Smoking onset and the time-varying effects of self-efficacy, environmental smoking, and smoking-specific parenting by using discrete-time survival analysis

This study examined the timing of smoking onset during mid- or late adolescence and the time-varying effects of refusal self-efficacy, parental and sibling smoking behavior, smoking behavior of friends and best friend, and parental smoking-specific communication. We used data from five annual waves of the ‘Family and Health’ project. In total, 428 adolescents and their parents participated at baseline. Only never smokers were included at baseline (n = 272). A life table and Kaplan–Meier survival curve showed that 51% of all adolescents who did not smoke at baseline did not start smoking within 4 years. The risk for smoking onset during mid- or late adolescence is rather stable (hazard ratio between 16 and 19). Discrete-time survival analyses revealed that low refusal self-efficacy, high frequency of communication, and sibling smoking were associated with smoking onset one year later. No interaction effects were found. Conclusively, the findings revealed that refusal self-efficacy is an important predictor of smoking onset during mid- or late adolescence and is independent of smoking-specific communication and smoking behavior of parents, siblings, and (best) friend(s). Findings emphasize the importance of family prevention programs focusing on self-efficacy skills.     

Genetic and Environmental Influences on the Stability of Withdrawn Behavior in Children: A Longitudinal,Multi-informant Twin Study

We examined the contribution of genetic and environmental influences on the stability of withdrawn behavior (WB) in childhood using a longitudinal multiple rater twin design. Maternal and paternal ratings on the withdrawn subscale of the Child Behavior Checklist (CBCL) were obtained from 14,889 families when the twins were 3, 7, 10 and 12 years old. A longitudinal psychometric model was fitted to the data and the fit of transmission and common factor models were evaluated for each variance component. WB showed considerable stability throughout childhood, with correlation coefficients ranging from about .30 for the 9-year time interval to .65 for shorter time intervals. Individual differences in WB as observed by the mother and the father were found to be largely influenced by genetic effects at all four time points, in both boys (50–66%) and girls (38–64%). Shared environmental influences explained a small to modest proportion (0–24%) of the variance at all ages and were slightly more pronounced in girls. Non-shared environmental influences were of moderate importance to the variance and slightly increased with age, from 22–28% at age 3 to 35–41% at age 12 years. The stability of WB was largely explained by genetic effects, accounting for 74% of stability in boys and 65% in girls. Shared environmental effects explained 7% (boys) and 17% (girls) of the behavioral stability. Most shared environmental effects were common to both raters, suggesting little influence of rater bias in the assessment of WB. The shared environmental effects common to both raters were best described by a common factor model, indicating that these effects are stable and persistent throughout childhood. Non-shared environmental effects accounted for the remaining covariance over time. Edited by Hermine Maes.     

The Genetic and Environmental Etiology of Antisocial Behavior from Childhood to Emerging Adulthood

Previous research suggests that both genetic and environmental influences are important for antisocial behavior across the life span, even though the prevalence and incidence of antisocial behavior varies considerably across ages. However, little is known of how genetic and environmental effects influence the development of antisocial behavior. A total of 2,600 male and female twins from the population-based Swedish Twin Registry were included in the present study. Antisocial behavior was measured on four occasions, when twins were 8–9, 13–14, 16–17, and 19–20 years old. Longitudinal analyses of the data were conducted using structural equation modeling. The stability of antisocial behavior over time was explained by a common latent persistent antisocial behavior factor. A common genetic influence accounted for 67% of the total variance in this latent factor, the shared environment explained 26%, and the remaining 7% was due to the non-shared environment. Significant age-specific shared environmental factors were found at ages 13–14 years, suggesting that common experiences (e.g., peers) are important for antisocial behavior at this age. Results from this study show that genetic as well as shared environmental influences are important in antisocial behavior that persists from childhood to emerging adulthood.     

