Parental asthma occurrence, exacerbations and risk of attention-deficit/hyperactivity disorder

Predictors of preschool attention-deficit/hyperactivity disorder diagnosis: a population-based study using national registers

BACKGROUND

The diagnosis of attention-deficit/hyperactivity disorder (ADHD) in preschool years (before age 6 years) is a marker of severity and poor prognosis. This study investigated a broad range of predictors of ADHD diagnosis during preschool age.

METHODS

Population-based cohort study using Swedish registers. The final sample consisted of all children born in Sweden between 2001 and 2007 who could be linked to both of their biological parents, excluding those who died or emigrated (n = 631,695). Follow-up was completed December 31, 2013. Cox proportional-hazards models for survival analysis were used to identify the predictors that increased the risk of receiving a clinical diagnosis of ADHD from 3 to 5 years. Hazard ratios (HR) with 95% confidence intervals (CI) were presented for each of the 41 selected predictors covering early-onset psychiatric comorbidities, nonpsychiatric medical conditions, parental history and perinatal factors.

RESULTS

At the end of follow-up, 1,686 preschoolers (2.7% of the whole sample) had received a diagnosis of ADHD. We found that 39 out of 41 predictors were associated with increased risk of a later diagnosis of preschool ADHD. Novel associations with preschool ADHD diagnosis were found for gastroesophageal reflux disease (HR = 3.48), premature contractions during pregnancy (HR = 2.03), and criminal conviction history from any parent (HR = 2.14).

CONCLUSIONS

A large number of novel and well-established predictors of preschool ADHD diagnosis were identified. This broad set of early predictors may direct future clinical research and assist in early identification of preschool ADHD.

Maternal asthma and asthma exacerbation during pregnancy and attention-deficit/hyperactivity disorder in offspring: a population-based cohort study

The link between inflammatory disorders, such as asthma, and attention deficit hyperactivity disorder (ADHD) is attracting increasing attention but few studies have examined cross-generational associations. We sought to examine associations of maternal asthma and asthma exacerbation during pregnancy, as well as paternal asthma, with the risk of ADHD in children. This population-based cohort study used data from the Taiwan National Health Insurance Research Database from 2004 to 2017. Cox regression models compared the risk of ADHD in children of parents with and without asthma, adjusting for parental sociodemographic, physical, and mental health conditions, as well as the child's birth weight, and number of births. A sibling control approach was employed to compensate for unmeasured confounders of asthma exacerbation during pregnancy. In the fully adjusted models, maternal and paternal asthma were both significantly associated with an increased risk of ADHD in offspring, with hazard ratios (HRs) of 1.36 (1.31-1.40) and 1.10 (1.05-1.14), respectively. Acute asthma exacerbation during pregnancy was not associated with the risk of further offspring ADHD (adjusted HR 1.00, 95% CI: 0.75-1.34). Both maternal and paternal asthma are associated with an increased risk of ADHD in offspring. The risk was higher from maternal asthma. However, no such association was found with maternal asthma exacerbation during pregnancy of sibling comparison.

Early identification of children with Attention-Deficit/Hyperactivity Disorder (ADHD)

Signs and symptoms of Attention-Deficit/Hyperactivity Disorder (ADHD) are present at preschool ages and often not identified for early intervention. We aimed to use machine learning to detect ADHD early among kindergarten-aged children using population-level administrative health data and a childhood developmental vulnerability surveillance tool: Early Development Instrument (EDI). The study cohort consists of 23,494 children born in Alberta, Canada, who attended kindergarten in 2016 without a diagnosis of ADHD. In a four-year follow-up period, 1,680 children were later identified with ADHD using case definition. We trained and tested machine learning models to predict ADHD prospectively. The best-performing model using administrative and EDI data could reliably predict ADHD and achieved an Area Under the Curve (AUC) of 0.811 during cross-validation. Key predictive factors included EDI subdomain scores, sex, and socioeconomic status. Our findings suggest that machine learning algorithms that use population-level surveillance data could be a valuable tool for early identification of ADHD.

A review of common influencing factors and possible mechanisms associated with allergic diseases complicating tic disorders in children

Over the past few decades, the incidence of childhood allergic diseases has increased globally, and their impact on the affected child extends beyond the allergy itself. There is evidence of an association between childhood allergic diseases and the development of neurological disorders. Several studies have shown a correlation between allergic diseases and tic disorders (TD), and allergic diseases may be an important risk factor for TD. Possible factors influencing the development of these disorders include neurotransmitter imbalance, maternal anxiety or depression, gut microbial disorders, sleep disturbances, maternal allergic status, exposure to tobacco, and environmental factors. Moreover, gut microbial disturbances, altered immunological profiles, and DNA methylation in patients with allergic diseases may be potential mechanisms contributing to the development of TD. An in-depth investigation of the relationship between allergic diseases and TD in children will be important for preventing and treating TD.

Omalizumab in combination with subcutaneous immunotherapy for the treatment of multiple allergies associated with attention-deficit/hyperactivity disorder: a case report and a literature review

We describe the case of a 10-year-old boy with asthma (AS), accompanied by allergic rhinitis (AR), food allergy (FA), and combined attention-deficit/hyperactivity disorder (ADHD), who was treated at Shanghai Renji Hospital on 11 July 2020. The efficiency of the previous treatment with salmeterol/ticlosone was poor. Treatment with montelukast sodium resulted in development of neurological symptoms. Treatment with omalizumab in combination with subcutaneous immunotherapy (SCIT) was then initiated in our department based on anti-asthmatic therapy. Symptoms of asthma were completely controlled, and FA and AR symptoms improved. The treatment regimen led to a significant improvement in ADHD symptoms and the overall quality of life of the patient. The literature search was done in the PubMed database using "attention deficit/hyperactivity disorder/ADHD" and "asthma" as keywords, and we identified 47 relevant articles. In conclusion, our results show that treating asthma with omalizumab in combination with salmeterol/ticlosone and SCIT is efficient in controlling symptoms of multiple allergies and may lead to the improvement in ADHD symptoms and the overall quality of life of pediatric patients with ADHD. While current studies suggest that allergic diseases are closely related to ADHD, there is still a lack of studies or case reports of complete treatment protocols to provide clinical clues for management of the disease.

