Detrimental Psychological Outcomes Associated with Early Pubertal Timing in Adolescent Girls

Timing of puberty in boys and girls: Implications for population health

Puberty is marked by substantial increases and emerging sex differences in psychological disorders and risky behaviors. However, few studies have examined these effects beyond adolescence, and the previous literature has been dominated by samples of White girls. The current study examines the broadest known set of health sequelae related to traditional pubertal markers and peer-relative pubertal timing in a representative sample of 14,545 U.S. youth from the National Longitudinal Study of Adolescent to Adult Health.

Maturational timing was assessed by age at menarche for girls and physical development for boys (e.g., facial hair, voice change), and then categorized as early (1 SD below mean), on-time, or late (1 SD above mean) within-sex. Early and late peer-relative timing was assessed by a self-report of looking “much older” or “much younger” than one's peers. We examined psychological (depressive symptoms, antisocial behavior), behavioral (number of sex partners, drug use, physical activity, screen time, sleep hours), and physical health (self-reported health, BMI) outcomes during adolescence and young adulthood in a series of sex-stratified regression analyses using survey weights and a comprehensive set of sociodemographic covariates.

Results indicated that, overall, earlier pubertal timing (i.e., maturational timing and peer-relative timing) put both girls and boys at risk during adolescence, while later timing was protective. However, longitudinal models revealed mixed results. For instance, early maturational timing was associated with higher young adult BMI (girls: β = 0.139, p < .01; boys: β = 0.107, p < .01), but later timing for boys was associated with both risky (e.g., more screen time; β = 0.125, p < .05) and health promoting (e.g., more sleep; β = .296, p < .01) behaviors. Analysis of this holistic set of outcomes with sex differences in mind allows for more careful evidence-based recommendations for adolescent health promotion.

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Early or late puberty predicts health, but there is little longitudinal research.

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Perceived pubertal development relative to peers also predicts health outcomes.

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Links between pubertal timing and long-term health were more pervasive for girls.

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Adolescent psychological symptoms and health behaviors explain long-term links.

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Results point to the need for high-quality puberty education early in life.

Oral contraceptive use in adolescence predicts lasting vulnerability to depression in adulthood

BACKGROUND

Previous evidence suggests that use of oral contraceptives (OCs), especially during adolescence, may increase women's vulnerability to depression in the short term. Here, we investigate whether women who had first used OC in adolescence show an increased prevalence of depression in the long term.

METHODS

We examined 1,236 women in the United States National Health and Nutrition Examination Survey for whom information on depression and age at first OC use was publicly available. We compared women who reported first use of OCs in adolescence to women who had never used OCs and women who had first used OCs in adulthood on 1-year prevalence of major depressive disorder (MDD) assessed by trained interviewers.

RESULTS

Compared with women who had used OCs during adolescence, women who had never used OCs were less likely to meet the criteria for MDD within the past year in adulthood [odds ratio (OR) = 0.31, 95% CI = 0.16-0.60], and so were women who only started using OCs in adulthood (OR = 0.54, 95% CI = 0.30-0.95). Third factors that have previously been proposed to explain the relationship between OC use and depression risk such as age at sexual debut, and, importantly, current OC use, did not account for the results in propensity score analyses.

CONCLUSIONS

We show a long-term association between adolescent OC use and depression risk in adulthood regardless of current OC use. Our findings suggest that adolescence may be a sensitive period during which OC use could increase women's risk for depression, years after first exposure.

In Utero Exposure to Glucocorticoids and Pubertal Timing in Sons and Daughters

Early pubertal timing has been associated with adult diseases, and identifying preventable causes is of importance. In utero exposure to exogenous glucocorticoids, has been associated with changes in the reproductive hormonal axes in the children, which may influence pubertal timing. Exogenous glucocorticoids can be indicated for diseases such as asthma, allergy, skin diseases, as well as muscle and joint diseases. The aim was to explore the association between in utero exposure to glucocorticoids and pubertal timing in the children. This population-based study was conducted in the Puberty Cohort including 15,819 children, which is a sub-cohort of the Danish National Birth Cohort. Information on maternal glucocorticoid treatment was collected through interviews during pregnancy. Information on pubertal timing was obtained by questionnaires every 6 months throughout puberty, including Tanner Stages, axillary hair, acne, voice break, first ejaculation and menarche. The potential impact of confounding by indication was explored by stratifying on indication and treatment status. Overall, 6.8% of the children were exposed to glucocorticoids in utero. Exposure to glucocorticoids in utero was not associated with earlier puberty for neither boys nor girls with combined estimates of 0.4 months (95% CI: -1.5; 2.2) and -0.7 months (95% CI: -2.5; 1.2).

Smaller anterior subgenual cingulate volume mediates the effect of girls' early sexual maturation on negative psychobehavioral outcome

Early-maturing girls are relatively likely to experience compromised psychobehavioral outcomes. Some studies have explored the association between puberty and brain morphology in adolescents, while the results were non-specific for females or the method was a region-of-interest analysis. To our knowledge, no large-scale study has comprehensively explored the effects of pubertal timing on whole-brain volumetric development or the neuroanatomical substrates of the association in girls between pubertal timing and psychobehavioral outcomes. We collected structural magnetic resonance imaging (MRI) data of a subsample (N ​= ​203, mean age 11.6 years) from a large-scale population-based birth cohort. Tanner stage, a scale of physical maturation in adolescents, was rated almost simultaneously with MRI scan. The Strengths and Difficulties Questionnaire total difficulties (SDQ-TD) scores were rated by primary parents some duration after MRI scan (mean age 12.1 years). In each sex group, we examined brain regions associated with Tanner stage using whole-brain analysis controlling for chronological age, followed by an exploration of brain regions also associated with the SDQ-TD scores. We also performed mediation analyses. In girls, Tanner stage was significantly negatively correlated with gray matter volumes (GMVs) in the anterior/middle cingulate cortex (ACC/MCC), of which the subgenual ACC (sgACC) showed a negative correlation between GMVs and SDQ-TD scores. Smaller GMVs in the sgACC mediated the association between higher Tanner stages and higher SDQ-TD scores. We found no significant results in boys. Our results from a minimally biased, large-scale sample provide new insights into neuroanatomical correlates of the effect of pubertal timing on developmental psychological difficulties emerging in adolescence.

Sex Hormone Phenotypes in Young Girls and the Age at Pubertal Milestones

CONTEXT

The age of pubertal onset is influenced by many variables in young girls. Previous studies have not examined sex hormones longitudinally around the time of breast development and their relationship to pubertal onset.

OBJECTIVE

We sought to use an unbiased statistical approach to identify phenotypes of sex hormones in young girls and examine their relationship with pubertal milestones.

DESIGN AND SETTING

Longitudinal observational study.

PARTICIPANTS AND MAIN OUTCOME MEASURES

In 269 girls, serum concentrations of steroid sex hormones [estradiol (E2), estrone, testosterone, and dehydroepiandrosterone sulfate] were measured by HPLC-mass spectrometry at time points before, at, and after thelarche. Girls were classified into four hormone phenotypes using objective principal components and cluster analyses of longitudinal hormone data. The association between the identified phenotypes and age of pubertal milestones was estimated using Cox proportional hazards modeling.