Physical fitness factors to predict male Olympic wrestling performance

To determine differences in maximal strength and muscle power output of the arm and leg extensor muscles, peak and mean power during a modified standing crank-arm Wingate test, running speed, muscle extensibility, and anthropometric markers between elite and amateurs wrestlers according to the weight classes system; 92 male wrestlers were assigned into 6 groups according to their body mass (light, middle and heavy weight) and their competitive level (elite and amateur): Light Weight (body mass ranged between 55 and 68 kg) in elite (LW_E, n = 18) and amateur (LW_A, n = 15) level; Middle Weight (body mass ranged between 68 and 84 kg) in elite (MW_E, n = 18) and amateur (MW_A, n = 19) level; and Heavy Weight (body mass ranged between 84 and 100 kg) in elite (HW_E, n = 10) and amateur (HW_A, n = 12) level. Elite wrestlers were older (8–12%), had more training experience (25–37%), fat-free mass (3–5%), maximal strength in absolute and relative terms (8–25%), muscle power (14–30%), mean and peak power during crank-arm Wingate testing in absolute and relative terms (13–22%), jumping height (8–17%) as well as grip (6–19%) and back strength (7–20%) compared to amateur wrestlers. However, no differences were observed between elite and amateur groups in height, body mass index, percentage of body fat, hamstring extensibility and running speed. The present results suggest that the higher absolute and relative values of maximal strength, muscle power, and anaerobic metabolism, explained in part by the differences in lean mass and neural activation patterns, will give elite wrestlers a clear advantage during the most frequently used techniques in Olympic wrestling.     

Depressive Symptoms and Alcohol Use are Genetically and Environmentally Correlated Across Adolescence

Depressive symptoms and alcohol use are frequently positively associated during adolescence. This study aimed to assess the heritability of each phenotype across adolescence; to assess potential shared liabilities; to examine changes in the nature of shared liabilities across adolescence; and to investigate potential causal relationships between depressive symptoms and alcohol use. We studied a longitudinally assessed sample of adolescent Finnish twins (N = 1,282) to test hypotheses about genetic and environmental influences on these phenotypes within and across ages, using data from assessments at ages 12, 14, and 17.5 years. The heritability of depressive symptoms is consistent across adolescence (~40–50%), with contributions from common and unique environmental factors. The heritability of alcohol use varies across time (a² = .25–.44), and age 14 alcohol use is heavily influenced by shared environmental factors. Genetic attenuation and innovation were observed across waves. Modest to moderate genetic (r_A = .26–.59) and environmental (r_C = .30–.63) correlations between phenotypes exist at all ages, but decrease over time. Tests for causal relationships between traits differed across ages and sexes. Intrapair MZ difference tests provided evidence for reciprocal causation in girls at ages 14 and 17.5. Formal causal models suggested significant causal relationships between the variables in both boys and girls. The association between depressive symptoms and alcohol use during adolescence is likely due to a combination of shared genetic and environmental influences and causal influences. These influences are also temporally dynamic, complicating efforts to understand factors contributing to the relationship between these outcomes.     

Genetic and Environmental Causes of Variation in Trait Resilience in Young People

The aim of this multi-informant twin study was to determine the relative role of genetic and environmental factors in explaining variation in trait resilience in adolescents. Participants were consenting families (N = 2,638 twins in 1,394 families), from seven national cohorts (age 12–18 years, both sexes) of monozygotic and dizygotic twins reared together. Questionnaire data on the adolescents’ Ego-resilience (ER89) was collected from mothers, fathers and twins, and analysed by means of multivariate genetic modelling. Variance in trait resilience was best represented in an ADE common pathways model with sex limitation. Variance in the latent psychometric resilience factor was largely explained by additive genetic factors (77% in boys, 70% in girls), with the remaining variance (23 and 30%) attributable to non-shared environmental factors. Additive genetic sources explained more than 50% of the informant specific variation in mothers and fathers scores. In twins, additive and non-additive genetic factors together explained 40% and non-shared environmental factor the remaining 60% of variation. In the mothers’ scores, the additive genetic effect was larger for boys than for girls. The non-additive genetic factor found in the twins’ self ratings was larger in boys than in girls. The remaining sex differences in the specific factors were small. Trait resilience is largely genetically determined. Estimates based on several informants rather than single informants approaches are recommended.     

