Prenatal smoking and internalizing and externalizing problems in children studied from childhood to late adolescence

Right frontal cingulate cortex mediates the effect of prenatal complications on youth internalizing behaviors

Prenatal and perinatal complications represent well-known risk factors for the future development of psychiatric disorders. Such influence might become manifested during childhood and adolescence, as key periods for brain and behavioral changes. Internalizing and externalizing behaviors in adolescence have been associated with the risk of psychiatric onset later in life. Both brain morphology and behavior seem to be affected by obstetric complications, but a clear link among these three aspects is missing. Here, we aimed at analyzing the association between prenatal and perinatal complications, behavioral issues, and brain volumes in a group of children and adolescents. Eighty-two children and adolescents with emotional-behavioral problems underwent clinical and 3 T brain magnetic resonance imaging (MRI) assessments. The former included information on behavior, through the Child Behavior Checklist/6-18 (CBCL/6-18), and on the occurrence of obstetric complications. The relationships between clinical and gray matter volume (GMV) measures were investigated through multiple generalized linear models and mediation models. We found a mutual link between prenatal complications, GMV alterations in the frontal gyrus, and withdrawn problems. Specifically, complications during pregnancy were associated with higher CBCL/6-18 withdrawn scores and GMV reductions in the right superior frontal gyrus and anterior cingulate cortex. Finally, a mediation effect of these GMV measures on the association between prenatal complications and the withdrawn dimension was identified. Our findings suggest a key role of obstetric complications in affecting brain structure and behavior. For the first time, a mediator role of frontal GMV in the relationship between prenatal complications and internalizing symptoms was suggested. Once replicated on independent cohorts, this evidence will have relevant implications for planning preventive interventions.

Utility of the Zebrafish Model for Studying Neuronal and Behavioral Disturbances Induced by Embryonic Exposure to Alcohol, Nicotine, and Cannabis

It is estimated that 5% of pregnant women consume drugs of abuse during pregnancy. Clinical research suggests that intake of drugs during pregnancy, such as alcohol, nicotine and cannabis, disturbs the development of neuronal systems in the offspring, in association with behavioral disturbances early in life and an increased risk of developing drug use disorders. After briefly summarizing evidence in rodents, this review focuses on the zebrafish model and its inherent advantages for studying the effects of embryonic exposure to drugs of abuse on behavioral and neuronal development, with an emphasis on neuropeptides known to promote drug-related behaviors. In addition to stimulating the expression and density of peptide neurons, as in rodents, zebrafish studies demonstrate that embryonic drug exposure has marked effects on the migration, morphology, projections, anatomical location, and peptide co-expression of these neurons. We also describe studies using advanced methodologies that can be applied in vivo in zebrafish: first, to demonstrate a causal relationship between the drug-induced neuronal and behavioral disturbances and second, to discover underlying molecular mechanisms that mediate these effects. The zebrafish model has great potential for providing important information regarding the development of novel and efficacious therapies for ameliorating the effects of early drug exposure.

Maternal adherence to healthy lifestyle and risk of depressive symptoms in the offspring: mediation by offspring lifestyle

BACKGROUND

Adherence to healthy lifestyles can be beneficial for depression among adults, but the intergenerational impact of maternal healthy lifestyles on offspring depressive symptoms is unknown.

METHODS

In total, 10 368 mothers in Nurses' Health Study II and 13 478 offspring in the Growing Up Today Study were paired. Maternal and offspring healthy lifestyles were defined as a composite score including a healthy diet, normal body mass index (BMI), never-smoking, light-to-moderate consumption of alcohol, and regular moderate-to-vigorous physical activity. Maternal lifestyles were assessed during their offspring's childhood. Offspring depressive symptoms were repeatedly assessed five times using the Center for Epidemiological Studies Depression Scale-10 (CESD-10); the offspring were between the ages of 14 and 30 when the first CESD-10 was assessed. Covariates included maternal variables (age at baseline, race/ethnicity, antidepressant use, pregnancy complications, etc.) and offspring age and sex.

RESULTS

Children of mothers with the healthiest lifestyle had significantly fewer depressive symptoms (a 0.30 lower CESD-10 score, 95% confidence interval (CI) 0.09-0.50) in comparison with children of mothers with the least healthy lifestyle. The association was only found significant in female offspring but not in males. For individual maternal lifestyle factors, a normal BMI, never-smoking, and adherence to regular physical activity were independently associated with fewer depressive symptoms among the offspring. The association between maternal healthy lifestyles and offspring depressive symptoms was mediated by offspring's healthy lifestyles (mediation effect: 53.2%, 95% CI 15.8-87.3).

CONCLUSIONS

Our finding indicates the potential mechanism of intergenerational transmission of healthy lifestyles to reduce the risk of depressive symptoms in offspring.

Joint Effects of Indoor Air Pollution and Maternal Psychosocial Factors During Pregnancy on Trajectories of Early Childhood Psychopathology

Background

Prenatal indoor air pollution and maternal psychosocial factors have been associated with adverse psychopathology. We used environmental exposure mixture methodology to investigate joint effects of both exposure classes on child behavior trajectories.

Methods

For 360 children from the South African Drakenstein Child Health Study, we created trajectories of Child Behavior Checklist scores (24, 42, 60 months) using latent class linear mixed effects models. Indoor air pollutants and psychosocial factors were measured during pregnancy (2 nd trimester). After adjusting for confounding, single-exposure effects (per natural log-1 unit increase) were assessed using polytomous logistic regression models; joint effects using self-organizing maps (SOM), and principal component (PC) analysis.

Results

High externalizing trajectory was associated with increased particulate matter (PM 10 ) exposure (OR [95%-CI]: 1.25 [1.01,1.55]) and SOM exposure profile most associated with smoking (2.67 [1.14,6.27]). Medium internalizing trajectory was associated with increased emotional intimate partner violence (2.66 [1.17,5.57]), increasing trajectory with increased benzene (1.24 [1.02,1.51]) and toluene (1.21 [1.02,1.44]) and the PC most correlated with benzene and toluene (1.25 [1.02, 1.54]).

Conclusions

Prenatal exposure to environmental pollutants and psychosocial factors was associated with internalizing and externalizing child behavior trajectories. Understanding joint effects of adverse exposure mixtures will facilitate targeted interventions to prevent childhood psychopathology.

The Influence of Parental Mindfulness on Preschool Child Behavior Problems: A Chain-Mediated Model Analysis

This study aimed to examine the associations between parental mindfulness and preschool child behavior problems and to investigate the mediating role of marital satisfaction and coparenting in the relationship between mindfulness and preschool child behavior problems. This was a cross-sectional study in which general sociodemographic data were obtained from 3448 parents of children in grades junior to senior of kindergarten who were assessed using instruments such as the Mindful Attention Awareness Scale (MAAS), the Strengths and Difficulties Questionnaire (SDQ), the ENRICH Marital Satisfaction Scale (TEMSS), and the Parents' Perceptions of the Coparenting Relationship Questionnaire (PPCR). (1) Mindfulness, preschool child behavior problems, marital satisfaction, and coparenting were significantly correlated with each other, where mindfulness was positively correlated with marital satisfaction and coparenting and significantly negatively correlated with preschool child behavior problems. (2) Mindfulness negatively predicted preschool children's problem behaviors. (3) Marital satisfaction independently mediated the relationship between mindfulness and preschool child behavior problems. (4) Coparenting also independently mediated the relationship between mindfulness and preschool child behavior problems. (5) Marital satisfaction and coparenting play a chain-mediating role between mindfulness and preschool children's problem behaviors. Mindfulness predicted preschool child behavior problems, with marital satisfaction and coparenting as mediators.

Maternal smoking during pregnancy, offspring smoking, adverse childhood events, and risk of major depression: a sibling design study

BACKGROUND

Evidence of a biologically plausible association between maternal smoking during pregnancy (MSP) and the risk of depression is discounted by null findings from two sibling studies. However, valid causal inference from sibling studies is subject to challenges inherent to human studies of MSP and biases particular to this design. We addressed these challenges in the first sibling study of MSP and depression conducted among adults past the peak age for the onset of depression, utilizing a prospectively collected and biologically validated measure of MSP and accounting for non-shared as well as mediating factors.

METHODS

We fit GEE binomial regression models to correct for dependence in the risk of depression across pregnancies of the same mother. We also fit marginal structural models (MSM) to estimate the controlled direct effect of MSP on depression that is not mediated by the offspring's smoking status. Both models allow the estimation of within- and between-sibling risk ratios.

