Environmental risk factors by gender associated with attention-deficit/hyperactivity disorder

Impacts of Maternal Preeclampsia Exposure on Offspring Neuronal Development: Recent Insights and Interventional Approaches

Preeclampsia, a hypertensive disorder during pregnancy, frequently correlates with adverse neurological outcomes in offspring, including cognitive impairments, autism spectrum disorder, depressive disorder, attention deficit hyperactivity disorder, and cerebral palsy. Despite these known consequences, the understanding of neuronal damage in the offspring of preeclamptic mothers remains insufficient. Here, we review the neuronal abnormalities resulting from maternal preeclampsia exposure, which include disrupted neurogenesis, loss of neuronal cell integrity, accumulation of cellular debris, decreased synaptogenesis and myelination, and increased neurite growth stimulated by maternal preeclampsia serum. The underlying mechanisms potentially driving these effects involve microglial activation, inflammatory responses, and reduced angiogenesis. Intervention strategies aimed at improving fetal neuronal outcomes are also discussed, encompassing pharmacological treatments such as pravastatin, tadalafil, and melatonin, as well as non-pharmacological approaches like dietary modifications, maternal exercise, and standard care for children. These interventions hold promise for clinical application, offering avenues to address early neuronal abnormalities and prevent the onset of long-term neurological disorders.

Maternal choline supplementation modulates cognition and induces anti-inflammatory signaling in the prefrontal cortices of adolescent rats exposed to maternal immune activation

Maternal infection has long been described as a risk factor for neurodevelopmental disorders, especially autism spectrum disorders (ASD) and schizophrenia. Although many pathogens do not cross the placenta and infect the developing fetus directly, the maternal immune response to them is sufficient to alter fetal neurodevelopment, a phenomenon termed maternal immune activation (MIA). Low maternal choline is also a risk factor for neurodevelopmental disorders, and most pregnant people do not receive enough of it. In addition to its role in neurodevelopment, choline is capable of inducing anti-inflammatory signaling through a nicotinic pathway. Therefore, it was hypothesized that maternal choline supplementation would blunt the neurodevelopmental impact of MIA in offspring through long-term instigation of cholinergic anti-inflammatory signaling. To model MIA in rats, the viral mimetic polyinosinic:polycytidylic acid (poly(I:C)) was used to elicit a maternal antiviral innate immune response in dams both with and without choline supplementation. Offspring were reared to both early and late adolescent stages (postnatal days 28 and 50, respectively), where anxiety-related behaviors and cognition were examined. After behavioral testing, animals were euthanized, and their prefrontal cortices (PFCs) were collected for analysis. MIA offspring demonstrated sex-specific patterns of altered cognition and repetitive behaviors, which were modulated by maternal choline supplementation. Choline supplementation also bolstered anti-inflammatory signaling in the PFCs of MIA animals at both early and late adolescent stages. These findings suggest that maternal choline supplementation may be sufficient to blunt some of the behavioral and neurobiological impacts of inflammatory exposures in utero, indicating that it may be a cheap, safe, and effective intervention for neurodevelopmental disorders.

Neurodevelopmental outcomes in children prenatally exposed to opioid maintenance treatment: A population-based study

BACKGROUND AND OBJECTIVES

Opioid maintenance treatment (OMT), with methadone or buprenorphine, is a key approach for managing opioid use disorder (OUD) during pregnancy. Despite buprenorphine's superior short-term outcomes, its long-term effects remain understudied. This study aims to evaluate the effects of prenatal OMT exposure on the incidence of childhood neurodevelopmental disorders (NDDs) considering timing effect.

METHODS

A retrospective cohort study using Rhode Island Medicaid data linked to vital statistics from 2008 to 2018 was conducted. The study included pregnancies having live birth from 2008 to 2016 with continuous Medicaid insurance and OUD diagnosis within 3 months preceding conception until delivery. At least one buprenorphine dispensing or a claim of methadone was required for exposure definition. Exposure was evaluated during early (0-90 days) or late (>90 days) gestation, or at any pregnancy phase. NDDs, including autism, attention-deficit/hyperactivity disorder (ADHD), learning disabilities, speech/language disorders, developmental coordination disorder, intellectual disability, and behavioral disorders, were identified using validated algorithms. Applying Cox proportional-hazard models with propensity score overlap weighting, adjusted hazard ratios (aHR) were calculated, mitigating potential confounders. Children were followed up from birth until NDD diagnosis, disenrollment, or study end.

RESULTS

Of 416 mother-child dyads with OUD, 40% used methadone and 20% had buprenorphine exposure during pregnancy. NDDs were observed in 36% of children with early methadone exposure compared to 17% in the early buprenorphine exposed group (aHR: 2.75; 95% confidence interval [CI]: 1.42-5.35). Further comparison to late buprenorphine exposure, late methadone exposure was associated with higher NDD risk (aHR: 2.05; 95% CI: 1.09-3.86). Compared to unexposed group, children exposed to methadone during early and late periods showed higher NDD incidences (aHR: 2.33; 95% CI: 1.51-3.60 and aHR: 2.42; 95% CI: 1.54-3.80, respectively).

DISCUSSION

The study suggests that buprenorphine is a good treatment option for OUD during pregnancy due to minimal long-term neurodevelopmental impacts on children. However, further extensive research is necessary to rule-out potential confounding.

Looking beyond psychosocial adversity and sex: Clinical factors associated with ADHD and other psychiatric disorders in a non-Caucasian sample of high-risk siblings

This study examined the association of clinical factors, independent of sex and high psychosocial adversity (HPAd), with the presence of ADHD or other mental disorders, specifically within a middle-income country with a non-Caucasian population. A multi-centric cross-sectional study was conducted in three sites in Colombia. Our study recruited trios of an ADHD proband, one sibling, and one parent. We used valid instruments for assessing parents and siblings. The sample included 223 siblings, an average age of 12.3 (SD 3.9), and 51.1% Females. The ADHD recurrence risk ratio (λ) was 12. The clinical factors mainly associated with the presence of ADHD, independent of sex and HPAd, were 1) Pregnancy and childbirth complications, 2) Delayed psychomotor development, 3) Temperament, and 4) Sleep disturbances. Our research showed that, independently of HPAd and the male sex, there were other clinical factors associated with ADHD and other psychiatric disorders in this population. These findings need to be replicated in similar populations globally.

Preeclampsia, Fetal Growth Restriction, and 24-Month Neurodevelopment in Very Preterm Infants

Importance

Preeclampsia has direct influences on a developing fetus and may impact postnatal health, and fetal growth restriction (FGR) is often seen co-occurring with preeclampsia. The development of children born very preterm after preeclampsia diagnosis with and without FGR is not well characterized.

Objective

To examine the associations of preeclampsia and FGR with developmental and/or behavioral outcomes in a cohort of very preterm infants.

Design, Setting, and Participants

In this cohort study, infants in the prospective Neonatal Neurobehavior and Outcomes in Very Preterm Infants study were enrolled between April 2014 and June 2016 from 9 US university-affiliated neonatal intensive care units (NICUs). Eligible infants were born before 30 weeks' gestation. Infants were excluded for any major congenital anomalies and for maternal age younger than 18 years or cognitive impairment impacting the ability to provide informed consent. Data analysis was performed from November 2023 to January 2024.

Exposure

Maternal preeclampsia and FGR in very preterm infants.

Main Outcomes and Measures

The Bayley-III cognition, motor, and language scores less than 85 (-1 SD) indicated developmental delay. Child Behavior Checklist/Preschool 1.5-5 T-scores greater than or equal to 64 for internalizing, externalizing, or total problems indicated clinical importance.

Results

Of 704 infants enrolled, 529 (mean [SD] gestational age, 27.0 [1.9] weeks; 287 male [54.3%]) were studied at 24-month follow-up. A total of 94 infants' mothers had preeclampsia (23.2%), and 46 infants (8.7%) had FGR. In adjusted models, preeclampsia was not associated with Bayley-III (cognitive, B = 3.43 [95% CI, -0.19 to 6.66]; language, B = 3.92 [95% CI, 0.44 to 7.39]; motor, B = 1.86 [95% CI, -1.74 to 5.47]) or Child Behavior Checklist/Preschool 1.5-5 (internalizing, B = -0.08 [95% CI, -2.58 to 2.73]; externalizing, B = 0.69 [95% CI, -1.76 to 3.15]; total, B = 0.21 [95% CI, -2.48 to 2.91]) outcomes. FGR was associated with significantly lower Bayley-III scores (cognitive, B = -8.61 [95% CI, -13.33 to -3.89]; language, B = -8.29 [95% CI, -12.95 to -3.63]; motor, B = -7.60 [95% CI, -12.40 to -2.66]), regardless of preeclampsia status.

Conclusions and Relevance

In this cohort study of preterm infants, preeclampsia was not associated with developmental and/or behavioral outcomes, but infants with FGR may be prone to developmental delays. These findings suggest future areas of research for understanding the roles of preeclampsia and FGR separately and together in early child development for preterm infants.