RESULTS

Mean ages at thelarche, pubarche, and menarche were 9.02, 9.85, and 12.30 years, respectively. Girls with low levels of all four hormones, phenotype 3b, were youngest at thelarche (8.67 years); those in phenotype 2, with the highest E2 levels and E2 surge 6 months after thelarche, were youngest at menarche (11.87 years) with shortest pubertal tempo. When controlling for race, maternal age of menarche, caregiver education, and body mass, different phenotypes were associated with the age of pubertal events.

CONCLUSIONS

Hormone phenotypic clustering can identify clinically relevant subgroups with differing ages of thelarche, pubarche, and menarche. These findings may enhance the understanding of timing of pubertal milestones and risk of adult disease.

Foot Length Growth as a Novel Marker of Early Puberty

Foot growth is part of overall pubertal growth but its relation to other anthropometric and hormonal changes is unclear. Our objective was to determine how foot length changes relate to changes in other growth parameters (height and weight), Tanner stage, and serum hormones. Adolescents (n = 342) were recruited to a 3-year longitudinal cohort study, underwent annual anthropometric assessments (height, weight, and foot length), and provided self-rated Tanner staging. They also provided blood samples that were analyzed using liquid chromatography-tandem mass spectrometry for serum testosterone and estradiol and classified as pre-pubertal or pubertal based on circulating hormone levels. Average annual percent increase in foot length was greater for pre-pubertal adolescents compared with pubertal. Increased foot length was associated with increases in height, weight, Tanner stage, and serum hormones in males and pre-menarcheal females but not post-menarcheal females. Foot length offers a novel, noninvasive, cost-effective, and easily demonstrable marker of early pubertal changes.

Exploring the mediating and moderating roles of body-related concerns and social interactions on the association between early puberty and psychological distress in young adult women

OBJECTIVE

To explore the mechanisms through which early puberty is associated with psychological distress in women aged 18-25. This cross-sectional study aims to investigate whether body-related concerns and social interactions moderate or mediate this association.

METHODS

Participants were compared on measures evaluating psychological distress, body image dysphoria, bulimic symptomatology and negative intimacy with best friend according to three pubertal timing groups: (1) "very early" puberty (menarche at 9 years old or less), (2) "early" puberty (menarche at 10 years old), and (3) "on-time" puberty (menarche between 11 and 13 years old). Forward stepwise multiple regressions and multiple mediation analysis were successively performed to see whether body-related concerns and peer interactions mediate or moderate the relationship between premature puberty and psychological distress.

RESULTS

Controlling for age and ethnicity, results indicated (1) that women who began puberty "very early" had significantly higher levels of psychological distress than their "on-time" counterparts; (2) the association found between very early puberty and psychological distress was mediated by body image dysphoria and negative intimacy with best friend and was moderated by bulimic symptomatology. No mediational effect was found in women whose puberty was "early".

CONCLUSION

These findings highlight the importance of using more than one group of early pubertal timing and the role of body and intimacy concerns in the explanation of psychological distress in women. Intervention strategies addressing the increased risk of psychological distress in women who begin puberty very early should target their body image and ability to form intimate friendships.

Differential effects of internalizing behaviors on academic functioning for girls versus boys: An analysis of developmental cascades from elementary to high school

Youth's academic and emotional functioning are closely related, yet little is known about the timing and direction of relationships involving internalizing problems, which are characterized by over control of emotions, anxiety, and depression as well as multiple aspects of academic achievement. This study addresses these gaps using data from the Study of Early Child Care and Youth Development (N= 1,048) to examine the processes by which problems in one domain of functioning lead to problems in another, known as a “cascade effect.” Results of longitudinal structural equation modeling indicate (a) a direct and indirect negative cascade effect from girls’ internalizing problems to their school achievement in high school, (b) a positive contemporaneous association of 9th grade boys’ internalizing problems with their cognitive achievement; and (c) ways in which demographic characteristics and adolescent social and maturational processes account for variation in functioning yet do not alter the processes by which the emotional and academic functioning interact. Results are discussed with regard to identifiying adolescents’ internalizing problems, gender differences in the effects of internalizing problems on academic functioning, timing of evidence-based interventions, and implications for mental health promotion among girls.

Pubertal development mediates the association between family environment and brain structure and function in childhood

Psychosocial acceleration theory suggests that pubertal maturation is accelerated in response to adversity. In addition, suboptimal caregiving accelerates development of the amygdala-medial prefrontal cortex circuit. These findings may be related. Here, we assess whether associations between family environment and measures of the amygdala-medial prefrontal cortex circuit are mediated by pubertal development in more than 2000 9- and 10-year-old children from the Adolescent Brain Cognitive Development Study (http://dx.doi.org/10.15154/1412097). Using structural equation modeling, demographic, child-reported, and parent-reported data on family dynamics were compiled into a higher level family environment latent variable. Magnetic resonance imaging preprocessing and compilations were performed by the Adolescent Brain Cognitive Development Study's data analysis core. Anterior cingulate cortex (ACC) thickness, area, white matter fractional anisotropy, amygdala volume, and cingulo-opercular network-amygdala resting-state functional connectivity were assessed. For ACC cortical thickness and ACC fractional anisotropy, significant indirect effects indicated that a stressful family environment relates to more advanced pubertal stage and more mature brain structure. For cingulo-opercular network-amygdala functional connectivity, results indicated a trend in the expected direction. For ACC area, evidence for quadratic mediation by pubertal stage was found. Sex-stratified analyses suggest stronger results for girls. Despite small effect sizes, structural measures of circuits important for emotional behavior are associated with family environment and show initial evidence of accelerated pubertal development.

Systematic review and meta-analysis of the association between childhood physical activity and age at menarche

AIM

To systematically appraise and summarise published evidence on the association between childhood physical activity (PA) and subsequent age at menarche (AAM).

METHODS

We searched PubMed (1990-2018) for studies that reported the relationship between childhood PA and AAM. We performed tabular synthesis of population-based studies and a random-effects meta-analysis of results of athlete/nonathlete studies.

RESULTS

One randomised controlled trial was identified, in which an intervention to prevent obesity reduced the likelihood of menarche during the two-year study period (relative risk: 0.75, 95% CI: 0.66-0.87; n = 422 girls). One of five prospective cohort studies (total n = 4492) reported a significant association between self-reported PA duration and subsequent menarche timing. Four of five historical cohort studies (total n = 89 470) reported significant associations between recalled premenarcheal PA and later AAM. Meta-analysis across 12 athlete/nonathlete studies showed that menarche occurred 1.13 years later (95% CI: 0.80-1.47) in athletes compared to nonathletes.

CONCLUSION

These findings suggest that AAM is a behaviourally modifiable trait. However, the quality of reported population-based study evidence is low and estimation of the true relationship between childhood PA and AAM is likely confounded by concomitant changes in diet and lifestyle behaviours.

Parents of early-maturing girls die younger

According to the life-history theory, rates of sexual maturation have coevolved with mortality rates so that individuals who mature faster tend to die younger. We used two data sets, providing different markers for the speed of pubertal development to test whether rates of sexual maturation of women predict the age at death of their parents. In the data set of Estonian schoolgirls born between 1936 and 1961, the rate of breast development predicted lifespan of both mothers and fathers (irrespectively of their socio-economic position), so that parents of rapidly maturing girls died at younger age. This finding supports the view that fast maturation rates in humans have coevolved with short lifespans and that such trade-offs can be detected as intergenerational phenotypic correlations in modern populations. Menarcheal age of participants of Estonian Biobank (born between 1925 and 1996) did not predict the age of death of their mothers; however, it did predict survival of their fathers, but only in environment where the genetic variation is exposed (families where at least one parent had tertiary education). In such families (where girls also matured 0.2-0.4 years earlier than in poorly educated families), 1-year delay in daughter's menarche corresponded to 9% lower hazard of father's death. Heritability of menarcheal age was also highest in well-educated families. The latter findings are consistent with the idea that genetic differences in the rate of pubertal maturation may be expressed most clearly in well-off families because in such families, the contribution of environmental variance to total phenotypic variance in menarcheal age is smallest. Our findings suggest that with global improvement and equalization of growth conditions, reductions of environmental variation in the rate of maturation increasingly expose the genetic differences in menarcheal age to selection. Under such conditions, selection on menarcheal age has a potential to affect the evolution of lifespan.