RESULTS

The adjusted within-sibling risk ratios (RR_W) from both models (GEE: RR_W = 1.97, CI 1.16-3.32; MSM: RR_W = 2.08, CI 1.04-4.17) evinced an independent association between MSP and risk of depression. The overall effects from a standard model evinced lower associations (GEE: RR_T = 1.12, CI 0.98-1.28; MSM: RR_T = 1.18, CI 1.01-1.37).

CONCLUSIONS

Based on within-sibling information free of unmeasured shared confounders and accounting for a range of unshared factors, we found an effect of MSP on the offspring's risk of depression. Our findings, should they be replicated in future studies, highlight the importance of considering challenges inherent to human studies of MSP and affective disorders.

Prenatal determinants of depressive symptoms in childhood: Evidence from Growing Up in New Zealand

BACKGROUND

Young people who experience depression are at an increased risk of adverse psychosocial and developmental outcomes that can persist over the lifecourse. Identifying maternal prenatal risk factors that may contribute to childhood depressive symptoms can be useful when considering mental health intervention.

METHODS

The current study included 3,925 children from the Growing Up in New Zealand (GUiNZ) study who had complete data for self-reported depressive symptoms and mothers' antenatal information. Depressive symptoms were measured at age 8 using the Centre for Epidemiological Studies Depression Scale for Children (CESD-10) short form questionnaire. Hierarchical linear regression was used to determine the relationship between prenatal factors and depressive symptoms at age 8.

RESULTS

When controlling for sociodemographic characteristics, our hierarchical linear regression revealed that the most significant maternal prenatal predictors of high depressive symptoms at age 8 were maternal perceived stress, smoking during pregnancy, body mass index (BMI) in the overweight/obese range, and paracetamol intake.

LIMITATIONS

One limitation with the current study was a reduction in the sample due to attrition. This may have affected our statistical power, reflected in our modest effect sizes. The sample remained both socioeconomically and ethnically diverse, however our results should be interpreted with respect to the sample and not the whole New Zealand population.

CONCLUSIONS

A combination of maternal mental health and lifestyle factors contribute to depressive symptoms for children, possibly through foetal programming. Our results emphasise the importance of mental and physical health support for expectant mothers.

Prenatal tobacco and alcohol exposures and the risk of anxiety symptoms in young adulthood: A population-based cohort study

BACKGROUND

Epidemiological studies have linked prenatal tobacco and alcohol exposures to internalizing behaviours in children and adolescents with inconsistent findings. Dearth of epidemiological studies have investigated the associations with the risk of experiencing symptoms of anxiety in young adulthood.

METHODS

Study participants (N = 1190) were from the Raine Study, a population-based prospective birth cohort based in Perth, Western Australia. Data on prenatal tobacco and alcohol exposures were available for the first and third trimesters of pregnancy. Experiencing symptoms of anxiety in young adulthood at age 20 years was measured by a short form of the Depression Anxiety Stress Scale (DASS 21). Relative risk (RR) of experiencing symptoms of anxiety in young adulthood for prenatal tobacco and alcohol exposures were estimated with log binomial regression.

RESULTS

After adjusting for potential confounders, we observed increased risks of experiencing symptoms of anxiety in young adults exposed to prenatal tobacco in the first trimester [RR = 1.52, 95% CI: 1.12-2.06, p-value < 0.01] and third trimester [RR = 1.53, 95% CI: 1.10-2.13, p-value  = 0.02]. However, we found insufficient statistical evidence for an association between first trimester [RR = 1.01, 95% CI: 0.76-1.22, p-value = 0.90] and third trimester [RR = 1.03, 95% CI: 0.80-1.34, p-value = 0.91] prenatal exposure to alcohol and the risk of experiencing symptoms of anxiety in young adults. There was a dose response association between prenatal tobacco exposure and increasing anxiety symptoms in offspring.

CONCLUSION

The findings of this study suggest that an association between prenatal tobacco exposure and risk of anxiety symptoms remains apparent into young adulthood.

Fluoride exposure during early adolescence and its association with internalizing symptoms

BACKGROUND

Early, chronic, low-level fluoride exposure has been linked to attention-deficit hyperactivity disorder (ADHD) and learning deficits in children. Rodent studies suggest a link between fluoride exposure and internalizing behaviors. No human studies have examined the impact of fluoride on internalizing behaviors during adolescence.

OBJECTIVE

Evaluate the relationship between urinary fluoride and early adolescent internalizing symptoms in the Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS).

METHODS

Participants in CCAAPS provided non-fasting spot urine samples at age 12 years (n = 286). Urine samples were analyzed using a microdiffusion method to determine childhood urinary fluoride (CUF) concentrations and were log-transformed for analyses. Caregivers of CCAAPS participants completed the Behavior Assessment System for Children-2 (BASC-2) at the age 12 study visit to assess internalizing symptoms (e.g., anxiety, depression, somatization), and a composite score of the three domains; T-scores ≥ 60 were used to identify adolescents in a clinically "at-risk" range. Race, age of the adolescent, household income, maternal age at birth, caregiver depression, caregiver-child relationships, and age 12-year serum cotinine concentrations were considered covariates in regression models. Sex-specific effects of fluoride exposures were investigated through the inclusion of interaction terms.

RESULTS

Higher CUF concentrations were significantly associated with increased somatization (β = 3.64, 95% CI 0.49, 6.81) and internalizing composite T-scores in a clinically "at-risk" range (OR = 2.9, 95% CI 1.24, 6.9). Compared to females, males with higher CUF concentrations had more internalizing (pinteraction = 0.04) and somatization symptoms (pinteraction = 0.02) and were nearly seven times more likely to exhibit "at-risk" internalizing symptomology. CUF concentrations were not significantly associated with depression or anxiety symptoms.

CONCLUSIONS

This is the first study to link fluoride exposure and internalizing symptoms, specifically somatization. Somatization represents an interface of physical and psychological health. Continued follow-up will help shed light on the sex-specific relationship between fluoride and mental health and the role of somatization.

Maternal smoking during pregnancy and children's mental health at age 22 years: Results of a birth cohort study

BACKGROUND

Early exposures such as maternal smoking can be associated mental disorders. We aimed to analyze the association between maternal smoking during pregnancy (MSDP), generalized anxiety disorder (GAD), and depression in the 1993 birth cohort (Pelotas, Brazil).

METHODS

Data on maternal smoking were collected in the perinatal study, while information on GAD and depression was collected at age 22 years using the Mini International Neuropsychiatric Interview (MINI). Information on maternal mental health, the mediator, was collected at the 11-year follow-up. Simple and multiple logistic regressions were used to assess the association between exposure, outcomes, and analysis of negative controls.

RESULTS

3,781 participants presented complete data. The incidence of GAD was 10.4%, depression 2.9%, and smoking during pregnancy 32.6%. The children of mothers who smoked had a 45% higher chance of developing GAD at age 22 years (OR 1.45; 95%CI 1.18; 1.80) and 75% higher chance of depression (OR 1.75; 95%CI 1.18; 2.59). Also, the higher the number of cigarettes smoked. the higher was the chance for the development of GAD. Paternal smoking was not associated with the outcomes. The mother's mental health accounted for 18.2% of the association between maternal smoking and GAD, and for 13.4% for maternal smoking and depression.

LIMITATIONS

Data for smoking during pregnancy were collected through a self-report. Residual confusion due to important variables cannot be ruled out.

CONCLUSIONS

MSDP was associated with the mental health of children in early adulthood. However, a small part of the effect found was mediated by the mother's mental health.

Maternal smoking during pregnancy and offspring psychiatric disorder: a longitudinal birth cohort study

BACKGROUND

There is evidence that prenatal stress and smoking during pregnancy both independently increase the risk of offspring psychopathology. Here we examine whether increased levels of self-reported stress is associated with increased smoking in a population of pregnant women, and whether prenatal smoking is associated with offspring psychiatric diagnoses independent of prenatal stress exposure.

METHOD

Using a longitudinal birth cohort, we used ordered logistic regressions to examine associations between maternal stress and smoking during pregnancy. We then used logistic regression analyses to examine associations between prenatal smoking and later offspring psychiatric disorders.

RESULTS

A dose-response relationship was found between maternally reported stress and smoking during pregnancy. Pregnant women reporting severe stress were more likely to smoke compared to both the moderate stress and no stress groups, and those reporting moderate stress were significantly more likely to smoke compared to the no stress group. Smoking more than 5 cigarettes daily during pregnancy increased the risk of offspring personality disorder (OR 3.08, 95% CI 1.60-5.94) as well as developing any Axis 1 psychiatric disorder, inclusive of mood, anxiety and psychotic disorders (OR 1.45, 95% CI 1.04-2.04). After adjusting for parental psychiatric history and maternal self-reported stress during pregnancy, associations between smoking more than 5 cigarettes daily when pregnancy and offspring personality (OR 2.58 95% CI 1.32-5.06) disorder remained.