A Systematic Review and Meta-analysis of Prenatal, Birth, and Postnatal Factors Associated with Attention-Deficit/Hyperactivity Disorder in Children

Previous studies have shown mixed results on the relationship between prenatal, birth, and postnatal ("pregnancy-related") risk factors and attention-deficit/hyperactivity disorder (ADHD). We conducted meta-analyses to identify potentially modifiable pregnancy-related factors associated with ADHD. A comprehensive search of PubMed, Web of Science, and EMBASE in 2014, followed by an updated search in January 2021, identified 69 articles published in English on pregnancy-related risk factors and ADHD for inclusion. Risk factors were included in the meta-analysis if at least three effect sizes with clear pregnancy-related risk factor exposure were identified. Pooled effect sizes were calculated for ADHD overall, ADHD diagnosis, inattention, and hyperactivity/impulsivity. Odds ratios (OR) were calculated for dichotomous measures and correlation coefficients (CC) for continuous measures. Prenatal factors (pre-pregnancy weight, preeclampsia, pregnancy complications, elevated testosterone exposure), and postnatal factors (Apgar score, neonatal illness, no breastfeeding) were positively associated with ADHD overall; the findings for ADHD diagnosis were similar with the exception that there were too few effect sizes available to examine pre-pregnancy weight and lack of breastfeeding. Prenatal testosterone was significantly associated with inattention and hyperactivity/impulsivity. Effect sizes were generally small (range 1.1-1.6 ORs, -0.16-0.11 CCs). Risk factors occurring at the time of birth (perinatal asphyxia, labor complications, mode of delivery) were not significantly associated with ADHD. A better understanding of factors that are consistently associated with ADHD may inform future prevention strategies. The findings reported here suggest that prenatal and postnatal factors may serve as potential targets for preventing or mitigating the symptoms of ADHD.

Predicting childhood ADHD-linked symptoms from prenatal and perinatal data in the ABCD cohort

This study investigates the capacity of pre/perinatal factors to predict attention-deficit/hyperactivity disorder (ADHD) symptoms in childhood. It also explores whether predictive accuracy of a pre/perinatal model varies for different groups in the population. We used the ABCD (Adolescent Brain Cognitive Development) cohort from the United States (N = 9975). Pre/perinatal information and the Child Behavior Checklist were reported by the parent when the child was aged 9-10. Forty variables which are generally known by birth were input as potential predictors including maternal substance-use, obstetric complications and child demographics. Elastic net regression with 5-fold validation was performed, and subsequently stratified by sex, race/ethnicity, household income and parental psychopathology. Seventeen pre/perinatal variables were identified as robust predictors of ADHD symptoms in this cohort. The model explained just 8.13% of the variance in ADHD symptoms on average (95% CI = 5.6%-11.5%). Predictive accuracy of the model varied significantly by subgroup, particularly across income groups, and several pre/perinatal factors appeared to be sex-specific. Results suggest we may be able to predict childhood ADHD symptoms with modest accuracy from birth. This study needs to be replicated using prospectively measured pre/perinatal data.

The causal impact of maternal smoking around birth on offspring ADHD: A two-sample Mendelian randomization study

BACKGROUND

The previous literature highlights a relationship between maternal smoking around birth (MSAB) and offspring attention-deficit/hyperactivity disorder (ADHD). These studies have focused on the causal effects of MSAB on offspring ADHD.

METHOD

A Mendelian randomization analysis was conducted using summary statistics. Data on MSAB were obtained from a recent study including 391,992 participants. ADHD data were obtained from six sources for 246,888 participants. The present study used five methods to examine the causal impact from outcomes on exposures. The inverse variance weighted (IVW) was the main method of analysis, while the other four methods were supplementary methods.

RESULT

The IVW revealed that MSAB was a risk factor for offspring ADHD (OR: 2.54; 95 % confidence interval [CI]: 1.61-4.00, p = 6.04 × 10-5). Concerning ADHD in both sexes, MSAB was associated with females (OR = 3.96, 95 % CI: 1.99-7.90, p = 8.98 × 10-5) and males (OR = 3.74, 95 % CI: 1.74-5.72, p = 1.48 × 10-4). In different diagnosis periods for ADHD, MSAB increased the risk of childhood (OR = 3.63, 95 % CI: 2.25-5.87, p = 1.31 × 10-7), late-diagnosed (OR = 2.99, 95 % CI: 1.74-5.14, p = 7.33 × 10-5), and persistent (OR = 4.77, 95 % CI: 1.88-12.14, p = 1.03 × 10-3) ADHD. The final analysis did not reveal heterogeneity.

CONCLUSIONS

A causal impact of MSAB on offspring ADHD was observed. These findings highlight the need for careful consideration of prenatal exposure (MSAB) during the assessment of offspring ADHD. Additionally, it can provide targeted guidance for prenatal interventions. Future studies should analyze the effects of different doses of maternal smoking on ADHD.

Neurodevelopmental Disruptions in Children of Preeclamptic Mothers: Pathophysiological Mechanisms and Consequences

Preeclampsia (PE) is a multisystem disorder characterized by elevated blood pressure in the mother, typically occurring after 20 weeks of gestation and posing risks to both maternal and fetal health. PE causes placental changes that can affect the fetus, particularly neurodevelopment. Its key pathophysiological mechanisms encompass hypoxia, vascular and angiogenic dysregulation, inflammation, neuronal and glial alterations, and disruptions in neuronal signaling. Animal models indicate that PE is correlated with neurodevelopmental alterations and cognitive dysfunctions in offspring and in humans, an association between PE and conditions such as cerebral palsy, autism spectrum disorder, attention deficit hyperactivity disorder, and sexual dimorphism has been observed. Considering the relevance for mothers and children, we conducted a narrative literature review to describe the relationships between the pathophysiological mechanisms behind neurodevelopmental alterations in the offspring of PE mothers, along with their potential consequences. Furthermore, we emphasize aspects pertinent to the prevention/treatment of PE in pregnant mothers and alterations observed in their offspring. The present narrative review offers a current, complete, and exhaustive analysis of (i) the pathophysiological mechanisms that can affect neurodevelopment in the children of PE mothers, (ii) the relationship between PE and neurological alterations in offspring, and (iii) the prevention/treatment of PE.

Association between cumulative maternal exposures related to inflammation and child attention-deficit/hyperactivity disorder: A cohort study

BACKGROUND

Preclinical studies suggest synergistic effects of maternal inflammatory exposures on offspring neurodevelopment, but human studies have been limited.

OBJECTIVES

To examine the cumulative association and potential interactions between seven maternal exposures related to inflammation and child attention-deficit/hyperactivity disorder (ADHD).

METHODS

We conducted a population-based cohort study of children born from July 2001 to December 2011 in New South Wales, Australia, and followed up until December 2014. Seven maternal exposures were identified from birth data and hospital admissions during pregnancy: autoimmune disease, asthma, hospitalization for infection, mood or anxiety disorder, smoking, hypertension, and diabetes. Child ADHD was identified from stimulant prescription records. Multivariable Cox regression assessed the association between individual and cumulative exposures and ADHD and potential interaction between exposures, controlling for potential confounders.

RESULTS

The cohort included 908,770 children, one-third (281,724) with one or more maternal exposures. ADHD was identified in 16,297 children (incidence 3.5 per 1000 person-years) with median age of 7 (interquartile range 2) years at first treatment. Each exposure was independently associated with ADHD, and risk increased with additional exposures: one exposure (hazard ratio (HR) 1.59, 95% confidence interval (CI) 1.54, 1.65), two exposures (HR 2.25, 95% CI 2.13, 2.37), and three or more exposures (HR 3.28, 95% CI 2.95, 3.64). Positive interaction was found between smoking and infection. The largest effect size was found for cumulative exposure of asthma, infection, mood or anxiety disorder, and smoking (HR 6.12, 95% CI 3.47, 10.70).

CONCLUSIONS

This study identifies cumulative effects of multiple maternal exposures related to inflammation on ADHD, most potentially preventable or modifiable. Future studies should incorporate biomarkers of maternal inflammation and consider gene-environment interactions.

Effect of cesarean section on the risk of autism spectrum disorders/attention deficit hyperactivity disorder in offspring: a meta-analysis

PURPOSE

This study was conducted to investigate the relationship between cesarean section (CS) offspring and autism spectrum disorders (ASD)/attention deficit hyperactivity disorder (ADHD).

METHODS

Searching of the databases (PubMed, Web of Science, Embase, and Cochrane Library) for studies on the relationship between mode of delivery and ASD/ADHD until August 2022. The primary outcome was the incidence of ASD/ADHD in the offspring.

RESULTS

This meta-analysis included 35 studies (12 cohort studies and 23 case-control studies). Statistical results showed a higher risk of ASD (odds ratio (OR) = 1.25, P < 0.001) and ADHD (OR = 1.11, P < 0.001) in CS offspring compared to the VD group. Partial subgroup analysis showed no difference in ASD risk between CS and VD offspring in sibling-matched groups (OR = 0.98, P = 0.625). The risk of ASD was higher in females (OR = 1.66, P = 0.003) than in males (OR = 1.17, P = 0.004) in the CS offspring compared with the VD group. There was no difference in the risk of ASD between CS under regional anesthesia group and VD group (OR = 1.07, P = 0.173). However, the risk of ASD was higher in the CS offspring under general anesthesia than in the VD offspring (OR = 1.62, P < 0.001). CS offspring developed autism (OR = 1.38, P = 0.011) and pervasive developmental disorder-not otherwise specified (OR = 1.46, P = 0.004) had a higher risk than VD offspring, but there was no difference in Asperger syndrome (OR = 1.19, P = 0.115). Offspring born via CS had a higher incidence of ADHD in different subgroup analyses (sibling-matched, type of CS, and study design).