The effects of different rearing conditions on sexual maturation and maternal care in heterozygous mineralocorticoid receptor knockout mice

Sexual and social development is affected by a complex interplay between genetic makeup and the early-life rearing environment. While many rodent studies focused primarily on the detrimental effects of early-life stress, human literature suggests that genetic susceptibility may not be restricted to negative environments; it may also enhance the beneficial effects of positive rearing conditions. To examine this interaction in a controlled setting, heterozygous mineralocorticoid receptor knockout (MR^+/-) mice and control litter mates were exposed to a limited nesting/bedding (LN, impoverished), standard nesting (SN, control) or communal nesting (CN, enriched) paradigm from postnatal day 2-9 (P2-P9). Offspring was monitored for puberty onset between P24-P36 and, in females, maternal care-giving (i.e. as F1) during adulthood, after which basal corticosterone was measured. Different home-cage environments resulted in profound differences in received maternal care and offspring body weight. In male offspring, LN resulted in delayed puberty onset that was mediated by body weight and unpredictability of maternal care received during early development. In female offspring, rearing condition did not significantly alter sexual maturation and had little effect on their own maternal care-giving behavior. Genotype did affect maternal care: female MR^+/- offspring exhibited a less active nursing style and upregulated fragmentation during adulthood, irrespective of early life conditions. Basal corticosterone levels were highest in MR^+/- mice with a background of LN. Overall, we found a gene-by-environment interaction with respect to basal corticosterone levels, but not for sexual maturation or maternal behavior.

Heightened HPA-axis stress reactivity and accelerated pubertal progression predicts depressive symptoms over 4-year follow up

Pubertal timing has been suggested as biological factors implicated in the onset of depression in girls. This study aims to examine the prospective association between accelerated pubertal progression with depressive symptoms, and to further explore the possible role of individual reactivity to social stress in this association. A total of 56 girls with early puberty timing (assessed through breast Tanner stage) and 56 age-matched normal breast development girls were recruited at Wave 1 (grade 3) and followed for 4 years biennially. Hypothalamic-pituitary-adrenal axis stress reactivity was indexed by four cortisol samples collected before, during and after the Groningen Social Stress Test (GSST) at Wave 1. Depressive symptoms were interviewed through Mood & Feeling Questionnaire (MFQ) at each wave. About 42.9% (24/56) from early pubertal timing group and 19.6% (11/56) from normal control group were found accelerated breast development during 4-year follow-up. Mixed effects linear models illustrated that among accelerated breast development girls, those with heightened stress reactivity is likely to have a 6.62 (95% CI, 1.14-12.11)-point higher MFQ scores, and 41.9% (95%CI: 25.2 to 58.6%) higher probability for depressive symptoms, compared with girls with persistent normal breast development and moderate stress reactivity. However, no similar effects were found in girls with accelerated breast development but attenuated stress reactivity. The finding suggests that heightened cortisol reactivity to social stress may represent a useful biomarker in identifying girls at greatest risk of development of depressive symptoms following accelerated pubertal progression.

Understanding the Role of Puberty in Structural and Functional Development of the Adolescent Brain

Over the past two decades, there has been a tremendous increase in our understanding of structural and functional brain development in adolescence. However, understanding the role of puberty in this process has received much less attention. This review examines this relationship by summarizing recent research studies where the role of puberty was investigated in relation to brain structure, connectivity, and task-related functional magnetic resonance imaging (fMRI). The studies together suggest that puberty may contribute to adolescent neural reorganization and maturational advancement, and sex differences also emerge in puberty. The current body of work shows some mixed results regarding impact and exact direction of pubertal influence. We discuss several limitations of current studies and propose future directions on how to move the field forward.

Next Steps in Puberty Research: Broadening the Lens Toward Understudied Populations

Decades of puberty research have yielded key scientific discoveries. Building on the field's rich history, we highlight four understudied populations: youth of color, boys, sexual minority youth, and gender minority youth. We explore why scientific study has been slow to evolve in these groups and propose paths forward for exciting new work. For ethnically racially diverse youth, we discuss the need to incorporate culture and context. For boys, we highlight methodological issues and challenges of mapping existing conceptual models onto boys. For sexual and gender minority youth, we discuss unique challenges during puberty and suggest ways to better capture their experiences. With an eye toward a new era, we make recommendations for next steps and underscore the importance of transdisciplinary research.

Alexithymic traits can explain the association between puberty and symptoms of depression and anxiety in adolescent females

Symptoms of internalizing disorders such as depression and anxiety increase in adolescence, especially in females. However, gender differences in depression and anxiety symptoms emerge only after puberty onset. Levels of alexithymia, characterized by difficulties identifying and describing one's emotions, are elevated in depression and anxiety, and fluctuate across adolescence in a gender-specific manner. This study investigated changes in alexithymia across adolescence, and explored the potential role of alexithymia in the development of depression and anxiety, separately for females and males. Accordingly, 140 adolescents aged 11 to 21 years (77 female) completed self-report measures of alexithymia, depression and anxiety, and pubertal development. For females alone, pubertal maturation was associated with alexithymic traits (specifically difficulties identifying and describing feelings), as well as symptoms of depression and anxiety. After accounting for alexithymia, the relationship between puberty and depression and anxiety was absent or reduced in females. Thus, alexithymic traits may have differential consequences for males and females, and possibly contribute towards increased depression and anxiety symptoms in females during adolescence. We propose that developmental changes in alexithymia should be considered when studying the onset and development of internalizing psychological disorders during adolescence.

Contextualizing pubertal development: The combination of sexual partners' age and girls' pubertal development confers risk for externalizing but not internalizing symptoms among girls in therapeutic day schools

OBJECTIVE

Early pubertal development is associated with negative health and mental health outcomes. Research on the influence of puberty on mental health underscores a need to examine the interplay between puberty and exposure to environmental risk. This study investigates a more rarely studied aspect of girls' environments - romantic relationships with boyfriends. Specifically, this study examined sexual partner age and the timing of girls' pubertal development in relation to externalizing and internalizing symptoms among female students attending therapeutic day schools in the United States, a population at elevated risk for negative mental health outcomes.

METHODS

A total of 121 13 to 19-year-old adolescent girls (Mean age = 15.4; SD = 1.5) reported on the relative age of their past 3 sexual partners, their age of pubertal onset, and mental health challenges via clinical assessments of externalizing and internalizing symptoms.

RESULTS

Forty-three percent of participants qualified for at least one mental health diagnosis. Earlier pubertal onset predicted greater internalizing symptoms, and this effect did not depend on the age of girls' sexual partners. However, early-developing girls who also reported having a sexual partner more than 2 years older than them were at increased risk for externalizing symptoms.

