Association between the different duration of breastfeeding and attention deficit/hyperactivity disorder in children: a systematic review and meta-analysis

Longitudinal Associations Between Physical Health Conditions in Childhood and Attention-Deficit/Hyperactivity Disorder Symptoms at Age 17 Years

OBJECTIVE

Although evidence suggests significant cross-sectional relationships between attention-deficit/hyperactivity disorder (ADHD) and several physical health conditions, less is known about their longitudinal associations. We investigated the cumulative effect of childhood physical health conditions on ADHD symptoms at age 17 years, controlling for environmental factors, ADHD medication status, and ADHD symptoms at age 3 years.

METHOD

Using Millennium Cohort Study data (weighted n = 8,059), we assessed whether 4 physical health clusters (sensory, neurological, atopic, and cardio-metabolic) were associated with scores on the ADHD subscale from the Strengths and Difficulties Questionnaire at age 17 years. Environmental factors were grouped into 5 cumulative risk indices: prenatal, perinatal, postnatal environment, postnatal maternal well-being, and sociodemographic factors. Regression analyses determined whether each physical health cluster was associated with ADHD score while controlling for environmental factors, ADHD medication, and earlier symptoms.

RESULTS

Sensory, neurological, and cardio-metabolic clusters were all significantly associated with ADHD symptoms (β range = 0.04-0.09, p < .001). The overall model explained 2% of the variance. This rose to 21% (ΔR2 = 0.06) after adjusting for confounders. The sensory (β = 0.06) and neurological (β = 0.06) clusters remained significant (R2 = 0.21, ΔR2 = 0.06), but the cardio-metabolic cluster was no longer a significant predictor.

CONCLUSION

Sensory or neurological conditions in childhood were associated with higher ADHD symptoms aged 17 after adjustment of confounders. This was not the case for atopic or cardio-metabolic conditions. These findings have implications for the care of children with sensory/neurological conditions and future research examining ADHD etiopathophysiology.

A systematic meta-review of systematic reviews on attention deficit hyperactivity disorder

BACKGROUND

There are now hundreds of systematic reviews on attention deficit hyperactivity disorder (ADHD) of variable quality. To help navigate this literature, we have reviewed systematic reviews on any topic on ADHD.

METHODS

We searched MEDLINE, PubMed, PsycINFO, Cochrane Library, and Web of Science and performed quality assessment according to the Joanna Briggs Institute Manual for Evidence Synthesis. A total of 231 systematic reviews and meta-analyses met the eligibility criteria.

RESULTS

The prevalence of ADHD was 7.2% for children and adolescents and 2.5% for adults, though with major uncertainty due to methodological variation in the existing literature. There is evidence for both biological and social risk factors for ADHD, but this evidence is mostly correlational rather than causal due to confounding and reverse causality. There is strong evidence for the efficacy of pharmacological treatment on symptom reduction in the short-term, particularly for stimulants. However, there is limited evidence for the efficacy of pharmacotherapy in mitigating adverse life trajectories such as educational attainment, employment, substance abuse, injuries, suicides, crime, and comorbid mental and somatic conditions. Pharmacotherapy is linked with side effects like disturbed sleep, reduced appetite, and increased blood pressure, but less is known about potential adverse effects after long-term use. Evidence of the efficacy of nonpharmacological treatments is mixed.

CONCLUSIONS

Despite hundreds of systematic reviews on ADHD, key questions are still unanswered. Evidence gaps remain as to a more accurate prevalence of ADHD, whether documented risk factors are causal, the efficacy of nonpharmacological treatments on any outcomes, and pharmacotherapy in mitigating the adverse outcomes associated with ADHD.

Psychiatric Diagnoses Among HIV-Exposed and HIV-Unexposed Uninfected Children: A Danish Nationwide Cohort Study

This nationwide registry-based cohort study aimed to compare the risk of psychiatric diagnoses among HIV-exposed uninfected (HEU) children with a matched comparison group of HIV-unexposed uninfected (HUU) children, born in Denmark. We hypothesized that HEU children had an increased risk of psychiatric diagnoses and that this increased risk may differ by sex and age. All HEU children born in Denmark between year 2000 and 2020 were included. Each HEU child was matched by year of birth, maternal age at birth, and maternal immigration status to 10 HUU children. The primary outcome was risk of any psychiatric diagnosis (International Classification of Diseases, 10th Revision F00-F99). Incidence rate ratios (IRRs) were estimated using Poisson regression. Analyses stratifying by sex and age were also conducted. In total, 550 HEU children and 5500 HUU children were included. HEU children had an increased risk of any psychiatric disorder [IRR 1.45; 95% confidence interval (CI): 1.04-2.04] in the unadjusted analysis, but in the adjusted analysis, the risk was only significant for children aged 6-11 years [adjusted incidence rate ratio (aIRR) 1.93; 95% CI: 1.14-3.28]. Stratifying by sex, girls aged 6-11 years had an increased risk of any psychiatric disorder (aIRR 3.04; 95% CI: 1.27-7.28), while boys had an increased risk at age 12-20 years (aIRR 2.47; 95% CI: 1.18-5.17). In conclusion, HEU girls aged 6-11 years and HEU boys aged 12-20 years had an increased risk of any psychiatric disorder compared with HUU girls and boys, respectively. These findings highlight the importance of addressing the mental health needs of HEU children/adolescents.