Heritability and Longitudinal Stability of Schizotypal Traits During Adolescence

The study investigated the genetic and environmental etiology of schizotypal personality traits in a non-selected sample of adolescent twins, measured on two occasions between the ages of 11 and 16 years old. The 22-item Schizotypal Personality Questionnaire- Child version (SPQ-C) was found to be factorially similar to the adult version of this instrument, with three underlying factors (Cognitive-Perceptual, Interpersonal-Affective, and Disorganization). Each factor was heritable at age 11–13 years (h ² = 42–53%) and 14–16 years old (h ² = 38–57%). Additive genetic and unique environmental influences for these three dimensions of schizotypal personality acted in part through a single common latent factor, with additional genetic effects specific to both Interpersonal-Affective and Disorganization subscales at each occasion. The longitudinal correlation between the latent schizotypy factor was r = 0.58, and genetic influences explained most of the stability in this latent factor over time (81%). These longitudinal data demonstrate significant genetic variance in schizotypal traits, with moderate stability between early to middle adolescence. In addition to common influences between the two assessments, there were new genetic and non-shared environmental effects that played a role at the later assessment, indicating significant change in schizotypal traits and their etiologies throughout adolescence.     

Parenting Stress as a Mediator Between Childhood ADHD and Early Adult Female Outcomes

The purpose of this study is to examine the mediating role of parenting stress (both parental distress and stress due to dysfunctional interactions in the mother–daughter relationship [PSDI]) in the link between childhood attention-deficit/hyperactivity disorder (ADHD) status and several important young adult outcomes. The diverse sample comprised 140 girls with ADHD and 88 age- and ethnicity-matched comparisons, evaluated at ages 6–12 years and followed prospectively for five years (M age = 14.2) and 10 years (M age = 19.6). The PSDI experienced by a mother during her daughter's adolescence mediated the link between her daughter's childhood ADHD status and adult externalizing and internalizing symptoms. PSDI also mediated the link between ADHD status and young adult nonsuicidal self-injury and had an indirect effect in the relation between childhood ADHD and young adult depressive symptoms. The mediating role of PSDI with respect to internalizing symptoms and depressive symptoms remained in place even when covarying adolescent internalizing/depressive symptoms. Parenting stress, particularly related to maternal perceptions of dysfunctional interactions with adolescent daughters, serves as a key mediator in the association between childhood ADHD status and important domains of young adult functioning. Minimizing parenting stress and dysfunctional mother–daughter interactions during adolescence might reduce the risk of adverse adult outcomes for girls with ADHD.     

Parenting as a Moderator of the Effects of Maternal Depressive Symptoms on Preadolescent Adjustment

The purpose of this study was to examine whether parenting moderated the association between maternal depressive symptoms and initial levels and growth of preadolescent internalizing and externalizing symptoms. This study used a community sample of preadolescent children (N = 214; 8–12 years old at Time 1), measuring maternal depressive symptoms and parenting at Time 1, and preadolescent internalizing and externalizing symptoms at each year for 3 years. After modeling latent growth curves of internalizing and externalizing symptoms, growth factors were conditioned on maternal depressive symptoms, positive (acceptance and consistent discipline) and negative (rejection and physical punishment) parenting, and the interactions of depression and parenting. Maternal rejection moderated the relation of maternal depression with internalizing symptoms, such that high rejection exacerbated the effects of maternal depressive symptoms on initial levels of preadolescent internalizing problems. There were no significant interactions predicting externalizing problems. The findings highlight how specific parenting behaviors may alter the way in which maternal depressive symptoms confer risk for behavior problems.     

