases in offspring, it is not known if exposure to poor prenatal diet affects core neurophysiological regulatory systems in offspring known to lie upstream of multiple diseases. OBJECTIVE: We aimed to examine the association between prenatal diet quality and autonomic nervous system (ANS) function in infants at 6 mo of age. METHODS: Data from 400 women (aged >18 y, with uncomplicated pregnancies) and their infants participating in the Maternal-Infant Research on Environmental Chemicals-Infant Development cohort were used to investigate links between prenatal diet quality and infant ANS function at 6 mo of age. Prenatal diet quality was assessed using the Healthy Eating Index (2010), calculated from a validated FFQ completed by women during the first trimester. Infant ANS function was measured using 2 assessments of heart rate variability (HRV) including root mean square of successive differences (RMSSD) and SD of N-N intervals (SDNN). Associations were analyzed before and after adjustment for socioeconomic status, maternal depression symptoms, maternal cardiometabolic dysfunction, breastfeeding, and prenatal smoking. RESULTS: Poorer prenatal diet quality was associated with lower infant HRV assessed using RMSSD (B: 0.07; 95% CI: 0.01, 0.13; R2 = 0.013) and SDNN (B: 0.18; 95% CI: 0.02, 0.35; R2 = 0.011). These associations remained significant after adjustment for confounding variables [RMSSD: B: 0.09; 95% CI: 0.003, 0.18; squared semipartial correlation (sp2) = 0.14 and SDNN B: 0.24; 95% CI: 0.0, 0.49; sp2 = 0.13]. CONCLUSIONS: In a large cohort study, poorer prenatal diet quality was associated with lower offspring HRV, a marker of decreased capacity of the ANS to respond adaptively to challenge. Therefore, poor prenatal diet may play a significant role in the programming of multiple organ systems and could increase general susceptibility to disease in offspring.

Moderation of parenting by inhibitory control in the prediction of the common and unique variance of hyperactivity-impulsivity and inattention.

This study examined whether the interaction between parenting and inhibitory control predicts hyperactivity-impulsivity and inattention in 195 children. Observation data of positive parenting were collected at 4 years, and mother reports of coercive parenting at 5 years, inhibitory control at 6 years, and hyperactivity-impulsivity/inattention at 7 years were obtained. The common and unique variance of hyperactivity-impulsivity and inattention symptoms were examined as outcomes using a bifactor model. Results indicated that positive parenting practices predicted lower levels of hyperactivity-impulsivity/inattention behaviors at age 7 only when children's inhibitory control was high. These results support the vantage sensitivity model, which posits that some individuals show an increased sensitivity to positive experiences exclusively, and support the appropriateness of a targeted prevention approach in early childhood.

Maternal depression symptoms, child behavior problems, and their transactional relations: Probing the role of formal childcare.

Among children exposed to elevated maternal depression symptoms (MDS), recent studies have demonstrated reduced internalizing and externalizing problems for those who have attended formal childcare (i.e., center-based, family-based childcare). However, these studies did not consider whether childcare attendance is associated with benefits for the child only or also with reduced MDS. Using a four-wave longitudinal cross-lagged model, we evaluated whether formal childcare attendance was associated with MDS or child behavior problems and whether it moderated longitudinal associations between MDS and child behavior problems and between child behavior problems and MDS. The sample was drawn from a population-based cohort study and consisted of 908 biologically related mother-child dyads, followed from 5 months to 5 years. Attending formal childcare was not associated with MDS or child behavior problems but moderated the association between MDS at 3.5 years and child internalizing and externalizing problems at 5 years as well as between girls' externalizing problems at 3.5 years and MDS at 5 years. No other moderation of formal childcare was found. Findings suggest that attending formal childcare reduces the risks of behavior problems in the context of MDS but also the risk of MDS in the context of girls' externalizing problems.

Maternal depression in early childhood and child emotional and behavioral outcomes at school age: examining the roles of preschool childcare quality and current maternal depression symptomatology.