Maternal iron status during pregnancy and attention deficit/hyperactivity disorder symptoms in 7-year-old children: a prospective cohort study

Evidence suggests that iron status may be linked to symptoms of childhood attention deficit/hyperactivity disorder (ADHD), but there is little data available on the relationship between iron status in pregnancy and the risk of developing ADHD. And the data that does exist is inconsistent. Our aim here is to assess the effect of maternal serum ferritin (SF) and haemoglobin (Hb) levels during pregnancy on manifestations of ADHD in children at 7 years of age. This prospective study analysed data from 1204 mother-child pairs from three Spanish cohorts participating in the INMA project. Maternal SF and Hb levels during pregnancy and other mother and child characteristics were collected. The children's ADHD behaviours were reported by their parents using Conners' Parent Rating Scale-Revised Short Form (CPRS-R:S). In the unadjusted regression analysis, maternal SF was positively associated with children's T-scores on the subscales Cognitive problems/Inattention (β: 0.63, 95%CI 0.06-1.19; p = 0.029) and ADHD index (β: 0.72, 95%CI 0.20-1.24; p = 0.007). These associations were not present after multivariate adjustment or stratification by first and second trimester of pregnancy. The Hb levels were not related to any of the CPRS-R:S subscales in unadjusted or multivariate-adjusted models. We observed no association between maternal SF or Hb levels and the risk of ADHD symptomatology (T-score ≥ 65 for CPRS-R:S subscales). Our results suggest that neither maternal SF nor Hb levels during pregnancy are related to ADHD symptoms in 7-year-old children.

The Role of Motor Coordination, ADHD-Related Characteristics and Temperament among Mothers and Infants in Exclusive Breastfeeding: A Cohort Prospective Study

Although exclusive breastfeeding is recommended for the first 6 months of life, breastfeeding rates are low. Motor skills and ADHD-related characteristics have not yet been examined as breastfeeding barriers. The aim of this study was to explore whether mothers' and infants' motor skills, mothers' ADHD-related characteristics and infants' temperament are associated with exclusive breastfeeding at 6 months after birth. Participants were 164 mothers and their infants recruited 2 days after birth. Mothers completed a demographic and delivery information questionnaire, the Infant Feeding Intentions Scale and the Iowa Infant Feeding Attitude Scale. At 6 months, mothers completed the Adult DCD (developmental coordination disorder)/Dyspraxia Checklist, the Adult ADHD (attention deficit hyperactivity disorder) Self-Report Scale Symptom Checklist-v1.1, and the Infant Characteristics Questionnaire, and provided information about their breastfeeding status. They were then divided into two groups accordingly: EBF (exclusive breastfeeding) and NEBF (non-exclusive breastfeeding). Infants were observed using the Test of Sensory Functions in Infants and the Alberta Infant Motor Scale. At 6 months, NEBF mothers reported higher prevalence of DCD (10.2% vs. 1.9%, χ2 = 5.561, p = 0.018) and ADHD (20.3% vs. 8.6%, χ2 = 4.680, p = 0.030) compared to EBF mothers. EBF infants demonstrated better motor coordination (t = 2.47, p = 0.016, d = 0.511), but no temperament differences compared to NEBF infants. Maternal DCD, ADHD and poor infant motor coordination are associated with non-exclusive breastfeeding and may become exclusive breastfeeding barriers. These findings may assist in identifying women at risk of not exclusively breastfeeding and encourage tailoring interventions for achieving higher exclusive breastfeeding rates.

Cumulative Evidence for the Association of Thrombosis and the Prognosis of COVID-19: Systematic Review and Meta-Analysis

Background

Although thrombosis events have been reported in patients with coronavirus disease 2019 (COVID-19), the association between thrombosis and COVID-19-related critical status or risk of mortality in COVID-19 has been inconsistent.

Objective

We conducted a meta-analysis of reports assessing the association between thrombosis and the prognosis of COVID-19.

Methods

The EMBASE, Ovid-MEDLINE, and Web of Science databases were searched up to December 9, 2021, and additional studies were retrieved via manual searching. Studies were included if they reported the risk of COVID-19-related critical status or COVID-19-related mortality in relation to thrombosis. The related data were extracted by two authors independently, and a random effects model was conducted to pool the odds ratios (ORs). In addition, stratified analyses were conducted to evaluate the association.

Results

Among 6,686 initially identified studies, we included 25 studies published in 2020 and 2021, with a total of 332,915 patients according to predefined inclusion criteria. The associations between thrombosis and COVID-19-related mortality and COVID-19-related critical status were significant, with ORs of 2.61 (95% CI, 1.91–3.55, p < 0.05) and 2.9 (95% CI, 1.6–5.24, p < 0.05), respectively. The results were statistically significant and consistent in stratified analyses.