CONCLUSION

Exposure to cigarette smoking during gestation could impact a child's mental health. Smoking during pregnancy is a prime target for preventative interventions as unlike most other environmental risk factors, it is very amenable to change.

Maternal and child genetic liability for smoking and caffeine consumption and child mental health: an intergenerational genetic risk score analysis in the ALSPAC cohort

BACKGROUND AND AIMS

Previous studies suggest an association between maternal tobacco and caffeine consumption during and outside of pregnancy and offspring mental health. We aimed to separate effects of the maternal environment (intrauterine or postnatal) from pleiotropic genetic effects.

DESIGN

Secondary analysis of a longitudinal study. We (i) validated smoking and caffeine genetic risk scores (GRS) derived from published genome-wide association study (GWAS) for use during pregnancy, (ii) compared estimated effects of maternal and offspring GRS on childhood mental health outcomes and (iii) tested associations between maternal and offspring GRS on their respective outcomes.

SETTING

We used data from a longitudinal birth cohort study from England, the Avon Longitudinal Study of Parents and Children (ALSPAC).

PARTICIPANTS

Our sample included 7921 mothers and 7964 offspring.

MEASUREMENTS

Mental health and non-mental health phenotypes were derived from questionnaires and clinical assessments: 79 maternal phenotypes assessed during and outside of pregnancy and 71 offspring phenotypes assessed in childhood (<10 years) and adolescence (11-18 years).

FINDINGS

The maternal smoking and caffeine GRS were associated with maternal smoking and caffeine consumption during pregnancy (2nd trimester: Psmoking  = 3.0 × 10-7 , Pcaffeine  = 3.28 × 10-5 ). Both the maternal and offspring smoking GRS showed evidence of association with reduced childhood anxiety symptoms (βmaternal  = -0.033; βoffspring  = -0.031) and increased conduct disorder symptoms (βmaternal  = 0.024; βoffspring  = 0.030), after correcting for multiple testing. Finally, the maternal and offspring smoking GRS were associated with phenotypes related to sensation seeking behaviours in mothers and adolescence (e.g. increased symptoms of externalising disorders, extraversion and monotony avoidance). The caffeine GRS showed weaker evidence for associations with mental health outcomes.

CONCLUSIONS

We did not find strong evidence that maternal smoking and caffeine genetic risk scores have a causal effect on offspring mental health outcomes. Our results confirm that the smoking genetic risk scores also captures liability for sensation seeking personality traits.

Deprivation and psychopathology in the Fragile Families Study: A 15-year longitudinal investigation

BACKGROUND

Early adversity consistently predicts youth psychopathology. However, the pathways linking unique dimensions of early adversity, such as deprivation, to psychopathology are understudied. Here, we evaluate a theoretical model linking early deprivation exposure with psychopathology prospectively through language ability.

METHODS

Participants included 2,301 youth (47.5% female) enrolled in the Fragile Families and Child Wellbeing Study. We include data from assessment points at ages 1, 3, 5, 9, and 15. Latent factors for deprivation and threat were modeled from multiple indicators at ages 1 and 3. Youth language ability was assessed at Age 5. Indicators of psychopathology were assessed at ages 5, 9, and 15. A structural equation model tested longitudinal paths to internalizing and externalizing psychopathology from experiences of deprivation and threat.

RESULTS

Deprivation from birth to Age 3 was associated with an indirect effect on internalizing and externalizing symptoms in early childhood (Age 5), later childhood (Age 9), and adolescence (Age 15) via language ability in early childhood (Age 5). Early threat exposure was associated with increased internalizing and externalizing psychopathology across all ages. There was no significant indirect effect from threat to psychopathology via language ability.

CONCLUSIONS

The effects of deprivation on psychopathology during early childhood, late childhood, and adolescence are explained, in part, through early childhood language ability. Results provide insight into language ability as a possible opportunity for intervention.

Prenatal alcohol and tobacco use and the risk of depression in offspring at age of 17 years: findings from the Raine Study

BACKGROUND

Prenatal alcohol and tobacco exposures have been associated with adverse mental health consequences in offspring. The objective of this study was to test the associations between maternal prenatal alcohol and tobacco exposures and depressive symptoms in the offspring, adjusting for a wide range of potential confounders.

METHODS

We used data from 1168 mother-offspring pairs from the Raine Study based in Perth, Western Australia. Depressive symptoms at age 17 years were measured using the Beck Depression Inventory for Youth (BDI-Y). Associations between prenatal alcohol and tobacco use and the risk of depressive symptoms in offspring were estimated by risk ratios (RR) derived with multivariable log-binomial regression.

RESULTS

Among offspring who were assessed for depressive symptoms, 5% were born to mothers who consumed six or more standard drinks of alcohol per week during pregnancy and 20% were exposed to prenatal tobacco. After adjustment for confounders, depressive symptoms at the age of 17 years remained associated with maternal alcohol use of six or more standard drinks per week [RR 1.59 (95% CI: 1.11-2.26)] and any tobacco use [RR 1.36 (95% CI: 1.05-1.79)] during the first trimester of pregnancy.

CONCLUSION

Offspring exposed to prenatal alcohol and tobacco use had greater risks of depressive symptoms compared with unexposed offspring, suggesting early screening and prevention of these exposures could possibly reduce depressive symptoms in offspring.

Prenatal tobacco use and the risk of mood disorders in offspring: a systematic review and meta-analysis

PURPOSE

It is plausible that offspring born to mothers using tobacco during pregnancy may have increased risk of mood disorders (depression and bipolar disorders); however, mixed results have been reported. We conducted a systematic review and meta-analysis to investigate the magnitude and consistency of associations reported between prenatal tobacco use and mood disorders in offspring.

METHODS

We systematically searched EMBASE, SCOPUS, PubMed and Psych-INFO for studies on mood disorders and prenatal tobacco use. Methodological quality of studies was assessed with the revised Newcastle-Ottawa Scale. We estimated pooled relative risk (RR) with inverse variance weighted random-effects meta-analysis. We performed leave-one-out analyses, and stratified analyses by a subgroup (depression and bipolar disorder). Potential publication bias was assessed by inspection of the funnel plot and Egger's test for regression asymmetry. This study protocol was prospectively registered in PROSPERO (CRD42017060037).

RESULTS

Eight cohort and two case-control studies were included in the final meta-analysis. We found an increased pooled relative risk of mood disorders in offspring exposed to maternal prenatal tobacco use RRs 1.43 (95% CI 1.27-1.60) compared to no prenatal tobacco use. Similarly, the pooled relative risks of bipolar and depressive disorders in offspring were 1.44, (95% CI 1.15-1.80) and 1.44, (95% CI 1.21-1.71), respectively. Moreover, the pooled estimated risk of mood disorders was not significantly attenuated in the studies that reported sibling comparison results [RR = 1.21 (95% CI 1.04-1.41)].

CONCLUSION

Taken together, there was strong evidence for a small (RR < 2) association between prenatal tobacco use and mood disorders in offspring.

The Effect of Smoking during Pregnancy on Severity and Directionality of Externalizing and Internalizing Symptoms: A Genetically Informed Approach

The objective was to examine the association between maternal smoking during pregnancy (SDP) and (I) severity and (II) directionality of externalizing and internalizing symptoms in a sample of sibling pairs while rigorously controlling for familial confounds. The Missouri Mothers and Their Children Study is a family study (N = 173 families) with sibling pairs (aged 7 to 16 years) who are discordant for exposure to SDP. This sibling comparison study is designed to disentangle the effects of SDP from familial confounds. An SDP severity score was created for each child using a combination of SDP indicators (timing, duration, and amount). Principal component analysis of externalizing and internalizing behavior, assessed with the Child Behavior Checklist and Teacher Report Form, was used to create symptom severity and directionality scores. The variance in severity and directionality scores was primarily a function of differences between siblings (71% and 85%, respectively) rather than differences across families (29% and 15%, respectively). The severity score that combines externalizing and internalizing symptom severity was not associated with SDP. However, a significant within-family effect of SDP on symptom directionality (b = 0.07, p = 0.04) was observed in the sibling comparison model. The positive directionality score indicates that SDP is associated with differentiation of symptoms towards externalizing rather than internalizing symptoms after controlling for familial confounds with a sibling comparison model. This supports a potentially causal relationship between SDP and externalizing behavior.

Prenatal tobacco exposure and psychiatric outcomes in adolescence: is the effect mediated through birth weight?

OBJECTIVE

This study aims to examine the associations between prenatal exposure to maternal smoking, birth weight and persistent offspring psychiatric symptoms. Additionally, we aim to examine whether the relationship between prenatal maternal smoking and persistent offspring psychiatric symptoms is mediated by offspring birth weight.