Maternal asthma symptoms during pregnancy on child behaviour and executive function: A Bayesian phenomics approach

OBJECTIVE

Maternal history of inflammatory conditions has been linked to offspring developmental and behavioural outcomes. This phenomenon may be explained by the maternal immune activation (MIA) hypothesis, which posits that dysregulation of the gestational immune environment affects foetal neurodevelopment. The timing of inflammation is critical. We aimed to understand maternal asthma symptoms during pregnancy, in contrast with paternal asthma symptoms during the same period, on child behaviour problems and executive function in a population-based cohort.

METHODS

Data were obtained from 844 families from the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort. Parent asthma symptoms during the prenatal period were reported. Asthma symptoms in children were reported longitudinally from two to five years old, while behavioural problems and executive functioning were obtained at seven years old. Parent and child measures were compared between mothers with and without prenatal asthma symptoms. Generalized linear and Bayesian phenomics models were used to determine the relation between parent or child asthma symptoms and child outcomes.

RESULTS

Children of mothers with prenatal asthma symptoms had greater behavioural and executive problems than controls (Cohen's d: 0.43-0.75; all p < 0.05). This association remained after adjustments for emerging asthma symptoms during the preschool years and fathers' asthma symptoms during the prenatal period. After adjusting for dependence between child outcomes, the Bayesian phenomics model showed that maternal prenatal asthma symptoms were associated with child internalising symptoms and higher-order executive function, while child asthma symptoms were associated with executive function skills. Paternal asthma symptoms during the prenatal period were not associated with child outcomes.

CONCLUSIONS

Associations between child outcomes and maternal but not paternal asthma symptoms during the prenatal period suggests a role for MIA. These findings need to be validated in larger samples, and further research may identify behavioural and cognitive profiles of children with exposure to MIA.

Asthma in pregnancy: a review of recent literature

PURPOSE OF REVIEW

Asthma remains the most common respiratory disease in pregnancy. Identifying risk factors for asthma exacerbations during pregnancy is critical, as uncontrolled asthma can have detrimental effects for both mother and baby. In this review, we discuss recent literature exploring risk factors, fetal and maternal effects, and treatment options for asthma during pregnancy.

RECENT FINDINGS

Recent literature suggests that optimizing asthma during pregnancy improves outcomes for both mother and baby, as well as later in childhood. Current research affirms that the benefit of asthma medication use outweighs any potential risks related to the medications themselves. Limited information is available regarding the use of newer therapies such as biologics during pregnancy.

SUMMARY

Identifying risk factors for asthma exacerbations during pregnancy is critical to prevent adverse outcomes for both mother and baby. Recent evidence continues to affirm the safety of asthma medication use; more studies are needed regarding the use of new therapies during pregnancy.

Clarifying the relationship and analyzing the influential factors of bronchial asthma in children with attention-deficit hyperactivity disorder

BACKGROUND

Bronchial asthma is closely related to the occurrence of attention-deficit hyperactivity disorder (ADHD) in children, which can easily have adverse effects on children's learning and social interactions. Studies have shown that childhood asthma can increase the risk of ADHD and the core symptoms of ADHD. Compared with children with ADHD alone, children with asthma and ADHD are more likely to show high levels of hyperactivity, hyperactive-impulsive and other externalizing behaviors and anxiety in clinical practice and have more symptoms of somatization and emotional internalization.

AIM

To explore the relationship between ADHD in children and bronchial asthma and to analyze its influencing factors.

METHODS

This retrospective cohort study was conducted at Dongying People's Hospital from September 2018 to August 2023. Children diagnosed with ADHD at this hospital were selected as the ADHD group, while healthy children without ADHD who underwent physical examinations during the same period served as the control group. Clinical and parental data were collected for all participating children, and multivariate logistic regression analysis was employed to identify risk factors for comorbid asthma in children with ADHD.

RESULTS

Significant differences were detected between the ADHD group and the control group in terms of family history of asthma and allergic diseases, maternal complications during pregnancy, maternal use of asthma and allergy medications during pregnancy, maternal anxiety and depression during pregnancy, and parental relationship status (P < 0.05). Out of the 183 children in the ADHD group, 25 had comorbid asthma, resulting in a comorbidity rate of 13.66% (25/183), compared to the comorbidity rate of 2.91% (16/549) among the 549 children in the control group. The difference in the asthma comorbidity rate between the two groups was statistically significant (P < 0.05). The results of the multivariate logistic regression analysis indicated that family history of asthma and allergic diseases, maternal complications during pregnancy, maternal use of asthma and allergy medications during pregnancy, maternal anxiety and depression during pregnancy, and parental relationship status are independent risk factors increasing the risk of comorbid asthma in children with ADHD (P < 0.05).

CONCLUSION

Children with ADHD were more likely to have comorbid asthma than healthy control children were. A family history of asthma, adverse maternal factors during pregnancy, and parental relationship status were identified as risk factors influencing the comorbidity of asthma in children with ADHD. Clinically, targeted interventions based on these factors can be implemented to reduce the risk of comorbid asthma. This information is relevant for results sections of abstracts in scientific articles.

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.