CONCLUSIONS

In this meta-analysis, CS was a risk factor for ASD/ADHD in offspring compared with VD.

Attention-deficit/hyperactivity disorder and inflammation: natural product-derived treatments-a review of the last ten years

OBJECTIVE

Attention-deficit hyperactivity disorder (ADHD) is a psychiatric disorder characterized by symptoms of inattention, hyperactivity, and impulsivity. Stimulant medication is the main pharmacological treatment for ADHD. However, the traditional pharmacological treatments may have significant side effects; therefore, non-pharmacological approaches are needed. Thus, there has been growing interest in alternative herbal treatments. The aim of this review was to comprehensively assess the current evidence for plant-based treatment of ADHD in human and animal models, as well as their ability to modulate the inflammatory process.

METHODS

This study was an integrative review of the current evidence for the plant-based treatment of ADHD. The research involved using literature available on PubMed and Scopus databases.

FINDINGS

Spontaneously hypersensitive rats treated with baicalin exhibited significant reductions in locomotion, increased spatial learning skills, and increased levels of dopamine in the striatum. Supplementation with Sansonite improved memory and attention capacity. In human studies, Ginkgo biloba significantly improved the symptoms of inattention and reduced memory impairment. In studies conducted using Korean Red ginseng, Klamath, and Crocus sativus L., the patients showed significant improvements in symptoms of inattention and hyperactivity/impulsivity. Furthermore, we demonstrated that the identified plants modulate the inflammatory process through pro-inflammatory and anti-inflammatory cytokines, nitric oxide, Th cells, Toll-like receptor 4, and mitogen-activated protein kinases.

CONCLUSION

All the studies included in this review focused on plants with demonstrated potential against inflammatory processes, positioning them as promising candidates for ADHD treatment, due to their potential to attenuate or even prevent neuroinflammatory mechanisms.

Association between 5-min Apgar score and attention deficit hyperactivity disorder: a Scotland-wide record linkage study of 758,423 school children

BACKGROUND

Attention-deficit hyperactivity disorder (ADHD) affects around 1 in 20 children and is associated with life-long sequelae. Previous studies of the association between Apgar score and ADHD have reported inconsistent findings.

METHODS

Record linkage of maternity, prescribing and school pupil census databases was used to conduct a population e-cohort study of singleton children born in Scotland and attending school in Scotland at any point between 2009 and 2013. Binary logistic regression analysis was used to investigate the association between 5-min Apgar score and treated ADHD adjusting for sociodemographic and maternity confounders.

RESULTS

Of the 758,423 children, 7,292 (0.96%) received ADHD medication. The results suggested a potential dose-response relationship between Apgar score and treated ADHD independent of confounders. Referent to an Apgar score of 10, risk of treated ADHD was higher for scores of 0-3 (adjusted OR 1.76, 95% CI 1.32-2.34), 4-6 (adjusted OR 1.50, 95% CI 1.21-1.86) and even 7-9 (adjusted OR 1.26, 95% CI 1.18-1.36) which are traditionally considered within the normal range.

CONCLUSIONS

In addition to reinforcing the need to maximise Apgar score through good obstetric practice, the findings suggest that Apgar score may be useful in predicting future risk of ADHD and therefore facilitating early diagnosis and treatment.

Hypertensive disorders of pregnancy and occurrence of ADHD, ASD, and epilepsy in the child: A meta-analysis

AIM

To synthesize epidemiologic literature pertaining to the association between preeclampsia (PE), attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and epilepsy.

METHOD

A systematic search of PubMed and Embase was performed supplemented by hand-searching of reference lists of eligible studies. Two independent reviewers screened abstracts following a prepared protocol. Data extraction and quality appraisal using the Newcastle Ottawa Scale were performed by an independent reviewer. PRISMA guidelines were followed throughout. Random-effects meta-analyses were performed. Adjusted pooled Odds Ratios and their 95% confidence intervals were reported.

RESULTS

Fifteen out of 121 identified studies were eligible for inclusion. Six reported adjusted estimates for ADHD, resulting in a pooled odds ratio of 1.29 (95% CI: 1.20, 1.38). Eight reported adjusted estimates for ASD, resulting in a pooled odds ratio of 1.27 (95% CI:1.22, 1.32). Three reported adjusted estimates for epilepsy, resulting in a pooled odds ratio of 1.35 (95% CI: 1.12, 1.63).

INTERPRETATION

Intrauterine exposure to PE increased the risk of ADHD, ASD, and epilepsy, though it is unclear whether the true association is with pre-term birth. To our knowledge, this is the first meta-analysis to quantify the association between PE and epilepsy. The results of this meta-analysis can inform screening strategies among children born to preeclamptic mothers for early identification and treatment.

A nationwide, prospective, cohort study on exogenous oxytocin and delays in early child development: the Japan environment and children's study

Although it remains debatable, exogenous oxytocin, commonly used for labour induction and augmentation, reportedly increases risks of neurodevelopment delay, attention-deficit/hyperactivity disorder, and autism spectrum disorder among children prenatally exposed to exogenous oxytocin. However, only few studies have objectively examined exogenous oxytocin's impact on early childhood development through scoring evaluations. This study investigated the association between exogenous oxytocin exposure and neurodevelopment in 3-year-old children using the Ages and Stages Questionnaires, Third Edition. In this nationwide prospective cohort study, we extracted data from 104,062 foetal records regarding exogenous oxytocin use during labour from the Japan Environment and Children's Study. Participants completed questionnaires throughout the pregnancy and postpartum periods. Outcomes comprised the developmental status less than each cut-off value for the five domains of the Ages and Stages Questionnaire, Third Edition. We conducted multivariable logistic regression analyses on the data of 55,400 children after controlling for confounders. Among the 55,400 included women, 19.0% (n = 10,506) used exogenous oxytocin during labour and 81.0% (n = 44,894) did not. Children exposed to exogenous oxytocin showed no significantly increased risk of developmental delay in any domain (communication: odds ratio [OR] 1.04, 95% confidence interval [CI] 0.92-1.16; gross motor: OR 0.97, 95% CI 0.87-1.08; fine motor: OR 1.00, 95% CI 0.92-1.09; problem-solving: OR 1.02, 95% CI 0.94-1.11; personal-social: OR 0.91, 95% CI 0.80-1.03).   Conclusion: Exogenous oxytocin for labour induction did not adversely affect early childhood development. Further studies accounting for the degree of exogenous oxytocin exposure are required to confirm these results. What is Known: • In developed countries, labour is induced in 20-25% of all pregnancies, for which oxytocin is commonly used. • Studies have associated risks of neurodevelopment delay, attention-deficit/hyperactivity disorder, and autism spectrum disorder with exposure to exogenous oxytocin. What is New: • Evaluation with the Ages and Stages Questionnaire, Third Edition, revealed that exogenous oxytocin use did not adversely affect early childhood development. • This prospective study reinforced the lack of evidence of an association between exogenous oxytocin use and early childhood development after adjustment for confounding and rigorous bias elimination.

Family and developmental history of female versus male adolescents with ADHD: diagnosis-specific overlap, few gender/sex differences

Background

Gender and sex differences in the development of children and adolescents are commonly found in the psychiatric examination. Family and developmental history is an important part of the clinical diagnostic interview, the basic examination technique. Attention-deficit/hyperactivity disorder (ADHD) is associated with diagnosis-specific markers in family and development history. However, it is unclear to what extent ADHD-specific signs and narratives differ between females and males. The aim of this study was to assess and to compare the family and developmental history profiles of female versus male adolescents with ADHD.

Methods

Data were collected using the clinical diagnostic interview technique from parents of female and male patients diagnosed with ADHD (ICD-10  F90.0, F90.1 and F98.8) between the ages of 12 and 17  years (n = 92). The two groups were matched in pairs for sex, IQ and ICD-10 diagnosis (F90.0, F90.1 and F98.8). Interview data were operationalized in three categories: 0 - physiological marker, 1 - subclinical marker, 2 - clinical marker. The two groups were compared with two-way ANOVA.

Results

Information about female in comparison to male adolescents were reported in the parental interview with few differences.

Conclusion

Our study suggests that family and developmental history of the neurodevelopmental disorder ADHD is only poorly influenced by gender or sex.

Examining the relationship between birth weight and attention-deficit hyperactivity disorder diagnosis

Background

Attention-deficit hyperactivity disorder (ADHD) is a neurodevelopmental condition that is prevalent in children worldwide. We evaluated the potential relationship between birth weight and ADHD using newly released data from the National Survey of Children's Health 2019-2020.

Methods

This population-based survey study used parent recollection data that were collected and submitted by 50 states and the District of Columbia to the National Survey of Children's Health database from the National Survey of Children's Health database. Those aged < 3 years and without birth weight or ADHD records were excluded. Children were stratified according to ADHD diagnosis and birth weight: very low birth weight (VLBW, < 1,500 g), low birth weight (LBW, 1,500-2,500 g), and normal birth weight (NBW, ≥ 2,500 g). Multivariable logistic regression was applied to examine the causal association between birth weight and ADHD while controlling for child and household characteristics.