CONCLUSIONS

Findings underscore that sexual relationships are an important risk factor for early-developing girls already at risk for mental health problems. Early developing girls with older partners may experience stronger social pressure to stay in relationships that expose them to partner violence and delinquency-related pressure, which combine with interpersonal stress to predict externalizing symptoms.

Initiation of the Hypothalamic-Pituitary-Gonadal Axis in Young Girls Undergoing Central Precocious Puberty Exerts Remodeling Effects on the Prefrontal Cortex

Central precocious puberty (CPP) has been shown to exert significant effects on psychosocial development. These early puberty-related hormones and psychosocial functional changes are considered to be associated with specific brain development. However, the biological mechanisms underlying the sculpting of human brain architecture and modulation of psychosocial transformation by puberty-related hormonal maturation remain elusive, especially during the early phase of CPP. The current investigation aims to specify the brain regions in which early hormone-related maturation effects occur during CPP and their relationships with psychological functions. 65 young girls (aged 4.3-8.0 years) underwent structural imaging on a 3T MR system, completed psychological tests and performed the gonadotropin-releasing hormone (GnRH) stimulation test to identify hormonal manifestations of hypothalamic-pituitary-gonadal axis (HPG axis) activation. Based on the GnRH test, 28 young girls were identified with CPP, whereas the other 37 girls were identified with non-central precocious puberty (NCPP). Cortical parameters were calculated and compared between the two groups after adjusting for age, weight, and height. Brain regions showing group differences were extracted and correlated with serum hormone levels and psychological parameters. The CPP girls showed thinner cortices primarily in the right rostral middle frontal cortex. This morphological difference was positively correlated with stimulated estradiol (E2) levels. Further, higher E2 levels were significantly associated with higher hyperactivity scores. Premature HPG axis activation in CPP girls at an early stage appears to exert remodeling effects on brain anatomy, primarily in the prefrontal cortex, which may affect psychological development following the emergence of robust changes in sex hormones.

Risky sex behaviours among college students: The psychosocial profile

AIMS

Risky sex behaviours among college students are a growing public health concern. However, few studies have profiled these behaviours using a large range of psychosocial correlates.

METHODS

Participants were 6874 undergraduate and postgraduate students (64.7% female, age range 17-25 years, M = 20.43 years, SD = 1.86 years) drawn from 13 higher-level institutions in Ireland.

RESULTS

Regarding prevalence, 75% of the sample report that they have been, or are currently sexually active. Of this sexually active cohort (n = 5111), 27.2% report early sexual initiation, 29.5% report 5 or more lifetime sexual partners and 12.1% report 2 or more sexual partners in the past 3 months. In addition, 47.7% of students report inconsistent condom use and 39.5% report inconsistent use of other contraceptive methods in the past 3 months. Using multivariate logistic regression analyses, significant correlates of risky sex behaviour are identified across 5 groups of psychosocial predictors (demographic, sexuality and relationships, substance use, mental well-being and personal resources). Differences between males and females and between different sexual orientations are highlighted.

CONCLUSIONS

Suggestions are made for sexual education and intervention programs to specifically target subgroups of the student population.

Pubertal timing and callous-unemotional traits in girls: Associations across two samples from the UK and Cyprus

INTRODUCTION

Girls remain an understudied group when examining delinquency. Callous-unemotional traits are chief among personality traits that relate to delinquency. Some suggest, however, that girls who evince callous-unemotional traits delay their delinquent behavior until adolescence. This transitional period encompasses physical factors that relate to engagement in risky decision making, but we don't know how these factors relate to callous-unemotional traits. Early pubertal timing shows positive associations with delinquency; we tested if this was also the case for callous-unemotional traits.

METHODS

We tested associations among pubertal timing (i.e., maturity and menarche age), delinquency, and callous-unemotional traits within girls (ages 11-18 years) sampled from two European countries (UK and Cyprus). We also tested the interaction between callous-unemotional traits and pubertal timing in statistically predicting delinquency to test if associations between early puberty and delinquency were moderated by callous-unemotional traits.

RESULTS

Greater callous-unemotional traits were surprisingly negatively related to early pubertal timing. Those girls in the delayed menarche group had the highest level of callous-unemotional traits, higher than the typical and early menarche groups. Only callous-unemotional traits statistically predicted variance in delinquency and no moderation was evident.

CONCLUSIONS

The implications are that callous-unemotional traits and the transition to puberty may be particularly important for girls' adjustment in adolescence, particularly if menarche is delayed allowing girls to avoid punishment by capitalizing on their immaturity.

Pubertal Timing as a Transdiagnostic Risk for Psychopathology in Youth

Evidence suggests that early pubertal timing may operate as a transdiagnostic risk factor (i.e., shared across syndromes of psychopathology) for both genders. The current study examined associations between pubertal timing and dimensional psychopathology, structured across different levels of three organizational models: 1) DSM-based syndrome model, 2) traditional model of internalizing and externalizing factors, and 3) bifactor (p-factor) model, which includes a general psychopathology factor as well as internalizing- and externalizing- specific factors. For study analyses, 567 youth-parent pairs completed psychopathology measures when youth (55.5% female) were 13.58 (SD = 2.37, range = 9-17). Findings across all models revealed that early pubertal timing served as a transdiagnostic risk factor and also displayed some syndrome specific associations. Gender did not moderate any relationships between pubertal timing and psychopathology. Study findings reinforce the importance of examining risk across different levels of psychopathology conceptualization and analysis.

Body Image Dissatisfaction and the Adrenarchal Transition

BACKGROUND

Puberty marks a transition in risk for body image disturbance and disordered eating. Yet few studies have examined these symptoms across puberty and none have examined links with adrenarche, the earliest phase in the pubertal hormonal cascade.

METHOD

Levels of adrenal androgens (dehydroepiandrosterone, dehydroepiandrosterone sulphate, and testosterone) were measured in a population-based study of 8- to 9-year-old children (516 males and 621 females). Body dissatisfaction was measured using the Kids' Eating Disorder Scale Silhouettes. Covariates included body mass index, age, and socioeconomic status.

RESULTS

There were significant associations between adrenal androgen levels and greater body dissatisfaction in both males and females. Specifically, females with more advanced levels of dehydroepiandrosterone and testosterone relative to peers, and males with more advanced levels of testosterone relative to peers, reported greater body dissatisfaction. However, after adjusting for covariates, hormones levels were no longer associated with body dissatisfaction, and only higher body mass index had a clear association with body dissatisfaction.

CONCLUSIONS

The adrenarchal transition brings a heightened risk for body dissatisfaction. Whether this arises from the neuroendocrine effects of adrenal androgens or as a reaction to the greater body mass that accompanies adrenarche requires further exploration.

Outcomes of pubertal development in girls as a function of pubertal onset age

BACKGROUND

The relationship between pubertal onset and tempo and pubertal growth is controversial. We hypothesized that the age at onset of girls' puberty predicts pubertal tempo and the rate of pubertal progression.

METHODS

We analysed the data of 380 girls from the prospective Study of Early Child Care and Youth Development (SECCYD), who were recruited in the USA from 1991-2006 and followed from birth to age 15.5 years. We used the following indicators: thelarche age (Tanner stage B2), pubarche age (P2), menarche age (M), the age when breast (B5) and pubic hair (P5) became fully mature, pubertal growth, pubertal duration (time from B2 to B5), pubertal progression (time from B2 to M). We clustered the girls according to B2 age into early onset (EO;<9.4 years), intermediate (IO;9.4-10.5 years), late onset (LO;>10.5 years).