Association and Interacting Factors between Bronchial Asthma and Attention-deficit Hyperactivity Disorder in Children: Meta-analysis and Systematic Review

BACKGROUND

This study aims to systematically assess the possible link between bronchial asthma usage and attention-deficit hyperactivity disorder (ADHD) in children.

METHODS

PubMed, Web of Science, ScienceDirect, CNKI, Wanfang, and the China Biological Medicine Database (CBM) were searched for relevant articles published from database inception until September 28, 2023. The statistical analyses were conducted using Stata 15.1 software, followed by a quantitative meta-analysis to synthesize the results of the odds ratios (ORs) and their corresponding 95% confidence intervals (CIs).

RESULTS

A total of 10 articles involving 729,375 participants were included in the meta-analysis. The overall analysis revealed a statistically significant association between ADHD and an increased likelihood of having bronchial asthma, as indicated by a pooled odds ratio (OR) of 1.46 and a 95% confidence interval (CI) ranging from 1.41 to 1.51, p < 0.001, I2 = 58%. Potential associated factors linking bronchial asthma and ADHD in children include demographic characteristics, healthcare access, socioeconomic factors, comorbidities, genetic susceptibility, immune dysregulation, chronic conditions, growth and development factors, and parental/environmental influences.

CONCLUSION

This systematic review and meta-analysis presents convincing evidence for a notable link between bronchial asthma and ADHD in children. The results indicate an increased likelihood of bronchial asthma among children with ADHD compared to those without the condition. Additionally, various potential factors can underlie the association between bronchial asthma and ADHD in children, necessitating further research to fully comprehend their complex relationship. These findings have implications for clinical practice, highlighting the need for an integrated approach in managing asthma and ADHD.

Neurodevelopmental Outcomes Among Offspring Exposed to Corticosteroid and B2-Adrenergic Agonists In Utero

Importance

Corticosteroids and β2-adrenergic agonists are commonly used during pregnancy to treat asthma. However, offspring neurodevelopmental outcomes following in utero exposure to these medications remain unclear.

Objective

To investigate the association between timing of in utero exposure to corticosteroids and β2-adrenergic agonists and offspring neurodevelopmental milestones during the first 3 years of life.

Design, Setting, and Participants

This cohort study obtained data from the Japan Environment and Children's Study, an ongoing birth cohort study conducted in collaboration with 15 Regional Centers across Japan. Participants were mother-offspring pairs who were recruited between January 1, 2011, and March 31, 2014. Data were analyzed between January and February 2023.

Exposure

Corticosteroids and β2-adrenergic agonists were the exposure of interest. Timing of corticosteroid and β2-adrenergic agonist exposure included early pregnancy (weeks 0-12), mid- to late pregnancy (weeks >12), and both stages of pregnancy.

Main Outcomes and Measures

Offspring neurodevelopmental milestones (communication, gross motor, fine motor, problem-solving, and personal-social skills) were assessed using the Japanese version of the Ages and Stages Questionnaires, 3rd edition, at 6, 12, 18, 24, 30, and 36 months.

Results

In total, 91 460 mother-offspring pairs were analyzed. Among mothers, the mean (SD) age at delivery was 31.20 (5.05) years. Among offspring, 46 596 (50.9%) were males and 44 864 (49.1%) were females, of whom 66.4% had a gestational age of 39 to 41 weeks. During early, mid- to late, and both stages of pregnancy, 401 (0.4%), 935 (1.0%), and 568 (0.6%) offspring, respectively, were exposed to corticosteroids, whereas 170 (0.2%), 394 (0.4%), and 184 (0.2%), respectively, were exposed to β2-adrenergic agonists. No association of corticosteroid exposure during early, mid- to late, and both stages of pregnancy with all 5 neurodevelopmental milestones was found. Similarly, no association between β2-adrenergic agonist use during early pregnancy and all 5 neurodevelopmental milestones was observed. An association was found between β2-adrenergic agonist exposure during mid- to late pregnancy and delayed personal-social skills (adjusted odds ratio, 1.48; 95% CI, 1.01-2.32; P = .045).

Conclusions and Relevance

Results of this study found no association between in utero corticosteroid and β2-adrenergic agonist exposure and offspring neurodevelopmental outcomes, regardless of the timing of exposure. Despite the limitations and low power of the study, the findings suggest that corticosteroids and β2-adrenergic agonists are safe for pregnant individuals with asthma and the neurodevelopment of their offspring.

Comorbidity of asthma in patients with attention-deficit/hyperactivity disorder (ADHD) aged 4-12 years in Iran: a cross-sectional study

Attention-deficit/hyperactivity disorder (ADHD) is defined as a stable pattern of attention deficits or impulsive hyperactivity that can interfere with the functioning, growth, and development of individuals. It is believed that both the type of asthma and the medications used to treat it exacerbate the symptoms of ADHD.

Methods and Materials

The present study was a cross-sectional analytical study conducted to investigate the incidence of asthma in ADHD patients aged 4-12 years who were referred to Urmia University of Medical Sciences clinics and hospitals. In this study, ADHD patients were diagnosed through a psychiatric interview and based on a paediatric asthma questionnaire (approved by asthma and allergy organizations and scientific institutions), and individuals with suspected asthma were selected. All 101 ADHD patients referred to these clinics during the specified period were examined. Five patients were excluded from the study because of lack of cooperation or incomplete information. Then, the selected subjects were divided into two age groups of less than 5 years and between 5 and 12 years. The final diagnosis of asthma was made by clinical findings and demographic questionnaire in subjects younger than 5 years, while it was made by spirometry in subjects between 5 and 12 years. Data analysis was conducted using SPSS software.