Results

The final sample consisted of 60,358 children, of whom 6,314 (9.0%) were reported to have an ADHD diagnosis. The prevalence of ADHD was 8.7% in NBW children, 11.5% in LBW, and 14.4% in VLBW. Compared with NBW children, LBW children [adjusted odds ratio (aOR), 1.32 (95% CI, 1.03-1.68)], and VLBW children [aOR, 1.51 (95% CI, 1.06-2.15)] had a significantly higher risk of ADHD after adjusting all variables. These associations persisted in the male subgroups.

Conclusion and relevance

This study found that LBW and VLBW children were at a higher risk of ADHD.

Screen time and childhood attention deficit hyperactivity disorder: a meta-analysis

OBJECTIVES

The association between screen time and attention deficit hyperactivity disorder (ADHD) has been controversial. This study sheds light on the contentious correlation between screen time and ADHD.

CONTENT

Until August 2022, electronic searches of the PubMed, Embase, and Web of Science databases were carried out. The combined effect value odds ratios (OR) and 95 % confidence interval (95 % CI) were calculated for the meta-analysis using Stata 12.0. There were 81,234 children in the nine studies that made up this meta-analysis which included 28,997 children with ADHD and 52,237 healthy controls. When compared with the screen time <2  h/d, the OR (95 % CI) value of screen time and ADHD in the screen time ≥2 h/d group was 1.51 (1.20-1.90).

SUMMARY AND OUTLOOK

Based on the current meta-analysis results, our study found a positive correlation between screen time and the risk of ADHD. Excessive screen exposure may significantly contribute to the development of ADHD in children. Therefore, it is necessary to reduce screen time per day in children to prevent the occurrence of ADHD.

Short- and Long-Term Outcomes of Preeclampsia in Offspring: Review of the Literature

Preeclampsia is a multisystemic clinical syndrome characterized by the appearance of new-onset hypertension and proteinuria or hypertension and end organ dysfunction even without proteinuria after 20 weeks of pregnancy or postpartum. Residing at the severe end of the spectrum of the hypertensive disorders of pregnancy, preeclampsia occurs in 3 to 8% of pregnancies worldwide and is a major cause of maternal and perinatal morbidity and mortality, accounting for 8-10% of all preterm births. The mechanism whereby preeclampsia increases the risk of the neurodevelopmental, cardiovascular, and metabolic morbidity of the mother's offspring is not well known, but it is possible that the preeclamptic environment induces epigenetic changes that adversely affect developmental plasticity. These developmental changes are crucial for optimal fetal growth and survival but may lead to an increased risk of chronic morbidity in childhood and even later in life. The aim of this review is to summarize both the short- and long-term effects of preeclampsia on offspring based on the current literature.

Predictors of Attention Deficit Hyperactivity Disorder in Sri Lankan Children: A School Based Community Study

OBJECTIVE

To evaluate potential risk-factors of ADHD among primary school-children (PSC) in state schools in Colombo district of Sri Lanka.

METHOD

A case-control study was conducted with 73 cases and 264 controls selected randomly among 6 to 10-year-old PSC from Sinhala medium state schools in Colombo district. Primary care givers completed the SNAP-IV P/T-S scale to screen for ADHD and an interviewer-administered questionnaire on risk-factors. Children's diagnostic status was confirmed by a Consultant Child and Adolescent Psychiatrist based on DSM-5 criteria.

RESULTS

A binomial regression model identified male sex (aOR = 3.45; 95% CI [1.65, 7.18]), lower educational level of the mother (aOR = 2.99; 95% CI [1.31, 6.48]), birth weight <2,500 g (aOR = 2.83; 95% CI [1.17, 6.81]),a neonatal complications (aOR = 3.82; 95% CI [191, 7.65]) and child having witnessed verbal/emotional aggression between parents (aOR = 2.08; 95% CI [1.01, 4.27])as significant predictors of ADHD.

CONCLUSION

Primary prevention should focus on strengthening neonatal, maternal and child health services within the country.

Maternal respiratory viral infections during pregnancy and offspring's neurodevelopmental outcomes: a systematic review

Maternal infections during pregnancy, as cytomegalovirus and zika, have been consistently associated with severe newborn neurodevelopmental conditions, mainly related to vertical transmission and congenital infection. However, little is known about the neurodevelopmental consequences of maternal respiratory viral infections, which are the most prevalent infections during pregnancy. The recent COVID-19 pandemic has increased the interest in understanding the consequences of infections in offspring's development. This systematic review explores whether maternal gestational viral respiratory infections are associated with neurodevelopmental deviations in children below 10 years-old. The search was conducted in Pubmed, PsychInfo and Web of Science databases. 12 articles were revised, including information about maternal infection (Influenza, SARS-CoV-2 and unspecified respiratory infections) and offspring's neurodevelopment (global development, specific functions, temperament and behavioral/emotional aspects). Controversial results were reported regarding maternal respiratory infections during pregnancy and infants' neurodevelopment. Maternal infections seem to be associated with subtle alterations in some offspring's developmental subdomains, as early motor development, and attentional, behavioral/emotional minor problems. Further studies are needed to determine the impact of other psychosocial confounding factors.

Explaining the Association Between Fetal Growth and Childhood ADHD Symptoms: Cross-cohort Replication

The association between restricted fetal growth and symptoms of attention deficit/hyperactivity disorder (ADHD) in childhood is well-replicated and robust. However, fetal growth is determined by many prenatal factors and associations with mental health may be confounded by familial and social context. In this study, we sought to quantify the relative contributions of prenatal factors and familial confounds to the association between fetal growth and ADHD symptoms. Two independent cohorts were analyzed, the Adolescent Brain Cognitive Development study (ABCD; United States) and the Growing Up in Ireland (GUI) study. ADHD symptoms were measured by the Child Behavior Checklist (ABCD) and the Strengths & Difficulties questionnaire (GUI) at age 9-10. Using sequential regression models, we assessed the change-in-association between fetal growth and ADHD symptoms after controlling for sex, familial factors (socioeconomic/demographic factors & family psychiatric history) and prenatal factors (pregnancy complications & maternal substance-use during pregnancy). Converging findings from cohorts suggested that over a quarter of the association between fetal growth and ADHD symptoms is attributable to familial confounds. The degree to which the association was explained by prenatal factors differed by cohort-pregnancy complications explained a larger proportion of the effect in ABCD (7.9%) than GUI (2.7%), and maternal substance-use explained a larger proportion of the effect in GUI (22.7%) compared to ABCD (4.8%). Different explanations of the fetal growth-ADHD association across cohorts suggests cohort-specific, and potentially nationally-specific, risk factors for fetal growth and related neurodevelopmental outcomes. The evidence suggests early prevention of ADHD in Ireland should focus on minimizing maternal smoking during pregnancy. In the US, prevention and treatment of pregnancy complications are highlighted as viable targets for intervention.

Endocytosis of AMPA receptors: Role in neurological conditions

AMPA receptors are glutamate-gated ion channels, present in a wide range of neuron types and in glial cells. Their main role is to mediate fast excitatory synaptic transmission, and therefore, they are critical for normal brain function. In neurons, AMPA receptors undergo constitutive and activity-dependent trafficking between the synaptic, extrasynaptic and intracellular pools. The kinetics of AMPA receptor trafficking is crucial for the precise functioning of both individual neurons and neural networks involved in information processing and learning. Many of the neurological diseases evoked by neurodevelopmental and neurodegenerative malfunctions or traumatic injuries are caused by impaired synaptic function in the central nervous system. For example, attention-deficit/hyperactivity disorder (ADHD), Alzheimer's disease (AD), tumors, seizures, ischemic strokes, and traumatic brain injury are all characterized by impaired glutamate homeostasis and associated neuronal death, typically caused by excitotoxicity. Given the important role of AMPA receptors in neuronal function, it is not surprising that perturbations in AMPA receptor trafficking are associated with these neurological disorders. In this book chapter, we will first introduce the structure, physiology and synthesis of AMPA receptors, followed by an in-depth description of the molecular mechanisms that control AMPA receptor endocytosis and surface levels under basal conditions or synaptic plasticity. Finally, we will discuss how impairments in AMPA receptor trafficking, particularly endocytosis, contribute to the pathophysiology of various neurological disorders and what efforts are being made to therapeutically target this process.

SARS-CoV-2 (COVID-19) as a possible risk factor for neurodevelopmental disorders

Pregnant women constitute one of the most vulnerable populations to be affected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the cause of coronavirus disease 2019. SARS-CoV-2 infection during pregnancy could negatively impact fetal brain development via multiple mechanisms. Accumulating evidence indicates that mother to fetus transmission of SARS-CoV-2 does occur, albeit rarely. When it does occur, there is a potential for neuroinvasion via immune cells, retrograde axonal transport, and olfactory bulb and lymphatic pathways. In the absence of maternal to fetal transmission, there is still the potential for negative neurodevelopmental outcomes as a consequence of disrupted placental development and function leading to preeclampsia, preterm birth, and intrauterine growth restriction. In addition, maternal immune activation may lead to hypomyelination, microglial activation, white matter damage, and reduced neurogenesis in the developing fetus. Moreover, maternal immune activation can disrupt the maternal or fetal hypothalamic-pituitary-adrenal (HPA) axis leading to altered neurodevelopment. Finally, pro-inflammatory cytokines can potentially alter epigenetic processes within the developing brain. In this review, we address each of these potential mechanisms. We propose that SARS-CoV-2 could lead to neurodevelopmental disorders in a subset of pregnant women and that long-term studies are warranted.