RESULTS

All indicators of pubertal onset and conclusion occurred earlier in the EOs than in the LO; yet, the differences in the age at main pubertal milestones lessened as puberty progressed: two years for B2; -1.4 years for M; - one year for B5. In EO, puberty was one year (average) longer than in LO. Although EO grew 7 cm (average) more than LO, their heights at B5 were comparable. There was a significant relationship between the thelarche age and puberty tempo (r=0.23, P<0.0001).

CONCLUSIONS

The study highlights the predictive nature of variation in the onset age of puberty on its progression and duration. These results are reassuring in this context and will add to clinicians' and parental understanding of the expected milestones of puberty.

Complex genetics of female fertility

Variation in reproductive lifespan and female fertility have implications for health, population size and ageing. Fertility declines well before general signs of menopause and is also adversely affected by common reproductive diseases, including polycystic ovarian syndrome (PCOS) and endometriosis. Understanding the factors that regulate the timing of puberty and menopause, and the relationships with fertility are important for individuals and for policy. Substantial genetic variation exists for common traits associated with reproductive lifespan and for common diseases influencing female fertility. Genetic studies have identified mutations in genes contributing to disorders of reproduction, and in the last ten years, genome-wide association studies (GWAS) have transformed our understanding of common genetic contributions to these complex traits and diseases. These studies have made great progress towards understanding the genetic factors contributing to variation in traits and diseases influencing female fertility. The data emerging from GWAS demonstrate the utility of genetics to explain epidemiological observations, revealing shared biological pathways linking puberty timing, fertility, reproductive ageing and health outcomes. Many variants implicate DNA damage/repair genes in variation in the age at menopause with implications for follicle health and ageing. In addition to the discovery of individual genes and pathways, the increasingly powerful studies on common genetic risk factors help interpret the underlying relationships and direction of causation in the regulation of reproductive lifespan, fertility and related traits.

Age at puberty and risk of asthma: A Mendelian randomisation study

BACKGROUND

Observational studies on pubertal timing and asthma, mainly performed in females, have provided conflicting results about a possible association of early puberty with higher risk of adult asthma, possibly due to residual confounding. To overcome issues of confounding, we used Mendelian randomisation (MR), i.e., genetic variants were used as instrumental variables to estimate causal effects of early puberty on post-pubertal asthma in both females and males.

METHODS AND FINDINGS

MR analyses were performed in UK Biobank on 243,316 women using 254 genetic variants for age at menarche, and on 192,067 men using 46 variants for age at voice breaking. Age at menarche, recorded in years, was categorised as early (<12), normal (12-14), or late (>14); age at voice breaking was recorded and analysed as early (younger than average), normal (about average age), or late (older than average). In females, we found evidence for a causal effect of pubertal timing on asthma, with an 8% increase in asthma risk for early menarche (odds ratio [OR] 1.08; 95% CI 1.04 to 1.12; p = 8.7 × 10(-5)) and an 8% decrease for late menarche (OR 0.92; 95% CI 0.89 to 0.97; p = 3.4 × 10(-4)), suggesting a continuous protective effect of increasing age at puberty. In males, we found very similar estimates of causal effects, although with wider confidence intervals (early voice breaking: OR 1.07; 95% CI 1.00 to 1.16; p = 0.06; late voice breaking: OR 0.93; 95% CI 0.87 to 0.99; p = 0.03). We detected only modest pleiotropy, and our findings showed robustness when different methods to account for pleiotropy were applied. BMI may either introduce pleiotropy or lie on the causal pathway; secondary analyses excluding variants associated with BMI yielded similar results to those of the main analyses. Our study relies on self-reported exposures and outcomes, which may have particularly affected the power of the analyses on age at voice breaking.

CONCLUSIONS

This large MR study provides evidence for a causal detrimental effect of early puberty on asthma, and does not support previous observational findings of a U-shaped relationship between pubertal timing and asthma. Common biological or psychological mechanisms associated with early puberty might explain the similarity of our results in females and males, but further research is needed to investigate this. Taken together with evidence for other detrimental effects of early puberty on health, our study emphasises the need to further investigate and address the causes of the secular shift towards earlier puberty observed worldwide.

Girls' pubertal development is associated with white matter microstructure in late adolescence

Patterns of pubertal maturation have been linked to vulnerability for emotion dysregulation disorders in girls, as well as white matter (WM) development, suggestive of a potential mechanism between pubertal maturation and emotional health. Because pubertal processes begin at varying ages (i.e., status, timing) and proceed at varying rates (i.e., tempo), identifying individual differences in the pubertal course associated with subsequent WM microstructure development may reveal clues about neurobiological mechanisms of girls' emotional well-being. In a prospective cohort study of 107 girls, we examined associations between pubertal status at age 9, pubertal timing and tempo from ages 9-15, and WM microstructure at age 19. Tract-based spatial statistics revealed that girls with more advanced pubertal status at age 9, specific to gonadal-related physical changes, had higher fractional anisotropy, and lower mean diffusivity (MD) and radial diffusivity in tracts relevant to cognitive control and emotion regulation (e.g., the superior longitudinal fasciculus, external capsule, and uncinate fasciculus). Additionally, girls with earlier pubertal timing showed lower MD in the left anterior cingulum bundle. Tempo was unrelated to WM measures. These findings implicate specific aspects of pubertal maturation in subsequent neural signatures, suggesting possible neuroendocrine mechanisms relevant to emotional development. Future work incorporating longitudinal neuroimaging in parallel with pubertal measures may contribute to the understanding of individual variation in pubertal course and WM development.

Malocclusion and maxillofacial characteristics of young girls having precocious puberty

AIM

This study aimed to evaluate the dentofacial characteristics and need for orthodontic treatment in young girls having precocious puberty (PP).

DESIGN

It was a cross-sectional study that included 39 girls, age ranging from 6 to 11 years old, with confirmed diagnosis of PP. The Dental Aesthetic Index (DAI) and the Index of Orthodontic Treatment Need (IOTN) were used to assess malocclusion and the need for orthodontic treatment, and cephalometric analysis was used for the diagnosis of facial growth abnormalities. Data analysis included descriptive statistics and one-sample t-test.

RESULTS

Findings revealed high prevalence (64.1%) of severe and very severe malocclusion (DAI grades 3-4), and 82.1% of cases were classified as having moderate to high treatment need (IOTN grades 3-4). All linear cephalometric measures and most of the angular parameters differed significantly from the reference values, indicating a tendency for Class II molar relationship. There was a high proportion of the sample outside the reference value limits, ranging from 79.5% of cases below the reference limits for facial height to 59.0% of cases above the limits for incisor-mandibular plane angle.

CONCLUSIONS

Results suggest that dental and craniofacial development may be associated with PP in young girls, which may be considered in the diagnosis and treatment decisions for orthopaedic/orthodontic intervention.

Gendered Mechanisms Underlie the Relation Between Pubertal Timing and Adult Depressive Symptoms

PURPOSE

Sex differences in depression emerge in adolescence, in concert with puberty. Off-time maturers, especially early-maturing girls, report more depressive symptoms than their same-sex peers. Recent evidence shows that these pubertal timing effects persist into adulthood, but the underlying mechanisms are unclear.

METHODS

Participants were 318 young adults (201 women, 117 men) who rated their depressive symptoms in the past 2 weeks and provided valid retrospective reports of their pubertal timing. Controlling for age, regression analyses were used to examine effects of sex, linear and quadratic pubertal timing, and their interaction on depressive symptoms. (Non)linear indirect effects analyses were used to identify psychological mechanisms (self-perceived masculinity, positive affect, and negative affect) underlying persisting effects, separately for men and women.