Results

The mean age of the 96 samples included in the study was 7.67 years with a standard deviation of 7.214. Sixteen of them (16.7%) were under 5 years of age and eighty of them (83.3%) were between 5 and 12 years of age. Asthma was diagnosed in 7 children under 5 years of age (7.3%) and in 14 children (14.6%) between 5 and 12 years of age. A total of 21 (21.9%) were diagnosed as having asthma after screening. On the basis of these results, the frequency of asthma according to classified age was significant (P=0.020). The frequency of asthma based on sex and birth rank was also examined, and none of these factors showed a significant association with asthma. Medications taken by the ADHD patients were also examined in this study. The most commonly used medications in both groups of patients with asthma and no asthmatic patients were a combination of risperidone and atomoxetine or risperidone alone. The prevalence of asthma in the target population was also assessed in terms of parental smoking.

Conclusions

According to the results of this study, the incidence of asthma in ADHD patients aged 4-12 years is high, and this case is more frequent in subjects younger than 5 years than in subjects aged 5-12 years. It should be noted that according to the results of the present study, there was no significant association between birth rank, parental smoking, ADHD medication, and the frequency of asthma.

Intra-amniotic inflammation in the mid-trimester of pregnancy is a risk factor for neuropsychological disorders in childhood

OBJECTIVES

Intra-amniotic inflammation is a subclinical condition frequently caused by either microbial invasion of the amniotic cavity or sterile inflammatory stimuli, e.g., alarmins. An accumulating body of evidence supports a role for maternal immune activation in the genesis of fetal neuroinflammation and the occurrence of neurodevelopmental disorders such as cerebral palsy, schizophrenia, and autism. The objective of this study was to determine whether fetal exposure to mid-trimester intra-amniotic inflammation is associated with neurodevelopmental disorders in children eight to 12 years of age.

METHODS

This is a retrospective case-control study comprising 20 children with evidence of prenatal exposure to intra-amniotic inflammation in the mid-trimester and 20 controls matched for gestational age at amniocentesis and at delivery. Amniotic fluid samples were tested for concentrations of interleukin-6 and C-X-C motif chemokine ligand 10, for bacteria by culture and molecular microbiologic methods as well as by polymerase chain reaction for eight viruses. Neuropsychological testing of children, performed by two experienced psychologists, assessed cognitive and behavioral domains. Neuropsychological dysfunction was defined as the presence of an abnormal score (<2 standard deviations) on at least two cognitive tasks.

RESULTS

Neuropsychological dysfunction was present in 45% (9/20) of children exposed to intra-amniotic inflammation but in only 10% (2/20) of those in the control group (p=0.03). The relative risk (RR) of neuropsychological dysfunction conferred by amniotic fluid inflammation remained significant after adjusting for gestational age at delivery [aRR=4.5 (1.07-16.7)]. Of the 11 children diagnosed with neuropsychological dysfunction, nine were delivered at term and eight of them had mothers with intra-amniotic inflammation. Children exposed to intra-amniotic inflammation were found to have abnormalities in neuropsychological tasks evaluating complex skills, e.g., auditory attention, executive functions, and social skills, whereas the domains of reasoning, language, and memory were not affected in the cases and controls.

CONCLUSIONS

Asymptomatic sterile intra-amniotic inflammation in the mid-trimester of pregnancy, followed by a term birth, can still confer to the offspring a substantial risk for neurodevelopmental disorders in childhood. Early recognition and treatment of maternal immune activation in pregnancy may be a strategy for the prevention of subsequent neurodevelopmental disorders in offspring.

Interplay of ADHD Polygenic Liability With Birth-Related, Somatic, and Psychosocial Factors in ADHD: A Nationwide Study

OBJECTIVE

Attention deficit hyperactivity disorder (ADHD) is a multifactorial neurodevelopmental disorder, yet the interplay between ADHD polygenic risk scores (PRSs) and other risk factors remains relatively unexplored. The authors investigated associations, confounding, and interactions of ADHD PRS with birth-related, somatic, and psychosocial factors previously associated with ADHD.

METHODS

Participants included a random general population sample (N=21,578) and individuals diagnosed with ADHD (N=13,697) from the genotyped Danish iPSYCH2012 case cohort, born between 1981 and 2005. The authors derived ADHD PRSs and identified 24 factors previously associated with ADHD using national registers. Logistic regression was used to estimate associations of ADHD PRS with each risk factor in the general population. Cox models were used to evaluate confounding of risk factor associations with ADHD diagnosis by ADHD PRS and parental psychiatric history, and interactions between ADHD PRS and each risk factor.

RESULTS

ADHD PRS was associated with 12 of 24 risk factors (odds ratio range, 1.03-1.30), namely, small gestational age, infections, traumatic brain injury, and most psychosocial risk factors. Nineteen risk factors were associated with ADHD diagnosis (odds ratio range, 1.20-3.68), and adjusting for ADHD PRS and parental psychiatric history led to only minor attenuations. Only the interaction between ADHD PRS and maternal autoimmune disease survived correction for multiple testing.

CONCLUSIONS

Higher ADHD PRS in the general population is associated with small increases in risk for certain birth-related and somatic ADHD risk factors, and broadly to psychosocial adversity. Evidence of gene-environment interaction was limited, as was confounding by ADHD PRS and family psychiatric history on ADHD risk factor associations. This suggests that the majority of the investigated ADHD risk factors act largely independently of current ADHD PRS to increase risk of ADHD.