Cognitive and Mental Health of Young Mothers' Offspring: A Meta-analysis

BACKGROUND AND OBJECTIVES

The nature and magnitude of the cognitive and mental health risks among the offspring of young mothers is not fully understood. Our objective is to examine the risk of mental disorders in these offspring.

METHODS

Five databases (Medline, Embase, Web of Science, PsycINFO, and CINAHL) were searched from their inceptions until February 2022. Studies were eligible if they assessed offspring of young mothers (&lt;21 years), contained a control group, and assessed any cognitive and/or mental health outcomes. Random-effects meta-analysis was used to generate standardized mean differences (SMDs) in infants (0-3 years), children (4-9), adolescents (10-19), and adults (20+). Methodological bias was assessed using the Newcastle-Ottawa Scale.

RESULTS

51 outcomes were meta-analyzed. Levels of cognitive and learning problems were higher among the infants (SMD = 0.30 [95% confidence interval 0.0-0.55]) and adolescents (SMD = 0.43 [0.24 to 0.62]) of young mothers. Adolescents had more symptoms of delinquency (SMD = 0.24 [0.12 to 0.36]). As adults, they are more often convicted of violent crimes (SMD = 0.36 [0.22 to 0.50]). Internalizing symptoms were higher in these offspring in childhood (SMD = 0.29 [0.14 to 0.45]) and adulthood (SMD = 0.35 [0.34 to 0.36]). This review uses unadjusted data and is thus unequipped to infer causality. Studies have high attrition and rely heavily on self-report.

CONCLUSIONS

Young mothers' offspring have more cognitive, externalizing, and internalizing problems across the lifespan than individuals born to mothers ≥21 years of age. They may benefit from early detection and support.

Prenatal smoking, alcohol and caffeine exposure and offspring externalizing disorders: a systematic review and meta-analysis

BACKGROUND AND AIMS

Several studies have indicated an association between maternal prenatal substance use and offspring externalizing disorders; however, it is uncertain whether this relationship is causal. We conducted a systematic review to determine: (1) if the literature supports a causal role of maternal prenatal substance use on offspring externalizing disorders diagnosis and (2) whether these associations differ across externalizing disorders.

METHODS

We searched Web of Science, Embase, PsycINFO and Medline databases. Risk of bias assessment was conducted using the Newcastle-Ottawa Scale (NOS), and where possible meta-analysis was conducted for studies classed as low risk of bias. We included studies of any design that examined prenatal smoking, alcohol or caffeine use. Studies in non-English language, fetal alcohol syndrome and comorbid autism spectrum disorders were excluded. Participants in the included studies were mothers and their offspring. Measurements included prenatal smoking, alcohol or caffeine use as an exposure, and diagnosis of attention-deficit hyperactivity disorder (ADHD), conduct disorder (CD) and oppositional defiant disorder (ODD) in offspring as an outcome.

RESULTS

We included 63 studies, 46 of which investigated smoking and ADHD. All studies were narratively synthesized, and seven studies on smoking and ADHD were meta-analysed. The largest meta-analysis based on genetically sensitive design included 1 011 546 participants and did not find evidence for an association [odds ratio (OR)_{1-9 cigarettes}  = 0.90, 95% confidence interval (CI) = 0.83-1.11; OR _{> 10 cigarettes}  = 1.04, 95% CI = 0.79-1.36). Studies on alcohol exposure in all the outcomes reported inconsistent findings and no strong conclusions on causality can be made. Studies on caffeine exposure were mainly limited to ADHD and these studies do not support a causal effect.

CONCLUSIONS

There appears to be no clear evidence to support a causal relationship between maternal prenatal smoking and offspring attention-deficit hyperactivity disorder. Findings with alcohol and caffeine exposures and conduct disorder and oppositional-defiant disorder need more research, using more genetically sensitive designs.

A review of infant growth and psychomotor developmental outcomes after intrauterine exposure to preeclampsia

Preeclampsia is a hypertensive disorder of pregnancy with serious health implications for mother and their offspring. The uteroplacental vascular insufficiency caused by preeclampsia is associated with epigenetic and pathological changes in the mother and fetus. However, the impact of preeclampsia in infancy (birth to 2 years), a time of rapid development influenced by pre- and postnatal factors that can predict future health outcomes, remains inconclusive. This narrative review of 23 epidemiological and basic science studies assessed the measurement and impact of preeclampsia exposure on infant growth and psychomotor developmental outcomes from birth to 2 years. Studies assessing infant growth report that preeclampsia-exposed infants have lower weight, length and BMI at 2 years than their normotensive controls, or that they instead experience accelerated weight gain to catch up in growth by 2 years, which may have long-term implications for their cardiometabolic health. In contrast, clear discrepancies remain as to whether preeclampsia exposure impairs infant motor and cognitive development, or instead has no impact. It is additionally unknown whether any impacts of preeclampsia are independent of confounders including shared genetic factors that predispose to both preeclampsia and childhood morbidity, perinatal factors including small for gestational age or preterm birth and their sequelae, and postnatal environmental factors such childhood nutrition. Further research is required to account for these variables in larger cohorts born at term, to help elucidate the independent pathophysiological impact of this clinically heterogenous and dangerous disease.

Relevance of ω-6 GLA Added to ω-3 PUFAs Supplements for ADHD: A Narrative Review

The use of polyunsaturated fatty acids in Attention-Deficit/Hyperactivity Disorder (ADHD) and developmental disorders has been gaining interest with preparations containing different dosages and combinations. Gamma-linolenic acid (GLA) is an ω-6 fatty acid of emerging interest with potential roles as an adjuvant anti-inflammatory agent that could be used with ω-3 PUFAs in the treatment of ADHD and associated symptoms. A narrative review was undertaken to examine the potential role(s) of the ω-6 fatty acid GLA. PubMed, Google Scholar, and Scopus were searched to examine the potential role(s) of the ω-6 fatty acid GLA as (1) an antioxidant and anti-inflammatory agent, (2) a synergistic nutrient when combined with ω-3 PUFAs, and (3) a potential etiological factor in ADHD and its treatment. The results show that GLA exerts anti-inflammatory effects by increasing dihomo-gamma-linolenic acid in immune cells. ω-3 PUFAs, such as EPA and DHA, are often co-administered with GLA because these ω-3 PUFAs may prevent the accumulation of serum arachidonic acid in response to GLA administration without limiting the storage of DGLA in immune cells. The administration of ω-3 PUFAs alone might not be sufficient to effectively treat patients with ADHD and developmental disorders. Overall studies point towards a combination of EPA and DHA with GLA in a 9:3:1 ratio appearing to be associated with ADHD symptom improvement. A combination of PUFAs may lead to better outcomes.

Prenatal and Early Childhood Infections and Subsequent Risk of Obsessive-Compulsive Disorder and Tic Disorders: A Nationwide, Sibling-Controlled Study

BACKGROUND

Postinfectious autoimmune processes are hypothesized to be causally related to both obsessive-compulsive disorder (OCD) and tic disorders, but current evidence is conflicting. This study examined whether prenatal maternal (and paternal, as an internal control) infections and early childhood infections in the offspring (i.e., during the first 3 years of life) were associated with a subsequent risk of OCD and Tourette syndrome or chronic tic disorder (TS/CTD).

METHODS

Individuals exposed to any prenatal maternal infection (n = 16,743) and early childhood infection (n = 264,346) were identified from a population-based birth cohort consisting of 2,949,080 singletons born in Sweden between 1973 and 2003 and were followed through 2013. Cox proportional hazard regression models were used to estimate hazard ratios (HRs). Sibling analyses were performed to control for familial confounding.

RESULTS

At the population level, and after adjusting for parental psychiatric history and autoimmune diseases, a significantly increased risk of OCD and TS/CTD was found in individuals exposed to prenatal maternal (but not paternal) infections (OCD: HR, 1.33; 95% CI, 1.12-1.57; TS/CTD: HR, 1.60; 95% CI, 1.23-2.09) and early childhood infections (OCD: HR, 1.19; 95% CI, 1.14-1.25; TS/CTD: HR, 1.34; 95% CI, 1.24-1.44). However, these associations were no longer significant in the sibling analyses.

CONCLUSIONS

The results do not support the hypothesis that prenatal maternal or early-life infections play a direct causal role in the etiology of either OCD or TS/CTD. Instead, familial factors (e.g., genetic pleiotropy) may explain both the propensity to infections and the liability to OCD and TS/CTD.

Risk of attention-deficit hyperactivity disorder in offspring of mothers with infections during pregnancy

Background

Maternal infections during pregnancy are common events that have been suggested to be risk factors for Attention-deficit hyperactivity disorder (ADHD) in offspring. Only a few studies have been conducted to date and results are conflicting. The current study investigates the associations between specific groups of prenatal maternal infections and offspring ADHD, considering timing of exposure and the role of fever.

