The marriage-related risk factors during maternal pregnancy in children with attention-deficit hyperactivity disorder

Prenatal maternal stress and risk of neurodevelopmental disorders in the offspring: a systematic review and meta-analysis

PURPOSE

Exposure to prenatal stress has been reported to affect the risk of adverse neurodevelopmental outcomes in the offspring; however, there is currently no clear consensus. The aim of this systematic review and meta-analysis was to examine the existing literature on the association between prenatal stress and autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD) in the offspring.

METHODS

Based on a registered protocol, we searched several electronic databases for articles in accordance with a detailed search strategy. We performed this study following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA).

RESULTS

Prenatal stress was significantly associated with an increased risk of both ASD (pooled OR 1.64 [95% CI 1.15-2.34]; I² = 90%; 15 articles) and ADHD (pooled OR 1.72 [95% CI 1.27-2.34]; I² = 85%; 12 articles).

CONCLUSIONS

This study suggests that prenatal stress may be associated with ASD and ADHD; however, several limitations in the reviewed literature should be noted including significant heterogeneity and there is a need for carefully controlled future studies in this area.

Adverse family life events during pregnancy and ADHD symptoms in five-year-old offspring

BACKGROUND

Prenatal exposure to maternal adverse life events has been associated with offspring ADHD, but the role of familial confounding is unclear. We aimed to clarify if adverse life events during pregnancy are related to ADHD symptoms in offspring, taking shared familial factors into account.

METHOD

Data were collected on 34,751 children (including 6,427 siblings) participating in the population-based Norwegian Mother and Child Cohort Study. During pregnancy, mothers reported whether they had experienced specific life events. We assessed ADHD symptoms in five-year-old children with the Conners' Parent Rating Scale-Revised: short form. We modeled the associations between life events and mean ADHD scores with ordinary linear regression in the full cohort, and with fixed-effect linear regression in sibling comparisons to adjust for familial confounding.

RESULTS

Children exposed to adverse life events had higher ADHD scores at age 5, with the strongest effect observed for financial problems (mean differences 0.10 [95% CI: 0.09, 0.11] in adjusted model), and the weakest for having lost someone close (0.02 [95% CI 0.01, 0.04] in adjusted model). Comparing exposure-discordant siblings resulted in attenuated estimates that were no longer statistically significant (e.g. mean difference for financial problems -0.03 [95% CI -0.07, 0.02]). ADHD scores increased if the mother had experienced the event as painful or difficult, and with the number of events, whereas sibling-comparison analyses resulted in estimates attenuated toward the null.

CONCLUSIONS

These results suggest that the association between adverse life events during pregnancy and offspring ADHD symptoms is largely explained by familial factors.

Prenatal programming of mental illness: current understanding of relationship and mechanisms

The British epidemiologist Dr. David J. Barker documented the relationship between infant birth weight and later onset of hypertension, coronary heart disease, insulin resistance, and type II diabetes. A stressful in utero environment can cause long-term consequences for offspring through prenatal programming. Prenatal programming most commonly occurs through epigenetic mechanisms and can be dependent on the type and timing of exposure as well as the sex of the fetus. In this review, we highlight the most recent evidence that prenatal programming is implicated in the development of psychiatric disorders in offspring exposed to maternal stress during pregnancy. Methodological differences between studies contribute to unavoidable heterogeneity in study findings. Current data suggest that fetal exposure to maternal hypothalamic-pituitary-adrenal axis dysregulation, excessive glucocorticoids, and inflammation with resulting epigenetic changes at both the placental and fetal levels are important areas of continued investigation.