Conclusions

Thrombosis is associated with an increased risk of mortality and critical status induced by COVID-19. Further prospective studies with large sample sizes are required to establish whether these associations are causal by considering more confounders and to clarify their mechanisms.

Observational studies cannot prove causality. However, autopsy studies show thrombosis events preceding COVID-19-related deaths. The results of this meta-analysis reported that thrombosis was associated with a 161% increased risk of mortality from COVID-19 and a 190% increased risk of COVID-19-related critical status. The type of thrombosis included in the original studies also seemed to be related to the results.

Breastmilk Feeding during the First 4 to 6 Months of Age and Childhood Disease Burden until 10 Years of Age

Background: Breastfeeding is recommended due to its beneficial effects on human health. However, the effect of breastfeeding on health differs, resulting in various childhood diseases. Objective: Our purpose was to investigate the association between breastfeeding at least in the first 4 months and the subsequent development of 15 certainly defined childhood diseases until 10 years of age, the all-cause hospitalization rate and growth at 6–7 years of age. Methods: Participants included propensity-score matched 188,052 children born between January 2008 and December 2009, who were followed up till 10 years of age. Data were taken from the National Investigation of birth Cohort in Korea study 2008 database. Risk ratios were obtained using a modified Poisson regression and weighted risk differences using binomial regression. Results: Compared to formula feeding, breastfeeding was associated with decreased risks of febrile convulsion, attention deficit hyperactivity disorder and autism spectrum disorder, pneumonia, acute bronchiolitis, hypertrophic pyloric stenosis, asthma, all-cause hospitalization, overweight/obesity and short stature. Exclusive breastfeeding at 4 to 6 months of age had similar results to exclusive breastfeeding over 6 months of age. Conclusions: Breastfeeding in early infancy reduces the risk for various childhood diseases, all-cause hospitalization rate, obesity, and short stature during childhood.

Do Breastfeeding History and Diet Quality Predict Inhibitory Control at Preschool Age?

Inhibitory control is the ability to control impulsive behavior. It is associated with a range of mental and physical health outcomes, including attention deficit hyperactivity disorder and substance dependence. Breastfeeding and healthy dietary patterns have been associated with better executive functions, of which inhibitory control is part. Additionally, breastfeeding has been associated with healthy dietary patterns. Following our preregistration in the Open Science Framework, we investigated the associations between breastfeeding history and inhibitory control at preschool age, with habitual diet quality as a potential mediating factor. A total of 72 families from a longitudinal study participated at child age 3. Breastfeeding questionnaires were administered at 2, 6, and 12 weeks, and at 12 and 36 months. Six inhibitory control tasks were performed during a home visit, and questionnaires were filled in by both parents. Diet quality at age 3 was assessed via three unannounced 24-h recalls. Structural equation modelling was performed in R. This study did not provide evidence that breastfeeding history is associated with inhibitory control in 3-year-old children. Furthermore, diet quality at age 3 did not mediate the link between breastfeeding history and inhibitory control. Previous studies have investigated broader aspects of inhibitory control, such as executive functions, and used different methods to assess nutritional intake, which might explain our differential findings. Our findings contribute to the growing literature on associations between nutrition and behavior. Future replications with larger and more diverse preschool samples are recommended.

DNA methylation of GFI1 as a mediator of the association between prenatal smoking exposure and ADHD symptoms at 6 years: the Hokkaido Study on Environment and Children's Health

BACKGROUND

Prenatal smoking exposure has been associated with childhood attention-deficit/hyperactivity disorder (ADHD). However, the mechanism underlying this relationship remains unclear. We assessed whether DNA methylation differences may mediate the association between prenatal smoking exposure and ADHD symptoms at the age of 6 years.

RESULTS

We selected 1150 mother-infant pairs from the Hokkaido Study on the Environment and Children's Health. Mothers were categorized into three groups according to plasma cotinine levels at the third trimester: non-smokers (≤ 0.21 ng/mL), passive smokers (0.21-11.48 ng/mL), and active smokers (≥ 11.49 ng/mL). The children's ADHD symptoms were determined by the ADHD-Rating Scale at the age of 6 years. Maternal active smoking during pregnancy was significantly associated with an increased risk of ADHD symptoms (odds ratio, 1.89; 95% confidence interval, 1.14-3.15) compared to non-smoking after adjusting for covariates. DNA methylation of the growth factor-independent 1 transcriptional repressor (GFI1) region, as determined by bisulfite next-generation sequencing of cord blood samples, mediated 48.4% of the total effect of the association between maternal active smoking during pregnancy and ADHD symptoms. DNA methylation patterns of other genes (aryl-hydrocarbon receptor repressor [AHRR], cytochrome P450 family 1 subfamily A member 1 [CYP1A1], estrogen receptor 1 [ESR1], and myosin IG [MYO1G]) regions did not exert a statistically significant mediation effect.

CONCLUSIONS

Our findings demonstrated that DNA methylation of GFI1 mediated the association between maternal active smoking during pregnancy and ADHD symptoms at the age of 6 years.