Aerobic fitness testing in 6- to 9-year-old children: reliability and validity of a modified Yo–Yo IR1 test and the Andersen test

This study analysed the reliability and validity of two intermittent running tests (the Yo–Yo IR1 test and the Andersen test) as tools for estimating VO_2max in children under the age of 10. Two groups, aged 6–7 years (grade 0, n = 18) and 8–9 years (grade 2, n = 16), carried out two repetitions of a modified Yo–Yo IR1 test (2 × 16 m) and the Andersen test, as well as an incremental treadmill test, to directly determine the VO_2max. No significant differences were observed in test–retest performance of the Yo–Yo IR1 test [693 ± 418 (±SD) and 670 ± 328 m, r ² = 0.79, CV = 19%, p > 0.05, n = 32) and the Andersen test (988 ± 77 and 989 ± 87 m, r ² = 0.86, CV = 3%, p > 0.05, n = 31). The Yo–Yo IR1 (r ² = 0.47, n = 31, p < 0.002) and Andersen test performance (r ² = 0.53, n = 32, p < 0.001) correlated with the VO_2max. Yo–Yo IR1 performance correlated with Andersen test performance (r ² = 0.74, n = 32, p < 0.0001). In conclusion, the Yo–Yo IR1 and the Andersen tests are reproducible and can be used as an indicator of aerobic fitness for 6- to 9-year-old children.     

Impact of the Interaction Between the 5HTTLPR Polymorphism and Maltreatment on Adolescent Depression. A Population-Based Study

Serotonin plays a central role in mood regulation and the development of depressive disorders. The present study investigated whether a functional polymorphism (5HTTLPR) of the serotonin transporter gene interacts with maltreatment in the prediction of depression. A cohort of 17–18 years old students (n = 1,482) anonymously completed the Survey of Adolescent Life and Health in Vestmanland 2006 and gave a saliva sample for DNA extraction. An association between maltreatment and adolescent depression was found independent of sex. When the whole population was analyzed, no main effect of 5HTTLPR in association with depression was found. When separated by sex, a significant main effect and a G × E interaction effect of the SS allele was found among girls. No gene main effect or G × E interaction effect was found among boys. The present study confirms previous findings of sex differences in interaction effects between the 5HTTLPR polymorphism and maltreatment in the prediction of adolescent depression. Edited by Peter McGuffin.     

Impact of Pregnancy and Vaginal Delivery on the Passive and Active Mechanics of the Rat Vagina

Remodeling of vaginal extracellular matrix and smooth muscle likely plays a critical role in reducing the risk of maternal injury during vaginal delivery by altering the mechanical properties to increase distension and reduce stress. Long-Evans rats were divided into five groups to examine the passive mechanical and active contractile properties throughout pregnancy and postpartum: virgin (n = 17), mid-pregnant (Day 14–16, n = 12), late-pregnant (Day 20–22, n = 14), immediate postpartum (0–2 h after delivery, n = 14), and 4 week postpartum (n = 15). Longitudinal sections of vaginal tissue were loaded to failure uniaxially for passive mechanical or active contractile properties were examined. For passive mechanics, the tangent modulus decreased 45% by mid-pregnancy and immediately postpartum (p < 0.001). The ultimate strain continuously increased up to 43% higher than virgin animals (p = 0.007) in the immediate postpartum group. For active mechanics, the maximal contractile force was 36–56% lower through immediate postpartum animals, and was significantly more sensitive to K⁺ throughout pregnancy and postpartum (p = 0.003). The changes observed in the passive and active properties of the rat vagina are consistent with what would be expected from a tissue that is remodeling to maximize its ability to distend at the time of vaginal delivery to facilitate passage of the fetus with minimal injury.     

Postnatal changes in the styloid process,vagina processus styloidei,and stylomastoid foramen in relation to the function of muscles originating from the styloid process