METHODS

This study used the Growing Up in Ireland (GUI) longitudinal cohort. The GUI is a nationally representative longitudinal study of children which consisted of three data collection waves, at ages 9, 13, and 17 years. Logistic regression analysis was used to examine associations between prenatal tobacco exposure, and offspring psychiatric symptoms. Linear regression was used to examine associations between prenatal tobacco exposure and offspring birth weight. We conducted a mediation analysis examining potential etiological pathways linking maternal smoking during pregnancy, offspring birth weight, and later offspring psychiatric symptoms. All analyses were adjusted for confounders including household income, maternal level of education, and family psychiatric history. Additionally, examination of birth weight and subsequent psychiatric symptoms also was controlled for prematurity.

RESULTS

We found that the association between prenatal tobacco exposure and later psychiatric symptoms is mediated by birth weight.

CONCLUSIONS

This work provides further evidence that maternal smoking during pregnancy is an important modifiable lifestyle factor that has an impact not just on the physical health of offspring but also their mental wellbeing. Supporting women with structured smoking cessation programs at the earliest stages of pregnancy should be a public health priority.

Electronic cigarettes may not be a "safer alternative" of conventional cigarettes during pregnancy: evidence from the nationally representative PRAMS data

Background

Conventional cigarette (CC) smoking is one of the most preventable causes of adverse birth outcomes. Although electronic cigarettes (ECs) are considered to be safer than CCs during pregnancy, the evidence is yet to be presented. This study examines the effects of prenatal EC use on neonatal birth outcomes compared to those of CC smokers and complete tobacco abstainers.

Methods

Data was extracted from 55,251 pregnant women who participated in the Phase 8 survey of the Pregnancy Risk Assessment Monitoring System between 2016 and 2018. Participants were classified into three groups based on their smoking behaviors in the third trimester: complete tobacco abstinence, exclusive CC smoking, or exclusive EC use. Adverse outcomes included infants being small-for-gestational-age (SGA), having low birthweight (LBW), and being born at preterm. EC users were matched to complete abstainers and CC smokers who share the same baseline characteristics in race/ethnicity, age, educational attainment, income, prenatal care adequacy, and first- and second-trimester CC smoking statuses. The association between EC use and adverse birth outcomes were examined by survey-weighted logistic regression analyses in the matched population.

Results

Among participants, 1.0% of women reported having used ECs during the third trimester, 60% of which reported using ECs exclusively. Neonates of EC users were significantly more likely to be SGA (OR 1.76; 95% CI 1.04, 2.96), have LBW (OR 1.53; 95% CI 1.06, 2.22), or be born preterm (OR 1.86; 95% CI 1.11, 3.12) compared to tobacco abstainers. However, odds of EC users’ pregnancies resulting in SGA (OR 0.67; 95% CI 0.30, 1.47), LBW (OR 0.71; 95% CI 0.37, 1.37), or preterm birth (OR 1.06; 95% CI 0.46, 2.48) were not significantly lower than those of CC smokers.

Conclusions

Even after accounting for shared risk factors between prenatal tobacco use and adverse birth outcomes, EC use remains an independent risk factor for neonatal complications and is not a safer alternative to CC smoking during pregnancy. Until further research is completed, all pregnant women are encouraged to abstain from all tobacco products including ECs.

Prenatal risk factors for internalizing and externalizing problems in childhood

BACKGROUND

A growing body of research has documented the effects of prenatal risk factors on a wide spectrum of adverse offspring health outcomes. Childhood behavior problems, such as externalizing and internalizing problems, are no exception. This comprehensive literature review aims to summarize and synthesize current research about commonly experienced prenatal risk factors associated with internalizing and externalizing problems, with a focus on their impact during childhood and adolescence. Potential mechanisms as well as implications are also outlined.

DATA SOURCES

The EBSCO, Web of Science, PubMed, Google Scholar, and Scopus databases were searched for studies examining the association between prenatal risk factors and offspring internalizing/externalizing problems, using keywords "prenatal" or "perinatal" or "birth complications" in combination with "internalizing" or "externalizing". Relevant articles, including experimental research, systematic reviews, meta-analyses, cross-sectional and longitudinal cohort studies, and theoretical literature, were reviewed and synthesized to form the basis of this integrative review.

RESULTS

Prenatal risk factors that have been widely investigated with regards to offspring internalizing and externalizing problems encompass health-related risk factors, including maternal overweight/obesity, substance use/abuse, environmental toxicant exposure, maternal infection/inflammation, as well as psychosocial risk factors, including intimate partner violence, and anxiety/depression. Collectively, both epidemiological and experimental studies support the adverse associations between these prenatal factors and increased risk of emotional/behavioral problem development during childhood and beyond. Potential mechanisms of action underlying these associations include hormonal and immune system alterations. Implications include prenatal education, screening, and intervention strategies.

CONCLUSIONS

Prenatal risk factors are associated with a constellation of offspring internalizing and externalizing problems. Identifying these risk factors and understanding potential mechanisms will help to develop effective, evidence-based prevention, and intervention strategies.

Neuroinflammatory and Behavioral Outcomes Measured in Adult Offspring of Mice Exposed Prenatally to E-Cigarette Aerosols

BACKGROUND

In an effort to decrease the rates of smoking conventional tobacco cigarettes, electronic cigarettes (e-cigarettes) have been proposed as an effective smoking cessation tool. However, little is known about their toxicological impacts. This is concerning given that e-cigarette use is perceived as less harmful than conventional tobacco cigarettes during pregnancy for both the mother and fetus.

OBJECTIVE

The goal of this study was to test the neurodevelopmental consequences of maternal e-cigarette use on adult offspring behavior and neuroimmune outcomes.

METHODS

Pregnant female CD-1 mice were randomly assigned to one of three treatment groups (n=8-10 per group) and exposed daily to either filtered air, propylene glycol and vegetable glycerol (50:50 PG/VG vehicle), or to PG/VG with 16mg/mL nicotine (+Nic). Whole-body exposures were carried out for 3 h/d, 7 d/week, from gestational day (GD)0.5 until GD17.5. Adult male and female offspring (8 weeks old) were assessed across a battery of behavioral assessments followed by region-specific quantification of brain cytokines using multiplex immunoassays.

RESULTS

Adult offspring of both sexes exposed to +Nic exhibited elevated locomotor activity in the elevated plus maze and altered stress-coping strategies in the forced swim task. Moreover, male and female offspring exposed to PG/VG with and without nicotine had a 5.2% lower object discrimination score in the novel object recognition task. In addition to differences in offspring behavior, maternal e-cigarette exposure with nicotine led to a reduction in interleukin (IL)-4 and interferon-gamma (IFNγ) in the diencephalon, as well as lower levels of hippocampal IFNγ (females only). E-cigarette exposure without nicotine resulted in a 2-fold increase of IL-6 in the cerebellum.

DISCUSSION

These findings support previous adverse findings of e-cigarette exposure on neurodevelopment in a mouse model and provide substantial evidence of persistent adverse behavioral and neuroimmunological consequences to adult offspring following maternal e-cigarette exposure during pregnancy. https://doi.org/10.1289/EHP6067.

Antenatal determinants of early childhood talking delay and behavioural difficulties

The determinants of talking delay alone or its comorbidity with behavioural difficulties was examined in 5768 two-year-old members of the Growing Up in New Zealand longitudinal study. Using the MacArthur-Bates Communicative Development inventories and the total difficulties score from the preschool Strengths and Difficulties Questionnaire, a composite measure was created so that children were categorised as showing no language or behavioural concerns (72.5%), behavioural only difficulties (6.1%), language only difficulties (18.1%), and comorbid language and behavioural difficulties (3.3%). Analyses revealed that antenatal factors such as maternal perceived stress, inadequate folate intake, vitamin intake, alcohol consumption during the first trimester and maternal smoking all had a significant effect on child outcomes. In particular, low multivitamin intake and perceived stress during pregnancy were associated with coexisting language and behavioural difficulties. These findings support international research in showing that maternal factors during pregnancy are associated with developmental outcomes in the early childhood period, and demonstrate these associations within a NZ context. Interventions which address maternal stress management and health behaviours during pregnancy could be beneficial to offspring development.

Myo-inositol mediates the effects of traffic-related air pollution on generalized anxiety symptoms at age 12 years

BACKGROUND

Exposure to traffic-related air pollution (TRAP) has been linked to childhood anxiety symptoms. Neuroimaging in patients with anxiety disorders indicate altered neurochemistry.