Association of elevated plasma CCL5 levels with high risk for tic disorders in children

Abnormal levels of some peripheral cytokines have been reported in children patients with tic disorders (TDs), but none of these cytokines can be a biomarker for this disease. Our aim was to systemically profile differentially expressed cytokines (DECs) in the blood of TD patients, examine their associations with TD development, and identify from them potential biomarkers for the prediction and management of the risk for TDs. In this study, a cytokine array capable of measuring 105 cytokines was used to screen for DECs in the plasma from 53 comorbidity-free and drug-naïve TD patients and 37 age-matched healthy controls. DECs were verified by ELISA and their associations with TD development were evaluated by binary logistic regression analysis. Elevation of a set of cytokines was observed in TD patients compared with controls, including previously uncharacterized cytokines in tic disorders, CCL5, Serpin E1, Thrombospondin-1, MIF, PDGF-AA, and PDGF-AB/BB. Further analysis of DECs revealed a significant association of elevated CCL5 with TD development (p = 0.005) and a significant ROC curve for CCL5 as a risk factor [AUC, 0.801 (95% CI: 0.707-0.895), p < 0.0001].

Conclusion

This study identifies associations of a set of circulating cytokines, particularly CCL5 with TD development, and provides evidence that high blood CCL5 has potential to be a risk factor for TD development.

Clinical Trial Registration

identifier ChiCTR-2000029616.

Psychopathology of attention deficit/hyperactivity disorder: from an inflammatory perspective

Background

Attention deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inattentiveness, hyperactivity and impulsivity, which may affect one’s cognitive and psychosocial functioning. This review gives an overview of ADHD, particularly from an aetiological and clinical perspective. It also critically examines current evidence on the role of inflammation in ADHD and consolidates key findings in this area of research.

Results

The exact cause of ADHD remains unknown, and the aetiology of the disorder is believed to be multifactorial. Numerous genetic and environmental factors have been linked to the development of ADHD. Like many psychiatric disorders, ADHD has been associated with inflammation that occurs locally and peripherally. A growing body of evidence shows that maternal inflammatory status during pregnancy is associated with diagnosis of ADHD in the offspring, whereas oxidative stress, inflammatory biochemical markers and immune-mediated diseases have been observed in individuals with ADHD.

Conclusions

The underlying inflammatory processes and mechanisms in ADHD are not clearly understood. Therefore, further exploration is warranted in future research. This has clinical implications as inflammation may be a potential target in the treatment of ADHD.

Maternal Allergic Asthma Induces Prenatal Neuroinflammation

Autism spectrum disorder (ASD) is a class of neurodevelopmental disorders characterized by impaired social interactions and communication skills and repetitive or stereotyped behaviors. Rates of ASD diagnosis continue to rise, with current estimates at 1 in 44 children in the US (Maenner 2021). Epidemiological studies have suggested a link between maternal allergic asthma and an increased likelihood of having a child diagnosed with ASD. However, a lack of robust laboratory models prevents mechanistic research from being carried out. We developed a novel mouse model of maternal asthma-allergy (MAA) and previously reported that offspring from these mothers exhibit behavioral deficits compared to controls. In addition, it was shown that epigenetic regulation of gene expression in microglia was altered in these offspring, including several autism candidate genes. To further elucidate if there is neuroinflammation in the fetus following MAA, we investigated how allergic asthma impacts the maternal environment and inflammatory markers in the placenta and fetal brain during gestation. Female C57Bl/6 mice were primed with ovalbumin (OVA) prior to allergic asthma induction during pregnancy by administering aerosolized ovalbumin or PBS control to pregnant dams at gestational days (GD)9.5, 12.5, and 17.5. Four hours after the final induction, placenta and fetal brains were collected and measured for changes in cytokines using a Luminex bead-based multiplex assay. Placental MAA tissue showed a decrease in interleukin (IL)-17 in male and female offspring. There was a sex-dependent decrease in female monocyte chemoattractant protein 1 (MCP-1). In male placentas, IL-4, C-X-C motif chemokine 10 (CXCL10)-also known as interferon γ-induced protein 10 kDa (IP-10)-and chemokine (C-C motif) ligand 5 (RANTES) were decreased. In fetal brains, elevated inflammatory cytokines were found in MAA offspring when compared to controls. Specifically, interferon-gamma (IFN-γ), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin 1α (IL-1α), IL-6, and tumor necrosis factor α (TNFα) were elevated in both males and females. In contrast, a decrease in the cytokine IL-9 was also observed. There were slight sex differences after OVA exposures. Male fetal brains showed elevated levels of macrophage inflammatory protein-2 (MIP-2), whereas female brains showed increased keratinocytes-derived chemokine (KC). In addition, IL-1𝛽 and IP-10 in male fetal brains were decreased. Together, these data indicate that repeated exposure to allergic asthma during pregnancy alters cytokine expression in the fetal environment in a sex-dependent way, resulting in homeostatic and neuroinflammatory alterations in the fetal brain.

Behavioural side effects of inhaled corticosteroids among children and adolescents with asthma

Background

Inhalation corticosteroids (ICS) are prescribed for treatment of asthma in approximately 3% of all children in Denmark. Despite limited evidence, case reports suggest that ICS-related behavioural adverse drug events (ADEs) may be frequent. In general, underreporting of ADEs to official databases is common, and little is known about doctor’s clinical experiences with behavioural ADEs when prescribing ICS for children with asthma. The objective was to investigate the extent of behavioural ADEs in children with asthma treated with ICS by comparing database findings to experiences of specialist doctors.

Methods

First, databases of the European Medicines Agency (EMA) and the Danish Medicines Agency (DKMA) were searched for reports made by healthcare professionals about behavioural ADEs in children from 2009 to 2018. Second, questionnaire data on behavioural ADEs were collected from eight of the 11 specialist doctors responsible for treating children with asthma at the six paediatric departments in Central Denmark Region and North Denmark Region.

Results

EMA and DKMA had registered 104 and 3 reports, respectively, on behavioural ADEs during the 10-year study period. In contrast, five of the eight specialist doctors (45.5%) had experienced patients who had developed behavioural changes during ICS treatment. However, none of the five specialist doctors had filed reports on these events to DKMA.