Recent studies have shown that the association between maternal depression and child outcome can be moderated by children's experience of childcare (e.g., daycare) during early childhood (0-5 years). We also know that maternal depression in the child's early years has long-term associations with child development. However, the moderating role of childcare quality on long-term associations between maternal depression and child outcome has not been thoroughly investigated. This article examined longitudinal associations between probable maternal depression (PMD) during early childhood (0-5 years) and childcare quality on children's emotional and behavioral development at the age of 7-8 years (N = 207). Childcare quality was evaluated through observations within the settings. PMD during early childhood was assessed using complementary information from interviews conducted with the mother and current maternal symptoms were assessed using the Center for Epidemiologic Studies Depression Scale. Internalizing and externalizing behaviors were reported by the mother, father and the child at age 7-8 years. Results indicate that when mothers reported clinically relevant depression in early childhood, 7-8-year-old children demonstrate fewer behavioral problems if they attended a higher quality childcare setting. The moderating role of childcare quality remained after considering current maternal depression symptoms. Therefore, it is important to ensure high-quality childcare during early childhood to optimize child development.

Effect of (Z)-isomer content on [11C]ABP688 binding potential in humans.

PURPOSE: To determine how the low-affinity (Z)-isomer of the radiotracer [11C]ABP688 affects binding potential values in vivo in humans. METHODS: High-resolution [11C]ABP688 PET scans were acquired on 74 healthy volunteers (25 male, 49 female, mean age 20 ± 3.0). The relative contents of (E)- and (Z)-isomers were determined prior to injection using analytical high-performance liquid chromatography [rt(E) = 10 min, rt(Z) = 8.5 min]. Mean binding potential [BPND = fND * (Bavail/KD)] values were calculated in the striatum, limbic regions, and prefrontal cortex using the simplified reference tissue model with cerebellar grey matter as reference. RESULTS: Mean ± SD (E)-isomer content in [11C]ABP688 production was 92 ± 3.8% (range 78-97%). Percent (E)-isomer was positively correlated with BPND in the striatum (ρ = 0.28, p = 0.015) and limbic regions (ρ = 0.25, p = 0.036). In multiple regression analysis, sex (ß = 0.39, p = 0.001) and (E)-isomer content (ß = 0.23, p = 0.040) were significant predictors of BPND. CONCLUSIONS: Even modest levels of (Z)-[11C]ABP688 can reduce estimates of tracer binding in vivo. Future studies should use production methods that enrich levels of (E)-[11C]ABP688, report tracer isomer ratios, and account for this factor in their analyses.

Sex differences in [11C]ABP688 binding: a positron emission tomography study of mGlu5 receptors.

PURPOSE: The purpose of this study was to assess, in a large sample of healthy young adults, sex differences in the binding potential of [11C]ABP688, a positron emission tomography (PET) tracer selective for the metabotropic glutamate type 5 (mGlu5) receptor. METHODS: High resolution [11C]ABP688 PET scans were acquired in 74 healthy volunteers (25 male, 49 female, mean age 20 ± 3.0). Mean binding potential (BPND = fND * (Bavail / KD)) values were calculated in the prefrontal cortex, striatum, and limbic regions using the simplified reference tissue model with cerebellar grey matter as the reference region. RESULTS: [11C]ABP688 BPND was significantly higher in men compared to women in the prefrontal cortex (p < 0.01), striatum (p < 0.001), and hippocampus (p < 0.05). Whole-brain BPND was 17% higher in men. BPND was not related to menstrual phase in women. CONCLUSIONS: Binding availability of mGlu5 receptors as measured by PET [11C]ABP688 is higher in healthy men than women. This likely represents a source of variability in [11C]ABP688 studies and could have relevance for sex differences in cognitive-behavioral functions and neuropsychiatric disorders.

Do stressful life events during pregnancy modify associations between phthalates and anogenital distance in newborns?

Anogenital distance (AGD) has been used as a marker of fetal androgen action to identify endocrine disrupting chemicals. A US study (TIDES) has reported that the association between some phthalates and reduced AGD in males was only apparent in sons of mothers reporting no stressful life events (SLEs) during pregnancy. The objective of the current study was to examine the potential modifying effect of SLEs and their subjective impact on associations between prenatal phthalates and AGD. First trimester urines from the MIREC Study were analysed for phthalate metabolites and AGD was measured in neonates. Post-delivery, the women answered questions on SLEs during the pregnancy. Women reporting 1 or more SLEs during pregnancy were considered a "higher stressor" group, whereas women reporting no SLEs or who reported a SLE that was perceived as not at all stressful were considered a "lower stressor" group. Multivariable linear regression models were fit stratified by stressor group. Maternal stressor, AGD and phthalates results were available for 153 females and 147 males. A summary measure of androgen-disrupting phthalates (Σ AD) was associated with significantly longer AGDs in females from the higher stressor group. These effect sizes were increased when the perceived impact was restricted to moderately or very much stressful. In males, all phthalates were associated with longer anopenile distance (APD), regardless of stressor group; however, higher Σ AD was associated with significantly longer APD in the lower stressor group. In contrast to the TIDES study, we did not observe shorter AGDs in male infants prenatally exposed to di-(2-ethylhexyl) phthalates, regardless of maternal stressor level. In conclusion, we were unable to replicate the findings of the TIDES study, but did find some evidence that prenatal SLEs may modify associations between phthalates and female AGD. Further research with other populations and measures of prenatal stress may shed more light on whether prenatal stress is an important effect modifier of associations between phthalates (or other chemicals) and anogenital distance.