Methods

We used data from the prospective Norwegian Mother, Father and Child Cohort Study (MoBa), including more than 112,000 pregnancies, linked with data from the Medical Birth Registry of Norway and the Norwegian Patient Registry to estimate odds ratios for the likelihood that children develop ADHD after being exposed to maternal infections during gestation.

Results

Children exposed to any maternal infection during pregnancy showed increased risk of receiving an ADHD diagnosis (OR = 1.15, CI = 1.03-1.27). Specifically, increased ADHD risk was observed after exposure to genitourinary infections in second (OR = 1.42, CI = 1.06-1.90) or third trimester (OR = 2.04, CI = 1.19-3.49), and to respiratory infections in second trimester (OR = 1.31, CI = 1.12-1.54), provided these infections were accompanied by episodes of fever. Increased ADHD risk was also observed after exposure to diarrhea without fever in the third trimester (OR = 1.25, CI = 1.07-1.46).

Conclusions

Overall, our results suggest that prenatal exposure to maternal infections, particularly with co-occurring episodes of fever, are risk factors for ADHD. Fever (or severity of the infection) appears to be more important in mid-pregnancy associations. Our results indicate that type of infection and timing of exposure might influence the associations, but small effect sizes require careful interpretations. The association between infection and ADHD should be estimated using discordant siblings or other negative control designs that give better adjustment for unmeasured familial confounding.

Maternal oxytocin administration modulates gene expression in the brains of perinatal mice

OBJECTIVES

Oxytocin (OXT) is widely used to facilitate labor. However, little is known about the effects of perinatal OXT exposure on the developing brain. We investigated the effects of maternal OXT administration on gene expression in perinatal mouse brains.

METHODS

Pregnant C57BL/6 mice were treated with saline or OXT at term (n=6-7/group). Dams and pups were euthanized on gestational day (GD) 18.5 after delivery by C-section. Another set of dams was treated with saline or OXT (n=6-7/group) and allowed to deliver naturally; pups were euthanized on postnatal day 9 (PND9). Perinatal/neonatal brain gene expression was determined using Illumina BeadChip Arrays and real time quantitative PCR. Differential gene expression analyses were performed. In addition, the effect of OXT on neurite outgrowth was assessed using PC12 cells.

RESULTS

Distinct and sex-specific gene expression patterns were identified in offspring brains following maternal OXT administration at term. The microarray data showed that female GD18.5 brains exhibited more differential changes in gene expression compared to male GD18.5 brains. Specifically, Cnot4 and Frmd4a were significantly reduced by OXT exposure in male and female GD18.5 brains, whereas Mtap1b, Srsf11, and Syn2 were significantly reduced only in female GD18.5 brains. No significant microarray differences were observed in PND9 brains. By quantitative PCR, OXT exposure reduced Oxtr expression in female and male brains on GD18.5 and PND9, respectively. PC12 cell differentiation assays revealed that OXT induced neurite outgrowth.

CONCLUSIONS

Prenatal OXT exposure induces sex-specific differential regulation of several nervous system-related genes and pathways with important neural functions in perinatal brains.

Comorbidities Associated With Attention-Deficit/Hyperactivity Disorder in Children and Adolescents at a Tertiary Care Setting

Studies have revealed high rates of neurodevelopmental and psychiatric comorbid conditions among individuals diagnosed with attention-deficit/hyperactivity disorder (ADHD). However, research on this topic in the Arab world has been limited. This study evaluates the medical, neurodevelopmental, and psychiatric comorbidities in children and adolescents diagnosed with ADHD in Dubai, United Arab Emirates (UAE). A total of 428 pediatric patients diagnosed with ADHD were included. Children and adolescents with ADHD had high rates of comorbid disorders. Twenty comorbid conditions were identified. More than 3 quarters of the study sample had at least 1 comorbid disorder. The most common comorbidity among children was autism spectrum disorder, and among adolescents was anxiety disorders. Comprehensive assessments are highly warranted to identify and manage associated comorbid conditions. Further research is needed in exploring the biopsychosocial factors contributing to the elevated rate of comorbidity in children and adolescents with ADHD.

Maternal Cigarette Smoke Exposure Exaggerates the Behavioral Defects and Neuronal Loss Caused by Hypoxic-Ischemic Brain Injury in Female Offspring

Objective

Hypoxic-ischemic encephalopathy affects ∼6 in 1,000 preterm neonates, leading to significant neurological sequela (e.g., cognitive deficits and cerebral palsy). Maternal smoke exposure (SE) is one of the common causes of neurological disorders; however, female offspring seems to be less affected than males in our previous study. We also showed that maternal SE exaggerated neurological disorders caused by neonatal hypoxic-ischemic brain injury in adolescent male offspring. Here, we aimed to examine whether female littermates of these males are protected from such insult.

Methods

BALB/c dams were exposed to cigarette smoke generated from 2 cigarettes twice daily for 6 weeks before mating, during gestation and lactation. To induce hypoxic-ischemic brain injury, half of the pups from each litter underwent left carotid artery occlusion, followed by exposure to 8% oxygen (92% nitrogen) at postnatal day (P) 10. Behavioral tests were performed at P40–44, and brain tissues were collected at P45.

Results

Maternal SE worsened the defects in short-term memory and motor function in females with hypoxic-ischemic injury; however, reduced anxiety due to injury was observed in the control offspring, but not the SE offspring. Both hypoxic-ischemic injury and maternal SE caused significant loss of neuronal cells and synaptic proteins, along with increased oxidative stress and inflammatory responses.

Conclusion

Oxidative stress and inflammatory response due to maternal SE may be the mechanism of worsened neurological outcomes by hypoxic-ischemic brain injury in females, which was similar to their male littermates shown in our previous study.

Five-Minute Apgar Score and the Risk of Mental Disorders During the First Four Decades of Life: A Nationwide Registry-Based Cohort Study in Denmark

Objectives:

The associations of long-term risks of the full spectrum of mental disorders with clinically reassuring but suboptimal score range 7–9 remain unclear. This study investigated these associations during up to 38 years of follow-up.

Methods:

In a nationwide cohort study of 2,213,822 singletons born in Denmark during 1978–2015, we used cox regression to estimate the hazard ratio (HR) of mental disorders with a 95% CI.

Results:

A total of 3,00,679 (13.6%) individuals were diagnosed with mental disorders. The associations between suboptimal Apgar score 7–9 and mental disorders differed by attained age. In childhood (≤ 18 years), declining Apgar scores were associated with increased risks of overall mental disorders with HRs (95% CI) of 1.13(1.11-1.15), 1.34 (1.27–1.41), and 1.48 (1.31–1.67) for Apgar scores of 7–9, 4–6, and 1–3, respectively, compared with a score of 10. A dose-response association was seen even within the score range from 9 to 7 (HR 1.11 [95% CI: 1.08–1.13], 1.14 [1.10–1.18], and 1.20 [1.14–1.27], respectively). Of note, individuals with scores of 7–9 had increased risks of organic disorders (HR: 1.27, 95% CI: 1.05–1.53), neurotic disorders (HR: 1.07, 95% CI: 1.03–1.11), and a wide range of neurodevelopmental disorders, such as intellectual disability (1.87, 1.76–1.98), childhood autism (1.13, 1.05–1.22) and attention deficit hyperactivity disorder (1.10, 1.06–1.15). In early adulthood (19–39 years), suboptimal Apgar scores 7–9 were not associated with the risks of overall and specific mental disorders.

Conclusion:

Infants born with clinically reassuring but suboptimal 5-min scores 7–9 are at increased risks of a wide spectrum of mental disorders in childhood.

Maternal infection during pregnancy and the risk of attention-deficit/hyperactivity disorder in the offspring: A systematic review and meta-analysis

BACKGROUND

The effects of maternal infection during pregnancy on the risk of attention-deficit/hyperactivity disorder (ADHD) in the offspring are unclear, and no overview is available.

METHODS

We searched the PubMed and EMBASE databases for relevant studies and performed a systematic review and meta-analysis of the literature.

RESULTS

We found that that maternal infection during pregnancy was associated with a small increase in the risk of ADHD (OR 1.25, 95% CI 1.09, 1.44, P < 0.0001; I² = 92.9%, p < 0.0001) in the offspring. In subgroup analyses, the association remained for maternal genitourinary (GU) infection (OR, 1.19, 1.12, 1.27, P < 0.001; I² = 0%; p = 0.517). However, there was no significant association when we pooled data from siblings from other pregnancies (OR = 1.06, 95% CI, 0.99-1.13, P = 0.084; I² = 0%; p = 0.859), implying that the association was due to confounding.

CONCLUSIONS

The statistically significant association between maternal infection during pregnancy and ADHD in the offspring can be partially explained by unmeasured confounding.

Non-mental diseases associated with ADHD across the lifespan: Fidgety Philipp and Pippi Longstocking at risk of multimorbidity?