OBJECTIVES

Evaluate the impact of TRAP on brain metabolism and its relation to childhood anxiety symptoms in the Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS).

METHODS

Adolescents (n = 145) underwent magnetic resonance spectroscopy. Brain metabolites, including myo-inositol, N-acetylaspartate, creatine, choline, glutamate, glutamate plus glutamine, and glutathione were measured in the anterior cingulate cortex. Anxiety symptoms were assessed using the Spence Children's Anxiety Scale. TRAP exposure in early-life, averaged over childhood, and during the 12 months prior to imaging was estimated using a validated land use regression model. Associations between TRAP exposure, brain metabolism, and anxiety symptoms were estimated using linear regression and a bootstrapping approach for testing mediation by brain metabolite levels.

RESULTS

Recent exposure to high levels of TRAP was associated with significant increases in myo-inositol (β = 0.26; 95%CI 0.01, 0.51) compared to low TRAP exposure. Recent elevated TRAP exposure (β = 4.71; 95% CI 0.95, 8.45) and increased myo-inositol levels (β = 2.98; 95% CI 0.43, 5.52) were also significantly associated with increased generalized anxiety symptoms with 12% of the total effect between TRAP and generalized anxiety symptoms being mediated by myo-inositol levels.

CONCLUSIONS

This is the first study of children to utilize neuroimaging to link TRAP exposure, metabolite dysregulation in the brain, and generalized anxiety symptoms among otherwise healthy children. TRAP may elicit atypical excitatory neurotransmission and glial inflammatory responses leading to increased metabolite levels and subsequent anxiety symptoms.

lifetime exposure to traffic-related air pollution and symptoms of depression and anxiety at age 12 years

BACKGROUND

While air pollution has been associated with depression and anxiety in adults, its impact on childhood mental health is understudied.

OBJECTIVE

We examined lifetime exposure to traffic-related air pollution (TRAP) and symptoms of depression and anxiety at age 12 years in the Cincinnati Childhood Allergy and Air Pollution Study cohort.

METHODS

We estimated exposure to elemental carbon attributable to traffic (ECAT), a surrogate of diesel exhaust, at birth, age 12 years, and average exposure throughout childhood, using a validated land use regression model. We assessed depression and anxiety at age 12 years by parent report with the Behavior Assessment System for Children-2, and by child report with the Child Depression Inventory-2 (CDI-2) and the Spence Children's Anxiety Scale (SCAS). Associations between TRAP at birth, age 12 years, and childhood average and mental health outcomes were estimated using linear regression models adjusting for covariates including parent depression, secondhand smoke exposure, race, household income, and others.

RESULTS

Exposure to ECAT was not significantly associated with parent-reported depression or anxiety. However, exposure to ECAT at birth was associated with increased child-reported depression and anxiety. Each 0.25 µg/m3 increase in ECAT was associated with a 3.5 point increase (95% CI 1.6-5.5) in CDI-2 scores and 2.3 point increase (95% CI 0.8-3.9) in SCAS total anxiety scores. We observed similar associations between average childhood ECAT exposures but not for concurrent exposures at age 12.

CONCLUSIONS

TRAP exposure during early life and across childhood was significantly associated with self-reported depression and anxiety symptoms in children. The negative impact of air pollution on mental health previously reported among adults may also be present during childhood.

Prenatal maternal smoking, maternal offending, and offspring behavioural and cognitive outcomes in early childhood

BACKGROUND

Maternal smoking during pregnancy and parental offending are both linked to adverse offspring outcomes. Few studies have examined how these exposures together influence diverse offspring outcomes in early childhood.

AIMS

To examine associations between quantity of prenatal maternal smoking and frequency of maternal offending and offspring behavioural and cognitive outcomes at age 5 years.

METHODS

Over 66,000 Australian children (mean age 5.6 years) were drawn from an intergenerational data linkage study. Unadjusted and adjusted logistic regressions were conducted for the two key exposures (maternal prenatal smoking and mother having at least two criminal convictions) and offspring behavioural and cognitive vulnerabilities. Population attributable fractions (PAFs) were also estimated for each outcome for the two exposures.

RESULTS

Prenatal smoking and maternal offending were, separately and together, associated with most of the developmental vulnerabilities examined, even after adjusting for other familial and prenatal risk factors. PAFs for prenatal smoking ranged from 5.3% to 15.8%, and PAFs for maternal offending ranged from 3.4% to 11.8% across the offspring outcomes.

CONCLUSIONS

Maternal smoking during pregnancy and maternal offending were uniquely associated with a range of offspring vulnerabilities, but mothers who smoked during pregnancy tended to experience multiple problems that should also be considered as indicators of child vulnerabilities. While early behavioural difficulties were evident in these children, it was striking that they were also likely to have cognitive vulnerabilities. Early intervention to support cognitive development in these children may minimise their risk of academic underachievement, long-term disadvantage, and even offending.

Co-use of tobacco and marijuana during pregnancy: Pathways to externalizing behavior problems in early childhood

Use and co-use of tobacco and marijuana during pregnancy are associated with the development of social, cognitive, and behavioral problems for infants and children. However, less is known about the potential developmental impact of the use of tobacco and marijuana in tandem. The present study examined an etiological model for the development of externalizing behavior problems (EBP) in early childhood in a high risk sample (N = 247) of mother-infant dyads with prospective data from pregnancy to 36 months of child age. Co-use during pregnancy and continued maternal tobacco and marijuana use from infancy through early childhood were investigated. Although direct pathways from exposure during pregnancy to EBP were not significant, there was a significant indirect pathway from prenatal tobacco use to EBP via lower breastfeeding duration to lower maternal warmth/sensitivity to EBP, and a pathway from higher maternal affective dysregulation to higher EBP. These results highlight the importance of considering cascading effects of substance use during pregnancy on parental processes within the context of developmental risk and protection.

The impact of pre- and perinatal factors on psychopathology in adulthood

BACKGROUND

There is considerable evidence that pre- and post-natal factors are associated with a wide range of psychopathology in offspring during childhood and adolescence.

OBJECTIVE

The main aims of the present study were to examine the associations between pre- and perinatal factors and psychopathology in offspring during adulthood, and to explore whether family factors (i.e., family cohesion, mother's social support, and father's social support) mediate these relationships.

METHOD

Information on pre- and perinatal events was collected from biological mothers of the participants (N = 315) when they were between 14 and 18 years who were then followed up until they reached age 30.

RESULTS

Maternal obstetric history and illness during first year were significant predictors of offspring anxiety disorder. Maternal emotional health predicted offspring affective disorder. Difficult delivery and breast feeding predicted disruptive disorder. The relationship between maternal obstetric history/emotional health and anxiety/affective disorder was no longer significant after controlling for family cohesion.

LIMITATIONS

The information was based on maternal recall when their offspring were between 14 and 18 years which may be subjected to recall bias.

CONCLUSION

The association between pre- and postnatal factors and psychopathology of offspring during adulthood is mediated by familial factors.

Testing the programming of temperament and psychopathology in two independent samples of children with prenatal substance exposure

Prenatal programming models have rarely been applied to research on children with prenatal substance exposure, despite evidence suggesting that prenatal drug exposure is a form of stress that impacts neurodevelopmental outcomes and risk for psychopathology. Utilizing data from two longitudinal multisite studies comprising children prenatally exposed to substances as well as a nonexposed comparison group (Maternal Lifestyle Study, n = 1,388; Infant Development, Environment, and Lifestyle study, n = 412), we tested whether early phenotypic indicators of hypothesized programming effects, indexed by growth parameters at birth and infant temperament, served as a link between prenatal substance exposure and internalizing and externalizing behavior at age 5. Latent profile analysis indicated that individual differences in reactivity and regulation for infants prenatally exposed to substances was best characterized by four temperament profiles. These profiles were virtually identical across two independent samples, and demonstrated unique associations with adjustment difficulties nearly 5 years later. Results of path analysis using structural equation modeling also showed that increased prenatal substance exposure was linked to poorer growth parameters at birth, profiles of temperamental reactivity in infancy, and internalizing and externalizing behavior at age 5. This pathway was partially replicated across samples. This study was among the first to link known individual-level correlates of prenatal substance exposure into a specific pathway to childhood problem behavior. Implications for the developmental origins of a child's susceptibility to psychopathology as a result of intrauterine substance exposure are discussed.

Prenatal exposures to tobacco and cannabis: Associations with adult electronic cigarette use

INTRODUCTION

Prenatal exposures to tobacco and cannabis are associated with combustible cigarette use. This study evaluated pathways from these prenatal exposures to adult electronic cigarette use. We tested whether there were indirect effects of these prenatal exposures via childhood behavior dysregulation, early tobacco use, and adolescent tobacco dependence.