Conclusion

Behaviour-related ADEs to ICS in children with asthma are likely to be highly underreported in official databases and doctors treating children with ICS should be aware of potential ADEs and consider submitting ADE reports whenever appropriate.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02112-8.

Risk factors for asthma exacerbations during pregnancy: a systematic review and meta-analysis

BACKGROUND

Conflicting literature exists regarding the risk factors for exacerbations among pregnant women with asthma. This systematic review and meta-analysis aimed to determine risk factors for asthma exacerbations during pregnancy.

METHODS

Electronic databases were searched for the following terms: (asthma or wheeze) and (pregnan* or perinat* or obstet*) and (exacerb* or flare up or morbidit* or attack*).All studies published between 2000 and 24 August 2021 were considered for inclusion if they reported at least one potential risk factor of asthma exacerbations in pregnant women with asthma. Of the 3337 references considered, 35 publications involving 429 583 pregnant women with asthma were included. Meta-analyses were conducted to determine mean difference in risk factor between exacerbation groups, or the relative risks of exacerbation with certain risk factors. Good study quality was found through the Newcastle-Ottawa Scale (median score 8, interquartile range 7-9).

RESULTS

Increased maternal age (mean difference 0.62, 95% CI 0.11-1.13), obesity (relative risk 1.25, 95% CI 1.15-1.37), smoking (relative risk 1.35, 95% CI 1.04-1.75), black ethnicity (relative risk 1.62, 95% CI 1.52-1.73), multiparity (relative risk 1.31, 95% CI 1.01-1.68), depression/anxiety (relative risk 1.42, 95% CI 1.27-1.59), moderate-severe asthma (relative risk 3.44, 95% CI 2.03-5.83, versus mild) and severe asthma (relative risk 2.70, 95% CI 1.85-3.95, versus mild-moderate) were associated with an increased risk of asthma exacerbations during pregnancy.

CONCLUSIONS

Future interventions aimed at reducing exacerbations in pregnancy could address the modifiable factors, such as smoking and depression/anxiety, and introduce more regular monitoring for those with nonmodifiable risk factors such as obesity and more severe asthma.

Prenatal risk factors and genetic causes of ADHD in children

BACKGROUND

Attention deficit/hyperactivity disorder (ADHD) is a common disease among children; it affected 5-7% of the population in 2015. ADHD is a multifactorial disease, and its etiology is still not clearly understood.

DATA SOURCES

This narrative review has been done by searching the PubMed and Embase databases using attention deficit/hyperactivity disorder, ADHD, risk factors; genetics; pediatrics; psychiatrics as keywords.

RESULTS

ADHD is considered to be a hereditary disorder in which genes play the fundamental role in the pathogenesis; however, findings from genetic-environmental studies support the hypothesis that genetic factors can exert effects on an individual's condition by determining his/her responses to environmental exposures, especially those during the prenatal stage.

CONCLUSION

ADHD is considered as a hereditary disorder in which genes and prenatal risk factors play fundamental roles in the pathogenesis.

Association between atopic diseases and neurodevelopmental disabilities in a longitudinal birth cohort

Reports on the association between the prevalence of atopic diseases and neurodevelopmental disabilities (NDs) have been inconsistent in the literature. We investigated whether autism spectrum disorder (ASD), attention deficit-hyperactivity disorders (ADHD), and other NDs are more prevalent in children with asthma, atopic dermatitis (AD) and allergic rhinitis (AR) compared to those without specific atopic conditions. A total of 2580 children enrolled at birth were followed prospectively, of which 119 have ASD, 423 have ADHD, 765 have other NDs, and 1273 have no NDs. Atopic diseases and NDs were defined based on physician diagnoses in electronic medical records. Logistic regressions adjusting for maternal and child characteristics estimated the associations between NDs (i.e., ASD, ADHD, and other NDs) and asthma, AD and AR, respectively. Children with asthma, AD or AR had a greater likelihood of having ADHD or other NDs compared with children without specific atopic conditions. The association between ASD and asthma diminished after adjusting for maternal and child factors. Either mothers or children having atopic conditions and both mothers and children with atopic conditions were associated with a higher prevalence of ADHD in children, compared with neither mothers nor children having atopic conditions. Children diagnosed with multiple atopic diseases were more likely to have NDs compared with those without or with only one type of atopic disease. In conclusion, in this U.S. urban birth cohort, children with atopic diseases had a higher co-morbidity of NDs. The findings have implications for etiologic research that searches for common early life antecedents of NDs and atopic conditions. Findings from this study also should raise awareness among health care providers and parents about the possible co-occurrence of both NDs and atopic conditions, which calls for coordinated efforts to screen, prevent and manage NDs and atopic conditions.

Composition of the Gut Microbiota in Attention Deficit Hyperactivity Disorder: A Systematic Review and Meta-Analysis

BACKGROUND

The latest research accumulates information to explore the correlation between gut microbiota and neurodevelopmental disorders, which may lead to new approaches to treat diseases such as attention deficit/hyperactivity disorder (ADHD). However, the conclusions of previous studies are not completely consistent. The objective of the systematic review and meta-analysis was to identify evidence on the dysbiosis of gut microbiota in ADHD and find potential distinctive traits compared to healthy controls.

METHODS

Electronic databases, including PubMed, Embase, Web of Science, Cochrane Library, and PsycINFO, were searched up to August 24, 2021, using predetermined terms. Meta-analysis was performed to estimate the comparison of microbiota profiles (alpha and beta diversity) and the relative abundance of gut microbiota in ADHD patients and healthy controls.