Disruptive behaviour disorders: a systematic review of environmental antenatal and early years risk factors

Disruptive behaviour disorders (DBDs), including attention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD) and conduct disorder (CD) are chronic disorders with significant overlap in aetiology and presentation. An integrative examination of environmental risk factors is lacking. Six literature searches of web-based bibliographic databases were completed to identify literature on DBDs in general and five disorders in particular: CD, ODD, ADHD, deficits of attention, motor control and perception, and reactive attachment disorder. Searches were filtered to focus on studies including diagnostic assessment, focussing on environmental risk and protective factors in the first 4 years of life. The database searches generated 9806 papers of which 47 were reviewed after filters had been applied. The evidence suggests links between a number of early life risk factors and DBDs, including prenatal cigarette smoking and alcohol use, prenatal viral illness, maternal stress and anxiety, low birthweight, peri-partum and early neonatal complications, parental stress and parenting styles in infancy, early deprivation, adoption and separation. Despite the understanding that there is sharing of risk factors between the DBDs, there has been a disproportionate focus on the role of certain risk factors at the expense of others and the field is weakened by difficulties in controlling for all potential confounding variables.

Relationship between symptoms of attention-deficit/hyperactivity disorder and family functioning: a community-based study

This study examined the relationship between family functioning and attention-deficit/hyperactivity disorder (ADHD) symptoms in an Australian community-based sample. Children were screened for ADHD in their second year of formal schooling. Two hundred and two (202) primary caregivers completed validated measures of family quality of life (QoL), parent mental health, parenting styles and parental relationship quality. Compared with controls, parents of children screening positive for ADHD reported poorer family QoL in the domains of emotional impact (mean difference [MD] -20.1; 95% CI -38.2 to -1.9, p = 0.03) and impact on family activities (MD -17.2; 95% CI -27.9 to -6.5, p = 0.002), less parental warmth (MD -3.4; 95% CI -6.0 to -0.9, p = 0.01) and higher parental depression (MD 6.8; 95% CI 1.8 to 11.7, p = 0.009) and anxiety (MD 6.2; 95% CI 1.7 to 10.6, p = 0.008) after adjusting for socio-demographic characteristics and child conduct symptoms. Parents of children screening positive for ADHD reported higher stress (MD 4.5; 95% CI 1.2 to 7.1, p = 0.007) and more inconsistent (MD 3.0; 95% CI 1.2 to 4.8, p = 0.002) and hostile (MD = 2.2; 95% CI 1.0 to 3.4, p = 0.001) parenting after adjusting for socio-demographic factors only. No difference in parental relationship quality and parental inductive reasoning was identified.

CONCLUSION

These findings suggest a strong association between poor family functioning and ADHD symptoms and carry implications for comprehensive ADHD management and the importance of seeing the child within the family context.

Prenatal Maternal Stress Associated with ADHD and Autistic Traits in early Childhood

Research suggests that offspring of mothers who experience high levels of stress during pregnancy are more likely to have problems in neurobehavioral development. There is preliminary evidence that prenatal maternal stress (PNMS) is a risk factor for both autism and attention deficit hyperactivity disorder (ADHD), however most studies do not control for confounding factors and no study has investigated PNMS as a risk factor for behaviors characteristic of these disorders in early childhood. A population cohort of 2900 pregnant women were recruited before their 18th week of pregnancy and investigated prospectively. Maternal experience of stressful life events was assessed during pregnancy. When offspring were age 2 years, mothers completed the child behavior checklist. Multiple regression showed that maternal stressful events during pregnancy significantly predicted ADHD behaviors in offspring, after controlling for autistic traits and other confounding variables, in both males (p = 0.03) and females (p = 0.01). Similarly, stressful events during pregnancy significantly predicted autistic traits in the offspring after controlling for ADHD behaviors and confounding variables, in males only (p = 0.04). In conclusion, this study suggests that PNMS, in the form of typical stressful life events such as divorce or a residential move, show a small but significant association with both autistic traits and ADHD behaviors independently, in offspring at age 2 years, after controlling for multiple antenatal, obstetric, postnatal, and sociodemographic covariates. This finding supports future research using epigenetic, cross-fostering, and gene–environment interaction designs to identify the causal processes underlying this association.