Mesolimbic connectivity signatures of impulsivity and BMI in early adolescence.

Across age groups, differences in connectivity of the mesolimbic and the prefrontal cortex co-vary with trait impulsivity and sensation-seeking. Impulsivity and sensation-seeking are also known to increase during early adolescence as maturation of subcortical structures outpaces that of the prefrontal cortex. While an imbalance between the striatum and prefrontal cortex is considered a normal developmental process, higher levels of adolescent impulsivity and sensation-seeking are associated with an increased risk for diverse problems, including obesity. To determine how the relationship between sensation-seeking, impulsivity and body mass index (BMI) is related to shared neural correlates we measured their relationships with the connectivity of nuclei in the striatum and dopaminergic midbrain in young adolescents. Data were collected from 116 children between the ages of 12 and 14, and included resting state functional magnetic resonance imaging, personality measures from the Substance Use Risk Profile Scale, and BMI Z-score for age. The shared variance for the connectivity of regions of interest in the substantia nigra, ventral tegmental area, ventral striatum and sub-thalamic nucleus, personality measures and BMI Z-score for age, were analyzed using partial least squares correlation. This analysis identified a single significant striato-limbic network that was connected with the substantia nigra, ventral tegmental area and sub-thalamic nuclei (p = 0.002). Connectivity within this network which included the hippocampi, amygdalae, parahippocampal gyri and the regions of interest, correlated positively with impulsivity and BMI Z-score for age and negatively with sensation-seeking. Together, these findings emphasize that, in addition to the well-established role that frontostriatal circuits play in the development of adolescent personality traits, connectivity of limbic regions with the striatum and midbrain also impact impulsivity, sensation-seeking and BMI Z-score in adolescents.

The Interactive Effects of Parental Knowledge with Impulsivity and Sensation Seeking in Adolescent Substance Use.

This study examined whether interactions of parental knowledge of adolescent's whereabouts with impulsivity and sensation seeking in the prediction of adolescent substance use supported the diathesis-stress or differential susceptibility model in 230 15-year old adolescents (53% girls). Interactions between impulsivity and parental knowledge supported the diathesis-stress model with high impulsivity as a vulnerability factor: when impulsivity was higher, low levels of parental knowledge were associated with higher levels of substance use. Interactions between sensation seeking and parental knowledge supported differential susceptibility with low sensation seeking as a susceptibility factor; low parental knowledge was associated with higher substance use and high parental knowledge with lower substance use when sensation seeking was lower. Our results show that impulsivity and sensation seeking should be considered independently. Results support previous research suggesting that impulsivity in adolescence may act as a vulnerability factor and suggests that low sensation seeking may be a susceptibility factor.

Modelling vocabulary development among multilingual children prior to and following the transition to school entry.

Differences between monolingual and multilingual vocabulary development have been observed but few studies provide a longitudinal perspective on vocabulary development before and following school entry. This study compares vocabulary growth profiles of 106 multilingual children to 211 monolingual peers before and after school entry to examine whether: (1) school entry coincides with different rates of vocabulary growth compared to prior to school entry, (2) compared to monolingual peers, multilingual children show different vocabulary sizes or rates of vocabulary growth, (3) the age of onset of second-language acquisition for multilingual children is associated with vocabulary size or rate of vocabulary growth, and (4) the sociolinguistic context of the languages spoken by multilingual children is associated with vocabulary size or rate of vocabulary growth. Results showed increases in vocabulary size across time for all children, with a steeper increase prior to school entry. A significant difference between monolingual and multilingual children who speak a minority language was observed with regards to vocabulary size at school entry and vocabulary growth prior to school entry, but growth rate differences were no longer present following school entry. Taken together, results suggest that which languages children speak may matter more than being multilingual per se.