RESULTS

A total of eight studies were included in the meta-analysis, containing 316 ADHD patients and 359 healthy controls. There was a higher Shannon index in ADHD patients than in healthy controls (SMD = 0.97; 95% CI, 0.13 to 1.82; P = 0.02; I²  = 96%), but the significance vanished after sensitivity analysis because of high heterogeneity. No significant differences in other alpha diversity indexes were found. Regarding the relative abundance of gut microbiota, the genus Blautia was significantly elevated in ADHD patients compared with controls (SMD = 0.34; 95% CI, 0.06 to 0.63; P = 0.02; I²  = 0%).

CONCLUSIONS

Patients with ADHD had gut microbiome alterations compared to healthy controls. Though more studies with strict methodology are warranted due to the high heterogeneity, further studies to translate the findings of gut microbiota dysbiosis to clinical application in ADHD patients are needed and may guide targeted therapies.

SYSTEMATIC REVIEW REGISTRATION

[https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=273993], identifier PROSPERO (CRD42021273993).

Developmental disorders in school children are related to allergic diseases

BACKGROUND

In children, relationships between developmental disorders such as attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorder and allergic diseases remain controversial, because these diseases show age- and sex-related differences. A proper understanding of the relationships between developmental disorders and allergic diseases should improve medical care for both diseases. We confirmed the prevalence of allergic diseases in elementary school-age children with developmental disorders by grade and sex.

METHODS

The subjects were 446 lower grade and 312 upper grade elementary school-age children who had visited our hospital. The prevalence of allergic diseases among subjects with and without developmental disorders by grade and sex was examined using the diagnostic names on medical records.

RESULTS

The prevalence of allergic diseases was significantly higher in lower grade boys and girls with developmental disorders than in those without developmental disorders (boys: OR 3.22, 95%; CI 1.49-6.95; girls: OR: 3.87, 95% CI: 1.27-11.82). The prevalence of allergic diseases was significantly higher in higher grade boys with developmental disorders than in those without developmental disorders (OR: 3.46, 95% CI: 1.59-7.53). Multiple logistic regression analysis in lower grades revealed that ADHD correlated with bronchial asthma (adjusted OR: 3.72, 95% CI: 1.42-9.69) and that autism spectrum disorder correlated with atopic dermatitis (adjusted OR: 4.26, 95% CI: 1.36-13.36). Analyses of children in the upper grades showed that ADHD correlated with atopic dermatitis (adjusted OR: 5.06, 95% CI: 1.28-20.05).

CONCLUSIONS

Elementary school-age children with developmental disorders were more likely to have allergic diseases. The types of allergic diseases related to developmental disorders differed by grade and sex.

The association of asthma, atopic dermatitis, and allergic rhinitis with peripartum mental disorders

BACKGROUND

Atopic diseases are characterized by dysregulated inflammatory response, which may incur the onset of peripartum mental disorders, but the impact remains unknown. This study examined whether and to what extent the history of atopic diseases is associated with newly onset peripartum mental disorders.

METHODS

Using population-based registries, we identified all primiparous women who gave birth to live singletons in Denmark during 1978-2016 (n = 937,422). The exposure was hospital contact due to the three major types of atopic diseases-asthma, atopic dermatitis, and allergic rhinitis-before conception. The primary outcome was any hospital contact for mental disorder during pregnancy and 1-year postpartum, which was further classified into affective disorders, neurotic, stress-related and somatoform disorders, and substance abuse. The follow-up started from the date of conception and ended at the date of the first diagnosis of mental disorders, 1-year postpartum, death, emigration, or December 31, 2016, whichever came first. Cox regression was used, adjusted for calendar year, age at childbirth, education, residence, and Charlson comorbidity index.

RESULTS

A total of 24,016 (2.6%) women received diagnosis of at least one of the three atopic diseases before conception (asthma, 1.7%; atopic dermatitis, 0.6%; and allergic rhinitis, 0.8%). Exposure to asthma, atopic dermatitis, or allergic rhinitis was associated with a 37% increased overall risk of peripartum mental disorders (hazard ratio [HR], 1.37; 95% confidence interval [CI], 1.27-1.49). Higher risks were observed among women with more frequent hospital contacts for atopic disease (HR, 1.80; 95% CI, 1.37-2.35; ≥5 times), and with recent hospital contacts for atopic disease (HR, 1.74; 95% CI, 1.48-2.06; within 2 years before conception). Specific associations were observed between asthma and neurotic, stress-related and somatoform disorders (HR, 1.40; 95% CI, 1.21-1.62), and between atopic dermatitis and substance abuse (HR, 1.62; 95% CI, 1.12-2.34).

CONCLUSIONS

History of asthma, atopic dermatitis, and allergic rhinitis before conception was associated with increased risks of peripartum mental disorders. Women who have atopic diseases before pregnancy may benefit from systematic mental health monitoring.

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.

The World Federation of ADHD International Consensus Statement: 208 Evidence-based conclusions about the disorder

BACKGROUND

Misconceptions about ADHD stigmatize affected people, reduce credibility of providers, and prevent/delay treatment. To challenge misconceptions, we curated findings with strong evidence base.

METHODS

We reviewed studies with more than 2000 participants or meta-analyses from five or more studies or 2000 or more participants. We excluded meta-analyses that did not assess publication bias, except for meta-analyses of prevalence. For network meta-analyses we required comparison adjusted funnel plots. We excluded treatment studies with waiting-list or treatment as usual controls. From this literature, we extracted evidence-based assertions about the disorder.

RESULTS

We generated 208 empirically supported statements about ADHD. The status of the included statements as empirically supported is approved by 80 authors from 27 countries and 6 continents. The contents of the manuscript are endorsed by 366 people who have read this document and agree with its contents.

