Families with ADHD children report more negative family relationships than families without ADHD. Questions remain about the genetic factors underlying the association between family relationships and ADHD in children, as well as the impact of ADHD symptoms. The present study, which used two genetically sensitive designs, examined the associations between biologically and non-biologically associated maternal ADHD symptoms, child impulsivity and activation, as well as child ADHD symptoms. The study designs enable assessing associations by controlling passive genotype-environment correlations and directly examining evocative gene-environment correlates.
Methods
A cross-sectional adoption-at-conception design (Cardiff IVF Study; C-IVF) and a longitudinal adoption-at-birth design (Early Growth and Development Study; EGDS) were used. The C-IVF sample consisted of 160 mothers and children (aged 5 to 8 years). The EGDS consisted of 320 sets (age 6 years) of biologically and adoptively related mothers and their children. Adoptive questionnaires assessed maternal ADHD symptoms, parenting, child impulsivity, activation, and ADHD symptoms. Father’s reports are used to compare maternal behavior with child ADHD symptoms.
Results
Both samples showed significant associations between the mother’s ADHD, hostile parenting behavior, and the child’s ADHD. Passive rGE, which could explain these associations, was eliminated because both samples consisted of genetically non-related mothers and their children. Further, path analysis revealed evidence for evocative rGE processes in the longitudinal adoption-at-birth study (EGDS) from biologically-related maternal ADHD symptoms to biologically-unrelated maternal hostile parenting through early disrupted child behavior (impulsivity/activation), with hostile maternal parenting and disrupted child behavior associated with later child ADHD symptoms, controlling for concurrent adoptive mother ADHD symptoms.
The Developmental Interface between Nature and Nurture: A Review of Biological Mother Influences and Child ADHD Symptoms
It is well known that Attention Deficit/Hyperactivity Disorder (ADHD) is highly heritable, whether it is defined like all psychopathologies. But non-inherited factors also play a part (Lifford). Harold and Thapar HTML It is difficult to determine the environmental factors that are causally responsible for ADHD symptoms (Thapar Elam Lewis Rice). Families and, in particular, hostile parenting are linked to different types of psychopathology. Harold, it is not clear whether some family conditions, such as hostile parental behavior, have an adverse or dangerous effect on ADHD. Two primary explanations: The relationship between family relationships in children and ADHD symptoms may be explained by the genes parents share with their biologically related children. This could be due to the fact that ADHD symptoms in children affect family relationships, not vice versa. Rarely have studies used research designs that allow environmental and genetic factors to be separated. This allows the study of child-on-parent effects.
Families have a major impact on ADHD symptoms in children.
Numerous research designs have demonstrated that genetic and family Relationships influence the course and severity of ADHD symptoms in children. There are classic twin designs, such as Burthe009 (the association between hostile parental-child relations and ADHD has been demonstrated in both clinical and pop studies). Studies. These include longitudinal and treatment studies. (See HTML0) Treatment and longitudinal research have shown that ADHD symptoms can lead to hostile parent-child relationships. There are few studies in this area that have considered child-on-parent effects and controlled for inherited confounders. In a series of studies conducted in an orphanage in Romania using a quasi-experimental approach, it was found that children who experienced extreme but rare forms of adversity had a higher risk of ADHD symptoms as well as pseudo-autistic characteristics (Stevens et al., Sonuga Barke & Asherson, 2006).
The majority of research on the impact of family relationships on child outcomes is conducted with biologically related children and mothers. It is difficult to tell from these studies whether the association between family-level variables (e.g., parenting) and child outcomes, such as ADHD, is a result of shared genetic influences or environmental effects (Plomin, DeFries, & Loehlin, 1977). In biological families, the relationship between parent characteristics and child characteristics may be due to genetic factors that influence both parent traits and child characteristics. Genes can influence not only psychopathology indexes (e.g., ADHD) but also the environment in which children are raised. This overlap of influence is called genotype-environment (GE).
Traditional Approaches to Examining Genotype-Environment Correlation
In previous research, both the passive and the evocative rGE have been highlighted by twin designs (Horwitz and Neiderhiser 2011) and their variant, the children of twins design (D’Onofrio 2005). Caspi et al. (2004) suggest that passive rGE cannot explain the association between parenting characteristics, adolescent behavior, and antisociality. Passive GE, particularly in parenting and child adjustment, is not ruled out by most genetically informed research. Examining evocative rGE has been facilitated by longitudinal designs where genetically-influenced twin behaviors predict later parenting. This design showed evocative relationships between hostile parenting by mothers and the temperament and behavior of toddlers (Forget Dubois & colleagues, 2007). The twin studies of older adolescents or children have also shown evidence of passive effects and evocative ones that are responsible for the associations between family relationships and child outcomes.
CoT and extended CoT designs provide evidence of passive rGE. In one study, Lynch et al. (2006) found that harsh punishments had an environmental component. This was the cause of externalizing behavior in children. There is also an evocative relationship in adolescents between internalizing problems and excessive maternal emotion. (Narusyte et al., 2008) And externalizing behaviors and criticism by mothers. (Narusyte et al., 2011). The twin study and its derivatives provide important insights into the relative roles of passive and evocative child behavior. The twin study relies on genetically related samples from both parents and children. It is possible to estimate the genetic and environmental contributions that underlie this association. It is not possible, however, to separate non-genetic and genetic factors.
Natural Experimental Research Designs: Benefits and Usages
Research designs that separate passive rGE from family relationships and child outcome associations and allow examination of evocative rGE can improve understanding of the relationship between family interaction and child development. This unique opportunity is accommodated by two complementary study designs. The first study is an adoption-at-birth design with a sample of families with domestic infant adoptions; the second study is an adoption-at-conception design using a sample of families with children conceived through in vitro fertilization (IVF). Both studies allow for the examination of the relationship between family relationships, child outcomes, and the confounding effects of passive rGE. The first study provides an opportunity to examine the evocative process of rGE.
Genetic relationships between children conceived by assisted reproduction technology can be between the parents (homologous), the mother only (sperm donation), the father only (egg donation), or neither (embryo donation). In a third case, both parents share a genetic connection with the child, but a surrogate who is not related provides the baby’s intrauterine environment. The current study is focused on mothers who are not genetically related to their children (egg or embryo donation). It, therefore, constitutes an adoption-at-conception design because rearing mothers undergo gamete “adoption” prenatally.
The current study
The present study examined associations between maternal hostility and child ADHD symptoms using a cross-sectional, rearing mother-focused adoption-at-conception design (the Cardiff IVF Study; C-IVF) and a longitudinal adoption-at-birth design (the Early Growth and Development Study; EGDS). Initial analyses investigated associations between maternal hostility and child ADHD symptoms as well as raising a mother who has ADHD, using both study designs. All analyses were conducted with passive and active controls. Additional analyses, using the longitudinal EGDS adopt-at-birth design, examined the relationship between biologically related behavior problems in children (impulsivity and activated behaviors, consistent with early ADHD types of behaviors) aged 4.5 years. They also looked at the relationship between child impulsivity (and activation) and child ADHD symptoms at six years of age.