Several non-mental diseases seem to be associated with an increased risk of ADHD and ADHD seems to be associated with increased risk for non-mental diseases. The underlying trajectories leading to such brain-body co-occurrences are often unclear - are there direct causal relationships from one disorder to the other, or does the sharing of genetic and/or environmental risk factors lead to their occurring together more frequently or both? Our goal with this narrative review was to provide a conceptual synthesis of the associations between ADHD and non-mental disease across the lifespan. We discuss potential shared pathologic mechanisms, genetic background and treatments in co-occurring diseases. For those co-occurrences for which published studies with sufficient sample sizes exist, meta-analyses have been published by others and we discuss those in detail. We conclude that non-mental diseases are common in ADHD and vice versa and add to the disease burden of the patient across the lifespan. Insufficient attention to such co-occurring conditions may result in missed diagnoses and suboptimal treatment in the affected individuals.

Association of Attention Deficit/Hyperactivity Disorder With Events Occurring During Pregnancy and Perinatal Period

Background: The relationship of events occurring during pregnancy and perinatal period with attention deficit/hyperactivity disorder (ADHD) is not clear. Thus, the focus of the current study was to examine the effects of events occurring during pregnancy and perinatal period on ADHD.

Methods: A two-phase cross-sectional study was performed across 13 schools in Changsha and Yiyang cities from March to December, 2014. We preliminarily screened all students using CBCL and established the diagnosis using Mini International Neuropsychiatric Interview for Children and Adolescents (MINI-KID) and the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). A total of 3,418 questionnaires were effectively completed in this study.

Results: History of threatened abortion (TA) [odds ratio (OR): 1.707 (1.201–2.426)] (vs. No-TA) and neonatal asphyxia (NA) [OR: 2.497(1.225–5.09)] (vs. health) showed a positive association with ADHD. On subgroup analysis, TA [OR: 2.216 (1.458–3.369)] (vs. No-TA) was a risk factor for ADHD without comorbidity; instrumental delivery [OR: 2.748 (1.057–7.142)] (vs. natural birth) and NA [OR: 2.789 (1.222–6.361)] (vs. health) were risk factors for ADHD in the subgroup of ADHD with comorbidity; TA (vs. no-TA) and NA (vs. health) were risk factors for ADHD among male students [ORs: 2.232 (1.439–3.462) and 2.808 (1.115–7.068), respectively], while low birth weight (LBW) (vs. normal birth weight) was a risk factor [OR: 2.054 (1.063–3.967)] for ADHD among female students.

Conclusion: TA was a risk factor for ADHD in the absence of comorbid conditions; instrumental delivery and NA were risk factors for ADHD in the subgroup of ADHD with comorbidity; TA and NA were risk factors for ADHD among male students. LBW was a risk factor for ADHD among female students.

Maternal immune activation and neuroinflammation in human neurodevelopmental disorders

Maternal health during pregnancy plays a major role in shaping health and disease risks in the offspring. The maternal immune activation hypothesis proposes that inflammatory perturbations in utero can affect fetal neurodevelopment, and evidence from human epidemiological studies supports an association between maternal inflammation during pregnancy and offspring neurodevelopmental disorders (NDDs). Diverse maternal inflammatory factors, including obesity, asthma, autoimmune disease, infection and psychosocial stress, are associated with an increased risk of NDDs in the offspring. In addition to inflammation, epigenetic factors are increasingly recognized to operate at the gene-environment interface during NDD pathogenesis. For example, integrated brain transcriptome and epigenetic analyses of individuals with NDDs demonstrate convergent dysregulated immune pathways. In this Review, we focus on the emerging human evidence for an association between maternal immune activation and childhood NDDs, including autism spectrum disorder, attention-deficit/hyperactivity disorder and Tourette syndrome. We refer to established pathophysiological concepts in animal models, including immune signalling across the placenta, epigenetic 'priming' of offspring microglia and postnatal immune-brain crosstalk. The increasing incidence of NDDs has created an urgent need to mitigate the risk and severity of these conditions through both preventive strategies in pregnancy and novel postnatal therapies targeting disease mechanisms.

Is there an association between labor induction and attention-deficit/hyperactivity disorder among children?

BACKGROUND

There is evidence of destructive effects of oxytocin use during labor on neurodevelopment.

PURPOSE

This meta-analysis pooled all observational studies to determine the association between labor induction and the risk of attention-deficit/hyperactivity disorder (ADHD) among children.

METHODS

All observational studies (case-control and cohort) were reviewed until September 2020 after searches of the PubMed, Scopus, and Web of Science databases, the gray literature, and conference proceedings. The pooled odds ratios (ORs), relative ratios (RRs), and 95% confidence intervals (CI (swere calculated as random effect estimates of association among studies.

RESULTS

All observational studies were reviewed, including 4 cohort studies including 2,885,743 participants and 3 casecontrol studies including 51,135 participants (10,961 with ADHD and 40,174 in control groups) with a sample size of 2,936,878 participants. The pooled estimates of OR and RR did not indicate a significant association between labor induction and ADHD among children (OR, 1.13; 95% CI, 0.90-1.35) and (RR, 1.10; 95% CI, 0.96-1.24).

CONCLUSIONS

The findings showed that labor induction is not associated with an increased risk of ADHD among children. However, more studies are needed to investigate the relationship between labor induction and ADHD.

Changes in emotional problems, hyperactivity and conduct problems in moderate to late preterm children and adolescents born between 1958 and 2002 in the United Kingdom

Background

Preterm birth is a risk factor for the development of emotional and behavioural problems in childhood and adolescence. Given the substantial improvements in neonatal care across decades, it has been expected that the difference in emotional problems, hyperactivity, and conduct problems between moderate to late preterm (MLPT) and full term (FT) children and adolescents have declined in recent years.

Methods

Data from four UK population-based studies were used: The National Child Development Study (NCDS; 1958), the British Cohort Study (BCS70; 1970), the Avon Longitudinal Study of Parents and Children (ALSPAC, 1991-1992) and the Millennium Cohort Study (MCS; 2000-2002). Emotional problems, hyperactivity and conduct problems were assessed with mother-reports in early childhood (5-7 years), late childhood (10-11 years) and adolescence (14-16 years). Furthermore, emotional problems were self-reported in adolescence in BCS70, ALSPAC and MCS.

Results

In the most recent cohort, the MLPT group had higher mother-reported emotional problems than those born FT in late childhood and adolescence, whereas there were no differences in self-reported emotional problems in adolescence. Regarding mother-reported hyperactivity symptoms, the MLPT group had higher scores than the FT group in the two most recent cohorts in late childhood and in the most recent cohort in adolescence. Regarding mother-reported conduct problems, MLPT children had significantly higher scores than the FT children in the oldest and in the most recent cohort in late childhood. On the other hand, in adolescence, MLPT children had significantly lower scores in conduct problems in comparison to FT children in the cohort born in 1991-1992.

Conclusions

Mother-reported emotional problems and hyperactivity symptoms of those born MLPT have increased from the birth years 1958 to 2000-2002 during late childhood and adolescence, whereas self-reported emotional problems were similar in MLPT and FT groups during adolescence from 1970 to 2000-2002. Findings are less consistent regarding conduct problems. The current findings highlight the importance of raising the awareness of teachers about the association between MLPT birth and behavioural and emotional problems in late childhood and adolescence to prevent the long-term negative outcomes associated with the sequalae of MLPT birth.

Increased Risk of ADHD at Short and Long Interpregnancy Intervals in a National Birth Cohort

BACKGROUND

Short or long interpregnancy interval (IPI) may adversely impact conditions for foetal development. Whether attention deficit hyperactivity disorder (ADHD) is related to IPI has been largely unexplored.

OBJECTIVES

To examine the association between IPI and ADHD in a large, population-based Finnish study.

METHODS

All children born in Finland between 1991 and 2005 and diagnosed with ADHD (ICD-9 314x or ICD-10 F90.x) from 1995 to 2011 were identified using data from linked national registers. Each subject with ADHD was matched to 4 controls based on sex, date of birth, and place of birth. A total of 9564 subjects with ADHD and 34,479 matched controls were included in analyses. IPI was calculated as the time interval between sibling birth dates minus the gestational age of the second sibling. The association between IPI and ADHD was determined using conditional logistic regression and adjusted for potential confounders.

RESULTS

Relative to births with an IPI of 24 to 59 months, those with the shortest IPI (<6 months) had an increased risk of ADHD (odds ratio [OR] 1.30, 95% confidence interval (CI) 1.12, 1.51) and the ORs for the longer IPI births (60-119 months and ≥120 months) were 1.12 (95% CI 1.02, 1.24) and 1.25 (95% CI 1.08, 1.45), respectively. The association of longer IPI with ADHD was attenuated by adjustment for maternal age at the preceding birth, and comorbid autism spectrum disorders did not explain the associations with ADHD.

CONCLUSIONS

The risk of ADHD is higher among children born following short or long IPIs although further studies are needed to explain this association.