We investigated age-related changes in the styloid process in 88 skulls, aged from 5 months to 85 years of age. The osseous styloid process was not well developed in children. Its length increased significantly with age (from 2.3 mm in 11–20 age group to 16.3 mm in 61–85 group). In adolescent specimens (11–20 years of age), the median distance from the styloid process to the stylomastoid foramen was 0.7–0.8 mm, whereas in adult and old age specimens the two structures were completely adjacent or very close, usually less than 0.2 mm. The process was missing in 5% of the adult specimens. There was a statistically significant positive association between the length of the styloid process with age (r = 0.3210, 95% CI 0.0817–0.5254; P = 0.0097), whereas the distance from the styloid process to the stylomastoid foramen significantly decreased with age (r = −0.4518, 95% CI −0.6167 to −0.2490; P = 0.0001). Changes in the length and shape of the styloid process reflected altered function of the three muscles originating from the styloid process—m. stylopharyngeus, m. stylohyoideus and m. styloglossus. They have a common function of lifting the aerodigestive elements upward and backward, after the descent of the aerodigestive tract and final morphological differentiation of the vocal system during puberty. Relationship between altered muscle function and the morphology of the styloid process are important for understanding the clinical syndromes related to the styloid process, such as Eagle’s syndrome. Presented as a poster at the 78 Jahresversammlung 2007 der Deutschen Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e.V., Munich, 17–20 May 2007.     

Parental punitive discipline and children’s depressive symptoms: Associations with striatal volume

Although parental harshness has been consistently linked with increased depressive symptoms in youth, its associations with children's brain structure are not well understood. The striatum has been strongly implicated in depression in adolescents and adults. In this study, we investigated the associations among parental harsh discipline, striatal volume, and depressive symptoms in children. Participants were parents and their 5- to 9-year-old children (63% female; 29% African American; 47% Hispanic/Latino). Parents completed questionnaires about their parenting behaviors and children's depressive symptoms. Children participated in a high-resolution, T1-weighted MRI scan, and volumetric data for the caudate, putamen, and nucleus accumbens were extracted (n = 20 with both parenting and MRI data; n = 48 with both MRI and depressive symptom data). Findings indicated that more frequent parental harsh discipline was significantly associated with smaller dorsal striatal volume (caudate plus putamen). In addition, smaller dorsal striatal volume was significantly associated with increased depressive symptoms in children. These associations remained significant after accounting for child age, sex, whole brain volume, and parental depressive symptoms. These findings suggest that parental harsh discipline may be associated with children's striatal volume, which may in turn be associated with their level of depressive symptoms.     

Sudden cardiac death caused by coronary vasculitis

Coronary vasculitis is a rare and diagnostically challenging cause of sudden cardiac death (SCD). There are currently no large-scale series on this rare entity. A retrospective non-case–control observational study of SCD with coronary vasculitis referred to a tertiary cardiac pathology referral centre at the National Heart and Lung Institute at the Royal Brompton Hospital between 1996 and 2010 was completed. Ten cases of SCD with coronary artery vasculitis were retrieved from a database of 1,980 SCD cases (0.5%) with a 1:1 male/female ratio; median age was 39 years and range 15–71 years. Six deaths occurred in hospital following symptoms or cardiac arrest in the community; the remaining died at rest at home (n = 4). Appearances ranged from aneurysms of the coronary artery to occlusive lesions mimicking atheroma or masses imitating tumour. Types of vasculitis detected were: eosinophilic (n = 5), two associated with Churg–Strauss syndrome; lymphoplasmacytic vasculitis (n = 4); and idiopathic giant cell arteritis (n = 1). This study shows coronary vasculitis as a rare cause of SCD with a variable macroscopic and microscopic presentation that pathologists need to be aware of.     

Participation in extracurricular activities and emotional and behavioral adjustment in middle childhood in Spanish Boys and Girls

This study examined the concurrent relationship between participation in extracurricular activities and externalizing and internalizing problems and social school behavior in a Spanish community sample, separately for boys (n=439) and girls (n=428), enrolled in 2nd, 4th, or 6th grades. Weekly participation in extracurricular activities was related to better emotional and behavioral adjustment and social competence. Overall, the relations were low and different according to gender, type of activity, and informant. Better adjustment was more related to participation in sports activities in boys and to participation in nonsports activities in girls. Size effect was higher for girls and decreased for both boys and girls when parental education and parenting practices were considered. Findings supported previous results obtained in American adolescents. © 2010 Wiley Periodicals, Inc.     