CONCLUSIONS

Many findings in ADHD are supported by meta-analysis. These allow for firm statements about the nature, course, outcome causes, and treatments for disorders that are useful for reducing misconceptions and stigma.

Maternal depressive and anxiety symptoms and the risk of attention deficit hyperactivity disorder symptoms in offspring aged 17: Findings from the Raine Study

BACKGROUND

While previous studies have suggested that maternal anxiety and depressive symptoms are associated with increased risk of attention-deficit/hyperactivity disorder (ADHD) in their offspring in early and late childhood, studies exploring the risk in late adolescence are however lacking. This study aims to examine the association between maternal anxiety and depressive symptoms and the risk of ADHD symptoms in late adolescence (at age 17).

METHODS

We used data from the Raine Study. Maternal depressive and anxiety symptoms were measured when the child was 10 years of age using the Depression, Anxiety, and Stress Scale (DASS). Offspring ADHD symptoms at age 17 were assessed using the DSM-oriented scales of the child behavior checklist (CBCL). Log-binomial regression was used to explore the associations.

RESULTS

We found an increased risk of ADHD symptoms in offspring of mothers with comorbid anxiety and depressive symptoms when compared with offspring of mothers with no symptoms [RR 5.60 (95%CI 3.02-10.37)]. There was a nearly three-fold increase in the risk of ADHD symptoms in offspring of mothers with increased anxiety symptoms compared with offspring of mothers who were in the normal range [RR 2.84 (95%CI 1.18-6.83)]. No association was observed with maternal depressive symptoms.

CONCLUSION

This study found an increased risk of ADHD symptoms in the offspring of mothers with anxiety as well as comorbid anxiety and depressive symptoms but not among the offspring of mothers with depressive symptoms. Early screening and intervention for ADHD symptoms in offspring with maternal anxiety and comorbid anxiety and depressive symptoms are warranted.

Repeated allergic asthma in early versus late pregnancy differentially impacts offspring brain and behavior development

BACKGROUND

Stress during pregnancy and maternal inflammation are two common prenatal factors that impact offspring development. Asthma is the leading chronic condition complicating pregnancy and a common source of prenatal stress and inflammation.

OBJECTIVE

The goal of this study was to characterize the developmental impact of repeated allergic asthma inflammation during pregnancy on offspring behavioral outcomes and brain inflammation.

METHODS

Pregnant female C57BL/6 mice were sensitized with ovalbumin (OVA) or PBS vehicle control and then randomly assigned to receive daily aerosol exposures to the same OVA or PBS treatment during early, gestational days (GD) 2-GD9, or late pregnancy, GD10-GD17. Maternal sera were collected after the first and last aerosol induction regimen and measured for concentrations of corticosterone, anti-OVA IgE, and cytokine profiles. Juvenile male and female offspring were assessed for locomotor and social behaviors and later as adults assessed for anxiety-like, and marble burying behaviors using a series of behavioral tasks. Offspring brains were evaluated for region-specific differences in cytokine concentrations.

RESULTS

In early gestation, both PBS and OVA-exposed dams had similar serum corticosterone concentration at the start (GD2) and end (GD9) of daily aerosol inductions. Only OVA-exposed dams showed elevations in cytokines that imply a diverse and robust T helper cell-mediated immune response. Male offspring of early OVA-exposed dams showed decreases in open-arm exploration in the elevated plus maze and increased marble burying without concomitant changes in locomotor activity or social interactions. These behavioral deficits in early OVA-exposed male offspring were associated with lower concentrations of G-CSF, IL-4, IL-7, IFNγ, and TNFα in the hypothalamus. In late gestation, both PBS and OVA-exposed dams had increased corticosterone levels at the end of daily aerosol inductions (GD17) compared to at the start of inductions (GD10). Male offspring from both PBS and OVA-exposed dams in late gestation showed similar decreases in open arm exploration on the elevated plus maze compared to OVA male offspring exposed in early gestation. No behavioral differences were present in female offspring across all treatment groups. However, females of dams exposed to OVA during early gestation displayed similar reductions as males in hypothalamic G-CSF, IL-7, IL-4, and IFNγ.

DISCUSSION

The inflammatory responses from maternal allergic asthma in early gestation and resulting increases in anxiety-like behavior in males support a link between the timing of prenatal insults and sex-specific developmental outcomes. Moreover, the heightened stress responses in late gestation and concomitant dampened inflammatory response to allergic asthma suggest that interactions between the maternal immune and stress-response systems shape early life fetal programming.

The Temporal Hyper-Morbidity of Asthma and Attention Deficit Disorder: Implications for Interpretation Based on Comparison of Prospective and Cross-Sectional Population Samples

OBJECTIVE

The purpose of this study was to test the hypothesis that a significant temporal relationship exists between asthma and attention deficit hyperactivity disorder (ADHD).

METHODS

The population dataset consisted of 95,846,511 physician diagnoses for 768,460 (46% male) individuals spanning 1993-2010. Four groups were labeled as having neither Asthma nor ADHD, Asthma only, ADHD only, or both Asthma and ADHD and formed the basis of calculating the odds ratios for each sex describing the association of Asthma and ADHD by age, and, in addition, a prospective sample age (<5 years) between 1993 and 1996 was utilized to evaluate the temporal association between Asthma and ADHD.

RESULTS

There was a significant relationship between ADHD and Asthma within the age strata of the sample, one from the cohort and two from the whole sample. When both ADHD and Asthma were diagnosed in the same patients, the age was younger in both cross-sectional and prospective cohort samples. ADHD arose significantly more often after Asthma in the cross-sectional samples stratified on age and in the prospective cohort sample.

CONCLUSION

The results are consistent with previous literature where ADHD has been linked to allergic diseases, such as asthma.

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.