METHODS

Telephone interviews were conducted with 427 adult offspring (22-33 years old) from 3 prenatal cohorts with trimester-specific data on exposures to tobacco, alcohol, and cannabis. The offspring were 59% Black and 41% White (61% female). Prenatal exposures included quantity/frequency of tobacco, alcohol, and cannabis use by mothers during the first trimester. Using logistic regression and structural equation modeling, we examined the effects of gestational exposures on adult electronic cigarette use via early cigarette use (prior to age 14), controlling for covariates of combustible and electronic cigarette use.

RESULTS

There were no effects of childhood behavioral dysregulation on electronic cigarette use. However, there was a significant indirect effect of prenatal exposures to tobacco and cannabis on electronic cigarette use via early adolescent combustible cigarette use and adolescent risk for tobacco dependence.

CONCLUSIONS

One implication of these findings is that the inter-generational risk for tobacco use conferred via gestational exposures to tobacco and cannabis generalizes to novel products such as electronic cigarettes. These results have implications for public health, as more women use cannabis and co-use cigarettes and cannabis during pregnancy.

Exposure to Environmental Tobacco Smoke in Relation to Behavioral, Emotional, Social and Health Indicators of Slovak School Children

Environmental tobacco smoke (ETS) exposure has been shown in general as a major environmental risk factor and deserves attention in vulnerable population groups. The aim of the project is to analyze the relationships among the ETS and behavior and health in 6−15-year-old children in Slovakia. The status of physical and mental health of children in relation to exposure to tobacco smoke was examined in a representative group of 1478 school children. The methods used, included anonymous questionnaires filled in by parents, Columbia Impairment Scale (CIS), Behavior Problem Index (BPI) and anthropometry. The prevalence of ETS exposure is the highest in the capital (27%) and southern cities. A significant association was found between ETS and age, socio-economic status, incompleteness of the family, level of mother’s education and a higher prevalence of respiratory diseases (26.7%). The relationships of ETS with emotional (CIS scores ≥ 16) and behavioral functions (BPI score ≥ 14) were significant in children exposed to mother’s or father’s smoking at home. In the multivariate analysis these associations were not significant; the factors such as income and completeness of the family were dominant. The results showed mostly the predominant impact of social factors on the physical and mental health status of Slovak school children.

Maternal Smoking in Pregnancy and Offspring Depression: a cross cohort and negative control study

Previous reports suggest that offspring of mothers who smoke during pregnancy have greater risk of developing depression. However, it is unclear whether this is due to intrauterine effects. Using data from the Avon Longitudinal Study of Parents and Children (ALSPAC) from the UK (N = 2,869), the Nord-Trøndelag health study (HUNT) from Norway (N = 15,493), the Pelotas 1982 Birth Cohort Study from Brazil (N = 2,626), and the Swedish Sibling Health Cohort (N = 258 sibling pairs), we compared associations of maternal smoking during pregnancy and mother’s partner’s smoking during pregnancy with offspring depression and performed a discordant sibling analysis. In meta-analysis, maternal smoking during pregnancy was associated with higher odds of offspring depression (OR 1.20, 95% CI:1.08,1.34), but mother’s partner’s smoking during pregnancy was not (OR 1.05, 95% CI:0.94,1.17). However, there was only weak statistical evidence that the odds ratios for maternal and mother’s partner’s smoking differed from each other (p = 0.08). There was no clear evidence for an association between maternal smoking during pregnancy and offspring depression in the sibling analysis. Findings do not provide strong support for a causal role of maternal smoking during pregnancy in offspring depression, rather observed associations may reflect residual confounding relating to characteristics of parents who smoke.

Prenatal tobacco exposure, birthweight, and offspring psychopathology

Although prenatal tobacco exposure (PTE) is associated with several adverse offspring mental health outcomes, mechanisms remain unclear. We test whether associations between PTE and offspring psychopathology are explained by birthweight, one of the earliest-occurring outcomes of PTE. The analysis focuses on 238 offspring from a family study of depression with (1) collected prenatal histories and (2) at least one clinical interview in adulthood to assess psychiatric problems. Exposure was categorized by maternal smoking of ≥10 cigarettes daily/nearly daily; diagnostic outcomes were confirmed by clinicians using the best-estimate procedure, blind to exposure. After adjusting for potential confounders, PTE was associated with 0.7lb(9%) lower birthweight (p=0.0002), increased rates of disruptive behavior disorders [males: OR=2.66(1.15,6.16), and (trend) substance use disorders [females: OR=2.23(0.98,5.09)], and decreased rates of mood disorders (males: OR=0.42(0.17,0.98)]. Birthweight was not independently associated with diagnoses and did not mediate the association between exposure and psychopathology. Maternal smoking has long-term adverse consequences for offspring. Although birthweight cannot be manipulated, smoking is a modifiable risk factor. Thus, cessation efforts focused on pregnant women may not only improve maternal wellbeing, but also mitigate adverse proximal (e.g., birthweight) and long-term (psychopathology) outcomes in offspring.

Familial confounding of the association between maternal smoking during pregnancy and internalizing disorders in offspring

BACKGROUND

Maternal smoking has consistently been associated with multiple adverse childhood outcomes including externalizing disorders. In contrast the association between maternal smoking during pregnancy (MSDP) and internalizing (anxiety and depressive) disorders in offspring has received less investigation.

METHOD

We conducted a nationwide cohort study including 957635 individuals born in Denmark between 1991 and 2007. Data on MSDP and diagnoses of depression or anxiety disorders were derived from national registers and patients were followed up from the age of 5 years to the end of 2012. Hazard rate ratios (HRRs) were estimated using stratified Cox regression models. Sibling data were used to disentangle individual- and familial-level effects of MSDP and to control for unmeasured familial confounding.

RESULTS

At the population level, offspring exposed to MSDP were at increased risk for both severe depression [HRR 1.29, 95% confidence interval (CI) 1.22-1.36] and severe anxiety disorders (HRR 1.26, 95% CI 1.20-1.32) even when controlling for maternal and paternal traits. However, there was no association between MSDP and internalizing disorders when controlling for the mother's propensity for MSDP (depression: HRR 1.11, 95% CI 0.94-1.30; anxiety disorders: HRR 0.94, 95% CI 0.80-1.11) or comparing differentially exposed siblings (depression: HRR 1.18, 95% CI 0.75-1.89; anxiety disorders: HRR 0.87, 95% CI 0.55-1.36).

CONCLUSIONS

The results suggest that familial background factors account for the association between MSDP and severe internalizing disorders not the specific exposure to MSDP.

Developmental toxicity of nicotine: A transdisciplinary synthesis and implications for emerging tobacco products

While the health risks associated with adult cigarette smoking have been well described, effects of nicotine exposure during periods of developmental vulnerability are often overlooked. Using MEDLINE and PubMed literature searches, books, reports and expert opinion, a transdisciplinary group of scientists reviewed human and animal research on the health effects of exposure to nicotine during pregnancy and adolescence. A synthesis of this research supports that nicotine contributes critically to adverse effects of gestational tobacco exposure, including reduced pulmonary function, auditory processing defects, impaired infant cardiorespiratory function, and may contribute to cognitive and behavioral deficits in later life. Nicotine exposure during adolescence is associated with deficits in working memory, attention, and auditory processing, as well as increased impulsivity and anxiety. Finally, recent animal studies suggest that nicotine has a priming effect that increases addiction liability for other drugs. The evidence that nicotine adversely affects fetal and adolescent development is sufficient to warrant public health measures to protect pregnant women, children, and adolescents from nicotine exposure.

Tobacco exposure and maternal psychopathology: Impact on toddler problem behavior

Prenatal exposure to tobacco has consistently predicted later problem behavior for children. However, little is known about developmental mechanisms underlying this association. We examined a conceptual model for the association between prenatal tobacco exposure and child problem behavior in toddlerhood via indirect paths through fetal growth, maternal depression, and maternal aggressive disposition in early infancy and via maternal warmth and sensitivity and infant negative affect in later infancy. The sample consisted of 258 mother-child dyads recruited during pregnancy and assessed periodically at 2, 9, and 16months of child age. Pathways via maternal depression and infant negative affect to toddler problem behavior were significant. Further, combined tobacco and marijuana exposure during pregnancy and reduced fetal growth also demonstrated important associations with infant negative affect and subsequent problem behavior. These results highlight the importance of considering the role of maternal negative affect and poor fetal growth as risk factors in the context of prenatal exposure.