Associations Between Marital Conflict and Adolescent Conflict Appraisals,Stress Physiology,and Mental Health

The goal of the current study was to examine conflict appraisals and diurnal cortisol production as mediators of the robust association between marital conflict and adolescent adjustment problems. Parents reported their marital conflict and were observed engaging in a marital conflict discussion; they also reported adolescent internalizing and externalizing behaviors. Adolescents (n = 105, 52% female, 10–17 years of age) appraised their parents’ marital conflict and reported their internalizing and externalizing behaviors. After the laboratory visit, adolescents provided four saliva samples on each of 2 consecutive days to assess diurnal cortisol production. More-negative marital conflict predicted more self-blame for parental conflict, which in turn predicted less robust decreases in cortisol across the day. Further, this flattened cortisol production pattern mediated the relationship between greater self-blame for parental conflict and adolescents’ elevated internalizing behaviors. Feeling responsible for parental conflict appears to be particularly damaging in terms of physiological regulation and adjustment, and may therefore be a particularly useful intervention target.     

No Associations Between Single Nucleotide Polymorphisms in Corticoid Receptor Genes and Heart Rate and Cortisol Responses to a Standardized Social Stress Test in Adolescents: The TRAILS Study

Previously, sequence variation in the glucocorticoid (GR) and mineralocorticoid (MR) receptor genes (NR3C1 and NR3C2, respectively) have been found to be associated with physiological stress responses to social stress tests in small samples of adult men and oral contraceptives (OC) using women. Associations between single nucleotide polymorphisms (SNPs) in the GR (23EK-rs6190, 9beta-rs6198, BclI-rs4142324) and the MR gene (I180V-rs5522 and -2G/C (rs2070951) with cortisol and heart rate responses to a performance-related social stress task (public speaking and mental arithmetic) were examined in a large sample (n = 553) of adolescents (15–17 years). To make comparisons with previous findings, associations were tested in boys (n = 277), free-cycling (FC) girls (n = 183) and OC users (n = 93). None of the previously reported associations in adults could be replicated in this large adolescent sample. Explanations for non-replication are discussed.     

A retrospective study of 230 consecutive patients hospitalized for presumed travel-related illness (2000–2006)

A good knowledge of morbidity profiles among ill-returned travelers is necessary in order to guide their management. We reviewed the medical charts of 230 patients hospitalized in one infectious diseases department in France for presumed travel-related illnesses. The male-to-female ratio was 1.6 and the median age was 33 years (interquartile range [IQR], 25–50). Most patients (70.9%) were returning from sub-Saharan Africa. The median duration of travel was 28 days (IQR, 15–60) and the median time from return of travel to hospitalization was 13 days (IQR, 7–21). Malaria was the most frequent diagnosis (49.1%), which was especially encountered in patients returning from sub-Saharan Africa (95.6%), without adequate chemoprophylaxis (78.2%). Imported diseases at risk of secondary transmission were also diagnosed, including pulmonary tuberculosis (n = 8), viral hepatitis (n = 8), typhoid fever (n = 6), human immunodeficiency virus (HIV) (six new diagnosis), non-typhoid salmonellosis (n = 5), severe acute respiratory syndrome, and Crimean-Congo hemorrhagic fever. This study underlines the need to maintain tropical expertise for infectious diseases physicians, even in Europe.     

Cortisol secretion moderates the association between mother–infant attachment at 17 months and child behavior at age 5 years

This study examined infant cortisol secretion as a moderator of the association between mother–infant attachment security at age 17 months and child behavior at age 5 years. A longitudinal community sample of 96 mother–child dyads participated in the strange situation procedure (SSP) at age 17 months. Cortisol was collected at baseline, and at 20 and 40 min post-SSP. Maternal reports of child behavior were collected at age 5 years. Results revealed that the associations between nonsecure mother–infant attachment and higher total, internalizing, and externalizing behavior were stronger for infants with high cortisol secretion, relative to infants with low cortisol secretion. The model of interaction differed depending on the outcome, with diathesis-stress explaining variance in total as well as internalizing behavior, and with differential susceptibility explaining variance in externalizing behavior. These findings augment our understanding of risk and resilience to the impact of the early rearing environment on later psychopathology.