RESULTS

For young men, pubertal timing effects on depression were linear, with later maturers reporting more symptoms. Effects were partially explained by late maturers' low self-perceptions of masculinity and low positive affect. For young women, pubertal timing effects on depression were quadratic, with early and late maturers reporting more symptoms than on-time maturers. Effects were partially explained by off-time maturers' high negative affect.

CONCLUSIONS

Pubertal timing is related to adult depressive symptoms, but the nature of the link and the mechanisms underlying it differ for men and women. This increases understanding of the long-term consequences of gendered adolescent experiences and may have downstream implications for individualized prevention and intervention through gender-related individual differences that contribute to heterogeneity in depression etiology.

Early pubertal timing and adult adjustment outcomes: Persistence, attenuation, or accentuation?

Early pubertal timing is associated with internalizing and externalizing problems during adolescence. However, few studies explicitly test whether early puberty is especially problematic for those with pre-existing problems (i.e., accentuation) and little is known about whether the negative correlates of early pubertal timing persist past young adulthood. We address these questions using longitudinal data from up to 451 participants in the Iowa Youth and Families project (e.g., Ge, Conger, & Elder, 1996, 2001). We replicated and extended previous results reported for this sample during adolescence (e.g., early maturing boys and girls reported more substance use) and found some evidence for accentuation in adolescence for psychological distress and substance use. However, correlations between early puberty and adult outcomes assessed up to two decades later were largely indistinguishable from zero including attenuation effects. These results suggest that any negative correlates of early pubertal timing are attenuated by the fourth decade of life.

Perceived pubertal timing and borderline personality pathology in female adolescent inpatients

Borderline personality pathology typically onsets during adolescence. An important consideration in understanding adolescent psychopathology is pubertal development. Perceived pubertal timing is one facet of puberty that is especially relevant to adolescent psychopathology, especially when timing is perceived to be early. Despite links between early pubertal timing and core features of borderline personality disorder, and between early pubertal timing and disruptions in the interpersonal context, perceived pubertal timing has yet to be studied in relation to adolescent borderline pathology. This preliminary study aimed to test the association between perceived pubertal timing and borderline symptoms in adolescent girls, controlling for internalizing and externalizing pathology. Forty-two female adolescent inpatients (ages 12-15, Mage = 14.02, 81% White) completed measures of perceived pubertal development and borderline symptoms and a diagnostic interview. Results indicated that earlier perceived pubertal timing was uniquely associated with higher borderline symptoms even when internalizing and externalizing disorders were covaried.

Relationship between pubertal timing and chronic nonspecific pain in adolescent girls: the Young-HUNT3 study (2006-2008)

The aim of this study was to examine a possible relationship between early puberty and chronic nonspecific pain in 13- to 18-year-old girls. All adolescents in Nord-Trøndelag County, Norway, were invited to participate in the Young-HUNT3 study (2006-2008). Of the invited girls, 81% answered the questionnaire and of these 3982 were 13 to 18 years of age. Menarche and perceived physical maturation were used as exposure measures. Early menarche was defined as <12 years, normal menarche as ≥12 and <14 years, and late menarche as ≥14 years. Perceived physical maturation was divided into maturing earlier, the same or later than others of their own age. The main outcome measure was chronic nonspecific pain, defined as pain in at least one location not related to any known disease or injury, for at least once a week during the last 3 months. The median age at menarche was 13.2 years. Chronic nonspecific pain was more prevalent among girls with early menarche (68%, 95% CI: 64%-72%) compared to girls with either normal (55%, 95% CI: 53%-57%), late (50%, 95% CI: 46%-54%), or no menarche (35%, 95% CI: 29%-40%). The association persisted after adjusting for age, body mass index, socioeconomic factors, and anxiety and depression. A similar association was found between girls that perceived themselves as earlier physically matured than their peers and chronic nonspecific pain. Headache/migraine was the most common type of chronic nonspecific pain regardless of menarcheal age. In all reported locations, pain was more prevalent in the group with early menarche compared to normal or late menarche.

Age at menarche and adult body mass index: a Mendelian randomization study

BACKGROUND

Pubertal timing has psychological and physical sequelae. While observational studies have demonstrated an association between age at menarche and adult body mass index (BMI), confounding makes it difficult to infer causality.

METHODS

The Mendelian randomization (MR) technique is not limited by traditional confounding and was used to investigate the presence of a causal effect of age at menarche on adult BMI. MR uses genetic variants as instruments under the assumption that they act on BMI only through age at menarche (no pleiotropy). Using a two-sample MR approach, heterogeneity between the MR estimates from individual instruments was used as a proxy for pleiotropy, with sensitivity analyses performed if detected. Genetic instruments and estimates of their association with age at menarche were obtained from a genome-wide association meta-analysis on 182,416 women. The genetic effects on adult BMI were estimated using data on 80,465 women from the UK Biobank. The presence of a causal effect of age at menarche on adult BMI was further investigated using data on 70,692 women from the GIANT Consortium.

RESULTS

There was evidence of pleiotropy among instruments. Using the UK Biobank data, after removing instruments associated with childhood BMI that were likely exerting pleiotropy, fixed-effect meta-analysis across instruments demonstrated that a 1 year increase in age at menarche reduces adult BMI by 0.38 kg/m² (95% CI 0.25-0.51 kg/m²). However, evidence of pleiotropy remained. MR-Egger regression did not suggest directional bias, and similar estimates to the fixed-effect meta-analysis were obtained in sensitivity analyses when using a random-effect model, multivariable MR, MR-Egger regression, a weighted median estimator and a weighted mode-based estimator. The direction and significance of the causal effect were replicated using GIANT Consortium data.

CONCLUSION

MR provides evidence to support the hypothesis that earlier age at menarche causes higher adult BMI. Complex hormonal and psychological factors may be responsible.

Preterm birth and the timing of puberty: a systematic review

BACKGROUND

An estimated 11% of births occur preterm, and survival is improving. Early studies suggested an association between preterm birth and earlier puberty. Given the adverse outcomes associated with early puberty this could have significant public health implications. The objective of this review was to assess the timing of puberty after preterm birth.

METHODS

Pubmed, Embase, Popline, Global Health and Global Health Library were searched using terms relating to "premature birth", "menarche", "puberty" and "follow up studies". Inclusion criteria were a population consisting of pubertal or post-pubertal adolescents and adults; studies which defined preterm delivery in participants and compared outcomes to those after term delivery; and a quantitative assessment of pubertal onset. Assessment of risk of bias was conducted using principles from the Critical Appraisal Study Process.

RESULTS

Our search identified 1051 studies, of which 16 met the inclusion criteria. In females, 8 studies found no association between preterm birth and the timing of menarche. Five studies found earlier onset in preterm infants, 1 found later onset, and 1 showed both earlier and later menarche, depending on birth weight. The range of effect of studies showing earlier menarche was - 0.94 to -0.07 years in the preterm group, with a median of - 0.3 years. In males, 2 studies showed earlier onset of puberty in the preterm group, 5 showed no difference, and 1 showed later onset. Most studies did not present outcomes in the form of a mean with standard deviation, precluding a meta-analysis. There was insufficient data to address potential confounding factors.

CONCLUSIONS

The published evidence does not suggest that being born preterm leads to a significant acceleration in the onset of puberty. This should prove reassuring for public health purposes, and for clinicians counseling parents of infants born preterm.