The effects of nicotine on human fetal development

Maternal smoking during pregnancy continues to represent a major public health concern. Nicotine is extremely harmful to the developing fetus through many different mechanisms, and the harms increase with later gestational age at exposure. Pregnancies complicated by maternal nicotine use are more likely to have significant adverse outcomes. Nicotine-exposed children tend to have several health problems throughout their lives, including impaired function of the endocrine, reproductive, respiratory, cardiovascular, and neurologic systems. Poor academic performance and significant behavioral disruptions are also common, including ADHD, aggressive behaviors, and future substance abuse. To diminish the adverse effects from cigarette smoking, some women are turning to electronic cigarettes, a new trend that is increasing in popularity worldwide. They are largely perceived as being safer to use in pregnancy than traditional cigarettes, although there is not adequate evidence to support this claim. At this time, electronic cigarette use during pregnancy cannot be recommended. Birth Defects Research (Part C) 108:181-192, 2016. © 2016 Wiley Periodicals, Inc.

Testing Causal Effects of Maternal Smoking During Pregnancy on Offspring's Externalizing and Internalizing Behavior

Maternal smoking during pregnancy (SDP) is associated with increased risk of externalizing and internalizing behaviors in offspring. Two explanations (not mutually exclusive) for this association are direct causal effects of maternal SDP and the effects of genetic and environmental factors common to parents and offspring which increase smoking as well as problem behaviors. Here, we examined the associations between parental SDP and mother rated offspring externalizing and internalizing behaviors (rated by the Child Behavior Checklist/2-3) at age three in a population-based sample of Dutch twins (N = 15,228 pairs). First, as a greater effect of maternal than of paternal SDP is consistent with a causal effect of maternal SDP, we compared the effects of maternal and paternal SDP. Second, as a beneficial effect of quitting smoking before pregnancy is consistent with the causal effect, we compared the effects of SDP in mothers who quit smoking before pregnancy, and mothers who continued to smoke during pregnancy. All mothers were established smokers before their pregnancy. The results indicated a greater effect of maternal SDP, compared to paternal SDP, for externalizing, aggression, overactive and withdrawn behavior. Quitting smoking was associated with less externalizing, overactive behavior, aggression, and oppositional behavior, but had no effect on internalizing, anxious depression, or withdrawn behavior. We conclude that these results are consistent with a causal, but small, effect of smoking on externalizing problems at age 3. The results do not support a causal effect of maternal SDP on internalizing behaviors.

The association between prenatal environment and children's mental health trajectories from 2 to 14 years

The prenatal period is recognised as a critical period for later behavioural development. This study aimed to elucidate how an adverse prenatal environment, as defined by the presence of a number of known prenatal risk factors, would influence mental health trajectories in children to 14 years of age. The Raine Study provided comprehensive data from 2,900 pregnancies. Offspring were followed up at ages 2, 5, 8, 10, and 14 years using the Child Behaviour Checklist (CBCL). We used linear mixed regression models with random intercept and slope (random effects models) to examine the extent to which the predictor variables considered influenced changes in continuous CBCL total, internalising, and externalising T scores from ages 2 to 14. In the final multivariate models, increased offspring CBCL T scores were significantly predicted by the mother not finishing high school, smoking during pregnancy, having a total family income below the poverty line, being diagnosed with gestational hypertension and experiencing stressful life events during pregnancy. Conversely, as maternal age increased, CBCL T scores were significantly decreased. Child age also significantly interacted with maternal education, total family income, and maternal stressful life events, such that these variables predicted increases in CBCL scores from age 2 to age 10, and from age 2 to age 14 years. In the Raine Study sample, children who experienced adverse prenatal environments experienced increased levels of problem behaviours in childhood, and more problematic mental health trajectories. Maternal health risk behaviours and other psychosocial variables more commonly affected child behaviour than obstetric complications.

Gestational age and adolescent mental health: evidence from Hong Kong's 'Children of 1997' birth cohort

BACKGROUND

Preterm, and more recently early term, birth has been identified as a risk factor for poor health. Whether the sequelae of late preterm or early term birth extends to poor mental health and well-being in adolescence is unclear and has not been systematically assessed.

METHOD

Linear regression was used to assess the adjusted associations of gestational age (very/moderate preterm (<34 weeks, n=85), late preterm (34-36 weeks, n=305), early term (37-38 weeks, n=2228), full term (39-40 weeks, n=4018), late term (41 weeks, n=809), post-term (≥42 weeks, n=213)) with self-reported self-esteem at ∼11 years (n=6935), parent-reported Rutter score assessing the common emotional and behavioural problems at ∼7 years (n=6292) and ∼11 years (n=5596) and self-reported depressive symptoms at ∼13 years (n=5795) in a population-representative Hong Kong Chinese birth cohort 'Children of 1997' where gestational age has little social patterning.

RESULTS

Very/moderate preterm birth was associated with higher Rutter subscore for hyperactivity (ß coefficients 0.5, 95% CI 0.01 to 1.00) at ∼7 years but not at ∼11 years, adjusted for sex, age, socio-economic position, parents' age at birth, birth order and secondhand smoke exposure. Similarly adjusted, late preterm, early term, late term and post-term birth were not associated with self-esteem or depressive symptoms.

CONCLUSIONS

In a population-representative birth cohort from a non-Western-developed setting, gestational age had few associations with mental health and well-being in adolescence, whereas very preterm birth was specifically associated with hyperactivity in childhood. Inconsistencies with studies from Western settings suggest setting specific unmeasured confounding may underlie any observed associations.

Associations between the prenatal environment and cardiovascular risk factors in adolescent girls: Internalizing and externalizing behavior symptoms as mediators

This longitudinal study examines links among adolescent internalizing and externalizing symptoms, the prenatal environment (e.g., nicotine exposure) and pre/perinatal maternal health, and cardiovascular risk factors. Girls (N=262) ages 11-17 reported internalizing and externalizing behaviors and mothers reported about the prenatal environment and maternal health during and 3 months post-pregnancy. Adolescent cardiovascular risk included adiposity, smoking, blood pressure, and salivary C-reactive protein. Internalizing symptoms mediated relations between prenatal exposures/maternal health and adiposity; externalizing symptoms mediated relations between prenatal exposures and adolescent smoking. Healthcare providers who attend to internalizing and externalizing symptoms in girls may ultimately influence cardiovascular health, especially among those with pre/perinatal risk factors.

The School Children Mental Health in Europe (SCMHE) Project: Design and First Results

Background : The School Children Mental Health in Europe (SCMHE) project aims to build up a set of indicators to collect and monitor children's mental health in an efficient and comparable methodology across the EU countries. It concerns primary schools children aged 6 to 11 years a range where few data are available whereas school interventions are promising. Methods : Three informants were used: parents, teachers and children. In selecting instruments language, instruments were selected according to the easiness to translate them: SDQ (Strengths and Difficulties Questionnaire) for parents and teachers and DI (Dominic Interactive). A two-step procedure was used: schools randomization then six children by class in each grade. Results : 9084 children from seven countries (Italy, Netherlands, Germany, Romania, Bulgaria, Lithuania, and Turkey) completed the Dominic Interactive in their own language. 6563 teachers and 6031 parents completed their questionnaire, and a total of 5574 interviews have been completed by the 3 informants. The participation rate of the children with parents in the participating schools was about 66.4%. As expected teachers report more externalised problems and less internalised problems than parents. Children report more internalised problems than parents and teachers. Boys have consistently more externalised problems than girls and this is the reverse for internalised problems. Combining the diverse informants and impairment levels children with problems requiring some sort of mental health care were about 9.9%: 76% did not see any mental health professional: 78.7% In Eastern countries 63.1% in Western Europe.

The impact of maternal smoking during pregnancy on depressive and anxiety behaviors in children: the Norwegian Mother and Child Cohort Study

BACKGROUND

Maternal smoking during pregnancy (MSDP) is associated with multiple adverse childhood outcomes including externalizing behaviors. However, the association between MSDP and internalizing (anxiety and depressive) behaviors in offspring has received less investigation. We aimed to assess the association between MSDP and childhood internalizing (anxiety and depressive) behaviors in a very large, well-characterized cohort study.

METHODS

We assessed the association between MSDP and internalizing behaviors in offspring utilizing information drawn from 90,040 mother-child pairs enrolled in the Norwegian Mother and Child Cohort Study. Mothers reported smoking information, including status and frequency of smoking, twice during pregnancy. Mothers also reported their child's internalizing behaviors at 18 months, 36 months, and 5 years. Associations between MSDP and childhood internalizing behaviors, including dose-response and timing of smoking in pregnancy, were assessed at each time point.

RESULTS

MSDP was associated with increased internalizing behaviors when offspring were aged 18 months (B = 0.11, P <0.001) and 36 months (B = 0.06, P <0.01), adjusting for numerous potential confounders. Higher rates of smoking (e.g., >20 cigarettes per day) were associated with higher levels of internalizing behaviors. Maternal smoking during early pregnancy appeared to be the critical period for exposure.