Parental Age and the Risk of ADHD in Offspring: A Systematic Review and Meta-Analysis

Evidence has suggested that parental age at birth is a risk factor of offspring attention deficit/hyperactivity disorder (ADHD). We conducted a meta-analysis of observational studies investigating the association between parental age and offspring ADHD. We conducted a systematic search that followed the recommended guidelines for performing meta-analyses on PUBMED, EMBASE, and Web of Science up to 8 April 2021. We calculated pooled risk estimates from individual age with and without adjusting for possible confounding factors. Dose–response analysis for parental age and ADHD risk was performed. Eleven studies were selected in this meta-analysis, which included 111,101 cases and 4,417,148 participants. Compared with the reference points, the lowest parental age category was associated with an increased risk of ADHD in the offspring, with adjusted odds ratios (ORs) of 1.49 (95% confidence intervals (95%CI) 1.19–1.87) and 1.75 (95%CI 1.31–2.36) for the mother and father, respectively. The highest parental age was statistically insignificant, with adjusted ORs of 1.11 (95%CI 0.79–1.55) and 0.93 (95%CI 0.70–1.23) for mother and father separately. Dose–response analysis indicated a non-linear relationship of parental age with offspring ADHD, with the lowest ADHD risk at 31–35 years old. The results of this meta-analysis support an association between young parental age and the risk of ADHD. More high-quality studies are needed to establish whether the association with parental age is causal.

Prematurity and ADHD in Childhood: An Observational Register-Based Study in Catalonia

Objective: To evaluate the association between prematurity (by the gestational week [gw]) and ADHD during childhood. Method: Observational, matched cohort study using data from children born in a tertiary-level hospital (Hospital Universitari Vall d'Hebron, Catalonia, Spain) during 1995-2007 and data from the Information System for the Development of Research in Primary Health Care (SIDIAP database, Catalonia, Spain). Results: Prevalence of ADHD increases as gestational age decreases, 12.7% for those born ≤28 gw, compared to 3.2% for those born after the 37 gw. The risk of developing ADHD in the non-premature children tends to increase as the gw decreases (35-36 gw, hazard ratio [HR] = 1.70, 95% confidence interval [CI] [1.19, 2.44]; 33-34 gw, HR = 3.38, 95% CI [2.08, 5.50]; 29-32 gw, HR = 2.37, 95% CI [1.54, 3.63]; and ≤28 gw, HR = 5.57, 95% CI [2.49, 12.46]) Conclusion: Being born preterm is associated with a risk of developing ADHD, also in late preterm children (35-36 gw). Attention when taking care of these infants regarding their mental health must be made.

Prenatal and perinatal factors associated with ADHD risk in schoolchildren: EPINED epidemiological study

The aim of this study is to assess the relationship between pre- and perinatal factors and ADHD in a sample of scholars exploring differences between ADHD presentations and spectrum of severity. A total of 6720 scholars (aged 3-4 and 10-11) participated in a double-phase epidemiologic cross-sectional study (Epidemiological Study of Neurodevelopmental Disorders, EPINED), and a sample of 646 scholars (ADHD risk, ASD risk and controls without risk) were individually assessed in the second phase of the study. The ADHD diagnosis, based on DSM-5 criteria, was performed with the Kiddie-Schedule for Affective Disorders & Schizophrenia, Present & Lifetime Version. Associations for the different ADHD presentations between prenatal, perinatal and postnatal factors and ADHD (n = 168), subclinical ADHD (n = 88) and non-ADHD (n = 310) were analysed. Logistic regression models showed that gestational diabetes (p = 0.012), instrumental delivery (p = 0.011), family history of psychopathology (p = 0.033) and maternal ADHD phenotype (p = 0.023) were associated with ADHD. These factors were related to the hyperactive-impulsive and combined presentations, but they were not related to the inattentive presentation. Maternal weight gain was associated with subclinical ADHD. In conclusion, metabolic disorder in the pregnancy, difficulties in childbirth and specific family phenotype were related to ADHD, specifically with hyperactive-impulsive presentation, but not in subclinical ADHD.

Preeclampsia and Neurodevelopmental Outcomes: Potential Pathogenic Roles for Inflammation and Oxidative Stress?

Preeclampsia (PE) is a common and serious hypertensive disorder of pregnancy that occurs in approximately 3-5% of first-time pregnancies and is a well-known leading cause of maternal and neonatal mortality and morbidity. In recent years, there has been accumulating evidence that in utero exposure to PE acts as an environmental risk factor for various neurodevelopmental disorders, particularly autism spectrum disorder and ADHD. At present, the mechanism(s) mediating this relationship are uncertain. In this review, we outline the most recent evidence implicating a causal role for PE exposure in the aetiology of various neurodevelopmental disorders and provide a novel interpretation of neuroanatomical alterations in PE-exposed offspring and how these relate to their sub-optimal neurodevelopmental trajectory. We then postulate that inflammation and oxidative stress, two prominent features of the pathophysiology of PE, are likely to play a major role in mediating this association. The increased inflammation in the maternal circulation, placenta and fetal circulation in PE expose the offspring to both prenatal maternal immune activation-a risk factor for neurodevelopmental disorders, which has been well-characterised in animal models-and directly higher concentrations of pro-inflammatory cytokines, which adversely affect neuronal development. Similarly, the exaggerated oxidative stress in the mother, placenta and foetus induces the placenta to secrete factors deleterious to neurons, and exposes the fetal brain to directly elevated oxidative stress and thus adversely affects neurodevelopmental processes. Finally, we describe the interplay between inflammation and oxidative stress in PE, and how both systems interact to potentially alter neurodevelopmental trajectory in exposed offspring.

Maternal acute and chronic inflammation in pregnancy is associated with common neurodevelopmental disorders: a systematic review

Inflammation is increasingly recognized as a cause or consequence of common problems of humanity including obesity, stress, depression, pollution and disease states such as autoimmunity, asthma, and infection. Maternal immune activation (MIA), triggered by both acute and systemic chronic inflammation, is hypothesized to be one of the mechanisms implicated in the pathogenesis of neurodevelopmental disorders (NDD). Although there is substantial preclinical evidence to support the MIA hypothesis, the human evidence is disparate. We performed a systematic review on human studies examining associations between maternal inflammatory states and offspring NDDs (autism spectrum disorder- ASD, attention deficit hyperactivity disorder-ADHD, Tourette syndrome-TS). 32 meta-analyses and 26 additional individual studies were identified. Maternal states associated with ASD include obesity, gestational diabetes mellitus, pre-eclampsia, pollution, stress, depression, autoimmune diseases, and infection. Maternal states associated with ADHD include obesity, pre-eclampsia, smoking, low socioeconomic status (SES), stress, autoimmune disease, and asthma. Maternal states associated with TS include low SES, depression, and autoimmune diseases. Diverse maternal inflammatory states in pregnancy are associated with common offspring NDDs. Given the increased prevalence of NDDs, there is urgent need to explore relative and cumulative maternal risk factors and disease mechanisms. Defining preventable risk factors in high-risk pregnancies could mitigate the expression and severity of NDDs.

Maternal Vitamin D Levels and the Risk of Offspring Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

Recent evidence has highlighted the importance of vitamin D in the development of the central nervous system. Some studies have shown an association between maternal vitamin D deficiency during pregnancy and offspring attention-deficit/hyperactivity disorder (ADHD) symptoms based on parent or teacher ratings. There are no previous studies on early pregnancy 25-hydroxyvitamin D [25(OH)D] levels and the risk of diagnosed offspring ADHD. Our aim was to examine maternal 25(OH)D levels in early pregnancy and offspring ADHD.

METHOD

In this nationwide population-based case-control study, 1,067 ADHD cases (born between 1998 and 1999 and diagnosed according to the International Classification of Diseases) and 1,067 matched controls were identified from Finnish registers. Maternal 25(OH)D levels were measured using quantitative immunoassay from maternal sera, collected during the first trimester and archived in the national biobank. Conditional logistic regression was used to examine the association between maternal 25(OH)D and offspring ADHD.

RESULTS

There was a significant association between decreasing log-transformed maternal 25(OH)D levels and offspring ADHD both in the unadjusted analyses (odds ratio 1.65; 95% CI 1.33-2.05; p < .001) and in the analyses adjusting for maternal socioeconomic status and age (odds ratio 1.45; 95% CI 1.15-1.81; p = .002). Analyses by quintiles of maternal 25(OH)D levels in the lowest versus highest quintile revealed an adjusted odds ratio for offspring ADHD of 1.53 (95% CI 1.11-2.12; p = .010).

CONCLUSION

This study demonstrated an association between low maternal 25(OH)D during pregnancy and an elevated risk for offspring ADHD. If replicated in independent samples, this finding may have significant public health implications.

Prenatal and Postnatal Predictive Factors for Children's Inattentive and Hyperactive Symptoms at 5 Years of Age: The Role of Early Family-related Factors

We examined several parent-reported prenatal and postnatal factors as potential risk factors for attention-deficit and hyperactivity disorder (ADHD) symptomatology in 5-year-old children. Our study is based on the CHILD-SLEEP birth cohort. Several parental questionnaires were collected prenatally (32nd pregnancy week) and postnatally (i.e. child aged 3, 8, and 24 months and at 5 years). At 5 years of age, ADHD symptoms were assessed using questionnaires. Our main results showed that being a boy, parental depressive symptoms, more negative family atmosphere or a child's shorter sleep duration, and maternal authoritarian parenting style predicted inattentive/hyperactive symptoms. Maternal and paternal authoritative parenting style predicted less inattentive/hyperactive symptoms. Children with several risk factors together had the highest risk for inattentive/hyperactive symptoms. Our findings emphasise the need for early screening and treatment of parental mental health, and early evidence-based targeted parental support, to enable early intervention in those children at a risk of developing ADHD.