Adolescent resilience to addiction: a social plasticity hypothesis

The prevalence of substance use disorders is highest during adolescence; however, many adolescents experience a natural resolution of their substance use by early adulthood, without any formal intervention. Something appears to be unique and adaptive about the adolescent brain. In this Review, we examine the roles of the social environment and neurocognitive development in adolescents' natural resilience to substance use disorders. At present, little is known about the neurocognitive mechanisms that underlie this adaptive phenomenon, since neurodevelopmental studies have mainly focused on the risk side of the substance use equation: escalation of substance use. To provide a framework for future studies, we put forth a social plasticity model that includes developmentally limited enhanced social attunement (ie, the need to harmonise with the social environment), affective processing, and brain plasticity, which underlie adolescents' capacity to learn from and adapt to their constantly evolving social environments.

Effects of harsh parenting and positive parenting practices on youth aggressive behavior: The moderating role of early pubertal timing

Prior research indicates that early pubertal timing is associated with aggressive behavior, particularly in the context of adversity as postulated in the contextual amplification hypothesis. However, few studies have examined harsh parenting as the context for the effect of early pubertal timing. Even fewer studies have tested the interactive effect of early pubertal timing and positive parenting on aggressive behavior. In this study, we tested the proposition that early pubertal timing, contrary to the general conception of it as a vulnerability, indexed susceptibility, and thus early maturing individuals were affected more by their environment in a "for better and for worse" manner. The sample consisted of 411 community-recruited youth aged 11-12 years (51% boys, 80% African Americans). Participants reported Tanner Stages of pubertal development, aggressive behavior and harsh parenting practice of their parents. Puberty scores were standardized with groups of the same age, sex, and ethnicity, and those that scored the top one-third were defined as early maturing individuals. Parents reported youth's aggressive behavior and their parenting practices towards the youth, including harsh parenting and positive parenting. Early pubertal timing significantly moderated the relationship between harsh/positive parenting and aggressive behavior. Specifically, harsh parenting was positively associated with aggressive behavior to a larger degree among early maturing individuals than among on-time/late-maturing individuals. Positive parenting was inversely associated with aggressive behavior but only among early maturing individuals. This study is the first to document support for early pubertal timing as susceptibility to the environmental influences in relation to aggressive behavior. Theoretical and intervention implications are discussed.

Reward Seeking and Cognitive Control: Using the Dual Systems Model to Predict Adolescent Sexual Behavior

Research has provided support for the dual systems model of adolescent risk taking, but the model has rarely been applied to sexual behavior. Using data from the NICHD SECCYD (N = 958; Mage = 15.07, SD = 0.18), this study examined the effects of cognitive control, reward seeking, and their interaction on sexual behavior. Results of structural equation models revealed that performance on behavioral tasks assessing reward seeking and cognitive control uniquely predicted sexual intercourse, but the interaction between them was not significant. For oral sex, only cognitive control was a significant predictor. The findings provide additional support for the dual systems model, and suggest that reward seeking and cognitive control make unique contributions to adolescent sexual behavior.

Age, sex, and gonadal hormones differently influence anxiety- and depression-related behavior during puberty in mice

Anxiety and depression symptoms increase dramatically during adolescence, with girls showing a steeper increase than boys after puberty onset. The timing of the onset of this sex bias led us to hypothesize that ovarian hormones contribute to depression and anxiety during puberty. In humans, it is difficult to disentangle direct effects of gonadal hormones from social and environmental factors that interact with pubertal development to influence mental health. To test the role of gonadal hormones in anxiety- and depression-related behavior during puberty, we manipulated gonadal hormones in mice while controlling social and environmental factors. Similar to humans, we find that mice show an increase in depression-related behavior from pre-pubertal to late-pubertal ages, but this increase is not dependent on gonadal hormones and does not differ between sexes. Anxiety-related behavior, however, is more complex during puberty, with differences that depend on sex, age, behavioral test, and hormonal status. Briefly, males castrated before puberty show greater anxiety-related behavior during late puberty compared to intact males, while pubertal females are unaffected by ovariectomy or hormone injections in all assays except the marble burying test. Despite this sex-specific effect of pubertal hormones on anxiety-related behavior, we find no sex differences in intact young adults, suggesting that males and females use separate mechanisms to converge on a similar behavioral phenotype. Our results are consistent with anxiolytic effects of testicular hormones during puberty in males but are not consistent with a causal role for ovarian hormones in increasing anxiety- and depression-related behavior during puberty in females.

Phthalate and bisphenol A exposure during in utero windows of susceptibility in relation to reproductive hormones and pubertal development in girls

BACKGROUND

Over the past several decades, the age of pubertal onset in girls has shifted downward worldwide. As early pubertal onset is associated with increased risky behavior and psychological issues during adolescence and cardiometabolic disease and cancer in adulthood, this is an important public health concern. Exposure to endocrine disrupting chemicals during critical windows of in utero development may play a role in this trend. Our objective was to investigate trimester-specific phthalate and BPA exposure in relation to pubertal development among girls in the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) birth cohort.

METHODS

We measured maternal urinary phthalate metabolites and BPA in samples collected during the first, second, and third trimesters of pregnancy. To assess reproductive development among their female children, we measured serum testosterone, estradiol, dehydroepiandrosterone sulfate (DHEA-S), inhibin B, and sex hormone-binding globulin (SHBG), and assessed sexual maturation, including Tanner staging for breast and pubic hair development and menarche status, at age 8-13 years (n = 120). We used linear and logistic regression to examine measures of trimester-specific in utero exposure as predictors of peripubertal hormone levels and pubertal onset, respectively. In secondary analyses, we evaluated estimated exposure at the midpoint of the first trimester and rates of change in exposure across pregnancy in relation to outcomes.

RESULTS

Several phthalate metabolites measured throughout in utero development were associated with higher serum testosterone concentrations, while a number of metabolites measured in the third trimester were associated with higher DHEA-S. For example, an interquartile range (IQR) increase in mean monoethyl phthalate (MEP) levels across pregnancy was associated with 44% higher peripubertal testosterone (95% CI: 13-83%), while an IQR increase in di-2-ethylhexyl phthalate metabolites (ΣDEHP) specifically in the third trimester was associated with 25% higher DHEA-S (95%CI: 4.7-47%). In IQR increase in mean mono-2-ethylhexyl phthalate (MEHP) levels across pregnancy was associated with lower odds of having a Tanner Stage >1 for breast development (OR = 0.32, 95%CI: 0.11-0.95), while MEHP in the third trimester was associated with higher odds of having a Tanner Stage >1 for pubic hair development (OR = 3.76, 95%CI: 1.1-12.8). Results from secondary analyses were consistent with findings from our main analysis.

CONCLUSION

These findings suggest that female reproductive development may be more vulnerable to the effects of phthalate or BPA exposure during specific critical periods of in utero development. This highlights the need for comprehensive characterizations of in utero exposure and consideration of windows of susceptibility in developmental epidemiological studies. Future research should consider repeated measures of in utero phthalate and BPA exposure within each trimester and across pregnancy.

Transdiagnostic psychiatric disorder risk associated with early age of menarche: A latent modeling approach

BACKGROUND

Earlier age of pubertal maturation in females is associated with increased risk for mental health problems in adolescence, compared with on-time or later maturation. However, most investigations of pubertal timing and mental health consider risk for individual disorders and fail to account for comorbidity. A latent-modeling approach using a large, nationally representative sample could better explain the transdiagnostic nature of the consequences of early-onset puberty.