CONCLUSIONS

We found evidence supporting a potential role for MSDP in increasing internalizing (anxiety and depressive) behaviors in offspring. We also found evidence supportive of a possible causal relationship, including dose-dependency and support for a predominant role of early pregnancy exposure. Further investigation utilizing genetically informed designs are warranted to assess this association.

Does adolescent's exposure to parental intimate partner conflict and violence predict psychological distress and substance use in young adulthood? A longitudinal study

Little is known about the extent to which parental conflict and violence differentially impact on offspring mental health and substance use. Using data from a longitudinal birth cohort study this paper examines: whether offspring exposure to parental intimate partner violence (involving physical violence which may include conflicts and/or disagreements) or parental intimate partner conflict (conflicting interactions and disagreements only) are associated with offspring depression, anxiety and substance use in early adulthood (at age 21); and whether these associations are independent of maternal background, depression and anxiety and substance use. Data (n=2,126 women and children) were taken from a large-scale Australian birth-cohort study, the Mater University of Queensland Study of Pregnancy (MUSP). IPC and IPV were measured at the 14-year follow-up. Offspring mental health outcomes--depression, anxiety and substance use--were assessed at the 21-year follow-up using the Composite International Diagnostic Interview (CIDI). Offspring of women experiencing IPV at the 14-year follow-up were more likely to manifest anxiety, nicotine, alcohol and cannabis disorders by the 21-year follow-up. These associations remained after adjustment for maternal anxiety, depression, and other potential confounders. Unlike males who experience anxiety disorders after exposure to IPV, females experience depressive and alcohol use disorders. IPV predicts offspring increased levels of substance abuse and dependence in young adulthood. Gender differences suggest differential impact.

Prenatal cocaine exposure: the role of cumulative environmental risk and maternal harshness in the development of child internalizing behavior problems in kindergarten

This study examined the associations between prenatal exposure to cocaine and other substances and child internalizing behavior problems at kindergarten. We investigated whether maternal harshness or cumulative environmental risk mediated or moderated this association. Participants consisted of 216 (116 cocaine exposed, 100 non-cocaine exposed) mother-infant dyads participating in an ongoing longitudinal study of prenatal cocaine exposure. Results indicated that, as hypothesized, maternal harshness moderated the association between prenatal cocaine exposure to child internalizing in kindergarten such that prenatal cocaine exposure increased risk for internalizing problems at high levels of maternal harshness from 7 to 36months and decreased risk at low levels of harshness. Contrary to hypothesis, the association between prenatal cocaine exposure and child internalizing in kindergarten was not mediated by maternal harshness or cumulative environmental risk. However, cumulative environmental risk (from 1month of child age to kindergarten) was predictive of child internalizing behavior problems at kindergarten. Results have implications for parenting interventions that may be targeted toward reducing maternal harshness in high risk samples characterized by maternal substance use in pregnancy.

Prenatal nicotine exposure and child behavioural problems

In utero exposure to tobacco smoke has been related to numerous adverse health effects in new-borns, infants, children, adolescents and adults. The aim of this review was to summarise findings on prenatal nicotine exposure and its relationship with behavioural problems in the offspring. The majority of studies, and especially several recent epidemiological studies, observed a higher likelihood for attention-deficit/hyperactivity disorder (ADHD) or ADHD symptoms in exposed subjects. However, both human and animal studies have failed to provide clear evidence on causality. Existing literature on studies investigating the association between prenatal nicotine exposure and conduct or externalising problems in the offspring suggests a causal effect. The establishment of a final conclusion concerning the relationship between prenatal nicotine exposure and internalising problems in the offspring is complicated by insufficient data and mixed results in epidemiological studies. Prenatal nicotine exposure has been associated with altered brain structure and function in human offspring, and a proposed biological mechanism is related to nicotine's adverse influence on neurotransmitter systems during brain development. In conclusion, establishing a statement on the causality of the relationship between prenatal nicotine exposure and behavioural problems in children remains a challenging task. Nevertheless, considering the results of an increasing number of studies which link prenatal exposure to nicotine to externalising problems applying different methodologies to account for confounding and in view of other adverse health effects known to be caused by this exposure, parents should consider smoking cessation.

Prevention of common mental disorders: what can we learn from those who have gone before and where do we go next?

OBJECTIVE

Prevention strategies have made a major contribution to the considerable successes in reductions in cardiovascular disease and cancer mortality seen in recent decades. However, in the field of psychiatry, similar population-level initiatives in the prevention of common mental disorders, depression and anxiety, are noticeably lacking. This paper aims to provide a brief overview of the existing literature on the topic of the prevention of common mental disorders and a commentary regarding the way forward for prevention research and implementation.

METHODS

This commentary considers what we currently know, what we might learn from the successes and failures of those working in prevention of other high prevalence health conditions, and where we might go from here. Taking cognisance of previous preventive models, this commentary additionally explores new opportunities for preventive approaches to the common mental disorders.

RESULTS

The consensus from a large body of evidence supports the contention that interventions to prevent mental disorders across the lifespan can be both effective and cost-effective. However, funding for research in the area of prevention of common mental disorders is considerably lower than that for research in the areas of treatment, epidemiology and neurobiology. Thus, there is a clear imperative to direct funding towards prevention research to redress this imbalance. Future prevention interventions need to be methodologically rigorous, scalable to the population level and include economic evaluation. Evidence-based knowledge translation strategies should be developed to ensure that all stakeholders recognise preventing mental disorders as an imperative, with appropriate resources directed to this objective.

CONCLUSION

There has been a recent expansion of research into potentially modifiable risk factors for depression, and it is now timely to make a concerted effort to advance the field of prevention of common mental disorders.

Mediating role of stress reactivity in the effects of prenatal tobacco exposure on childhood mental health outcomes

INTRODUCTION

Prenatal tobacco exposure, through maternal smoking during pregnancy, has been associated with adverse mental health outcomes in childhood. However, the mechanisms by which prenatal tobacco exposure compromises mental health later in life are unclear. We hypothesized that sensitized reactivity to stressful life events in early childhood mediates the effect of prenatal tobacco exposure on mental health outcomes in middle childhood, after accounting for earlier mental health outcomes.

METHODS

Data were from 12,308 mothers and their children drawn from the Avon Longitudinal Study of Parents and Children, a large prospective population-based study. Mothers' self-reports of smoking during pregnancy, mothers' ratings of their child's reactivity to stressful life events, and teachers' and mothers' ratings of the Strengths and Difficulties Questionnaire assessing 5 domains of mental health outcomes were measured.

RESULTS

A positive association was found between prenatal tobacco exposure and stress reactivity between the ages of 2 and 6. In turn, stress reactivity was positively associated with peer (isolation), hyperactivity, conduct, and emotional problems (but not prosocial behaviors) between the ages of 7 and 11, after accounting for the mental health outcome at age 4 and other confounders.

CONCLUSIONS

Heightened stress reactivity in preschool ages mediated the effect of prenatal tobacco exposure on adverse mental health outcomes between the ages of 7 and 11. Interventions to assist children exposed to tobacco smoke during gestation in coping with stressful life events may help mitigate psychiatric symptoms in this population.

Training on motor and visual spatial learning tasks in early adulthood produces large changes in dendritic organization of prefrontal cortex and nucleus accumbens in rats given nicotine prenatally

Experience-dependent plasticity is an ongoing process that can be observed and measured at multiple levels. The first goal of this study was to examine the effects of prenatal nicotine on the performance of rats in three behavioral tasks (elevated plus maze (EPM), Morris water task (MWT), and Whishaw tray reaching). The second goal of this experiment sought to examine changes in dendritic organization following exposure to the behavioral training paradigm and/or low doses of prenatal nicotine. Female Long-Evans rats were administered daily injections of nicotine for the duration of pregnancy and their pups underwent a regimen of behavioral training in early adulthood (EPM, MWT, and Whishaw tray reaching). All offspring exposed to nicotine prenatally exhibited substantial increases in anxiety. Male offspring also showed increased efficiency in the Whishaw tray-reaching task and performed differently than the other groups in the probe trial of the MWT. Using Golgi-Cox staining we examined the dendritic organization of the medial and orbital prefrontal cortex as well as the nucleus accumbens. Participation in the behavioral training paradigm was associated with dramatic reorganization of dendritic morphology and spine density in all brain regions examined. Although both treatments (behavior training and prenatal nicotine exposure) markedly altered dendritic organization, the effects of the behavioral experience were much larger than those of the prenatal drug exposure, and in some cases interacted with the drug effects.