METHODS

Data on age of menarche and mental disorders were drawn from a population-representative sample of adolescents (n=4925), ages 13-17. Confirmatory factor analysis was used to fit four latent disorder categories: distress, eating, and externalizing, and fear disorders. Timing of menarche included those with earlier (age≤10, age 11) and later age of onset (age 13, 14+), relative to those with average timing of menarche (age 12). Associations between timing of menarche and latent disorders were estimated in a structural equation model (SEM), adjusted for age, income, race, parent marital status, BMI, and childhood adversity.

RESULTS

The measurement model evidenced acceptable fit (CFI=0.91; RMSEA=0.02). Onset of menarche before age 11 was significantly associated with distress disorders (coefficient=0.096; p<0.0001), fear disorders (coefficient=0.09; p<0.0001), and externalizing disorders (coefficient=0.039; p=0.049) as compared to on-time or late menarche. No residual associations of early menarche with individual disorders over and above the latent disorders were observed.

CONCLUSION

The latent modeling approach illuminated meaningful transdiagnostic psychiatric associations with early timing of menarche. Biological processes initiated at puberty can influence cognitive and affective processes as well as social relationships for adolescents. Under developmentally normative conditions, these changes may be adaptive. However, for those out of sync with their peers, researchers and clinicians should recognize the potential for these processes to influence liability to a broad array of psychopathological consequences in adolescence.

Maternal Prepregnancy Weight and Children's Behavioral and Emotional Outcomes

INTRODUCTION

This study investigated associations between maternal prepregnancy BMI and child behaviors at ages 9-11 years and examine interaction by race and gender.

METHODS

The National Longitudinal Survey of Youth and the Children and Young Adults surveys are U.S.-based, ongoing longitudinal studies, initiated in 1979 and 1986, respectively. Mothers (n=2,952) reported pregnancy and child (n=5,660) developmental information at multiple time points. Child total, internalizing, and externalizing problems at ages 9-11 years were assessed using the Behavior Problems Index (BPI), collected biennially until 2012. Associations between prepregnancy BMI and child BPI outcomes were examined, as well as two- and three-way interactions by race and gender. Analyses were conducted in 2017.

RESULTS

Boys whose mothers had higher prepregnancy weights exhibited higher total BPI and externalizing scores at ages 9-11 years versus those with normal-weight mothers. Boys with severely obese mothers had higher total BPI (mean difference=7.99, 95% CI=3.53, 12.46) and externalizing (mean difference=5.77, 95% CI=1.50, 10.04) scores. Prepregnancy underweight was associated with boys' higher total BPI (mean difference=2.34, 95% CI=0.02, 4.66) and externalizing (mean difference=3.30, 95% CI=0.69, 5.91); these associations were not significant in sensitivity analyses. No associations emerged for girls or internalizing problems. Two-way interactions by race and three-way interactions by race and gender were not significant.

CONCLUSIONS

Maternal prepregnancy weight was associated with BPI level among boys. Boys with severely obese mothers exhibited markedly higher behavioral problems at ages 9-11 years versus those with normal-weight mothers, regardless of race. Maintaining healthy prepregnancy weight may be important for preventing boys' deleterious behavior outcomes in middle childhood.

Birth weight and prepubertal body size predict menarcheal age in India, Peru, and Vietnam

Evidence on the associations of birth weight and prepubertal nutritional status with menarcheal age for low- and middle-income countries is limited. We investigated these relationships using the Young Lives younger cohort for 2001 Indian, Peruvian, and Vietnamese girls born in 2001-2002. Girls were followed at approximately ages 1, 5, 8, and 12 years. Weibull survival models estimated hazards of earlier menarche on the basis of birth weight Z-scores (BWZ), and age-8 BMI-for-age Z-scores (BMIZ) and height-for-age Z-scores (HAZ). Estimates controlled for potential individual-, mother-, and household-level confounders and for changes in anthropometry between 1 and 8 years. In adjusted models, BWZ predicted later age at menarche (hazard ratio (HR) = 0.90, 95% CI: 0.83-0.97). Conversely, HAZ (HR = 1.66, 95% CI 1.5-1.83) and BMIZ at 8 years (HR = 1.28, 95% CI: 1.18-1.38) predicted earlier menarche. Changes in HAZ and BMIZ between 1 and 8 years were not associated with earlier menarche. Associations were consistent across countries, though with variation in estimated magnitudes. Maternal height and age were associated with later menarche. This evidence points to consistently robust and opposite associations of birth weight versus prepubertal attained height and body mass index with menarcheal age in three diverse settings with regard to nutrition, ethnicity, and socioeconomic status.

Genetics of depressive symptoms in adolescence

BACKGROUND

Despite many attempts to understand the genetic architecture of depression, little progress has been made. The majority of these studies, however, have been carried out in adults and do not account for the potential influence of development.

METHODS

The Avon Longitudinal Study of Parents and Children (ALSPAC) is a longitudinal pregnancy cohort which recruited participants between April 1991 and December 1992. Analyses were replicated in two independent European cohorts. Genome-wide complex trait analysis (GCTA) software was used to investigate SNP-heritability (h2SNP) of depression across adolescence, the role of puberty was investigated by stratifying these estimates according to pubertal onset. Genome-wide association studies were performed to identify genetic variants associated with depression at different stages of development.

RESULTS

Heritability was estimated between the ages of 11 and 18 with sample sizes ranging from 3289 to 5480. Heritability was low with an apparent peak was found at age 13 (h2 = 0.17, p = 0.006). Confidence intervals around these estimates suggest an upper-bound to h2SNP of around 30%. A variant located on chromosome 7 was found to be associated with depressive symptoms at age 13 in ALSPAC (rs138191010: β = 0.142, p = 2.51 × 10-8), although this was not replicated.

CONCLUSIONS

Although power is a potential limitation, the observed patterns provide interesting hypotheses surrounding the heritability of depression at different developmental stages. We found substantially lower estimates for depressive symptoms at age 11 (0.07) compared to those previously estimated in adults (0.21). We also found a peak in heritability at age 13. These findings suggest environmental factors are likely to be more important in the aetiology of depressive symptoms in early adolescence than in adulthood.

Age at Menarche and Time Spent in Education: A Mendelian Randomization Study

Menarche signifies the primary event in female puberty and is associated with changes in self-identity. It is not clear whether earlier puberty causes girls to spend less time in education. Observational studies on this topic are likely to be affected by confounding environmental factors. The Mendelian randomization (MR) approach addresses these issues by using genetic variants (such as single nucleotide polymorphisms, SNPs) as proxies for the risk factor of interest. We use this technique to explore whether there is a causal effect of age at menarche on time spent in education. Instruments and SNP-age at menarche estimates are identified from a Genome Wide Association Study (GWAS) meta-analysis of 182,416 women of European descent. The effects of instruments on time spent in education are estimated using a GWAS meta-analysis of 118,443 women performed by the Social Science Genetic Association Consortium (SSGAC). In our main analysis, we demonstrate a small but statistically significant causal effect of age at menarche on time spent in education: a 1 year increase in age at menarche is associated with 0.14 years (53 days) increase in time spent in education (95% CI 0.10–0.21 years, p = 3.5 × 10⁻⁸). The causal effect is confirmed in sensitivity analyses. In identifying this positive causal effect of age at menarche on time spent in education, we offer further insight into the social effects of puberty in girls.