Shared genetic influences do not explain the association between parent-offspring relationship quality and offspring internalizing problems: results from a Children-of-Twins study.

BACKGROUND: Associations between parenting and child outcomes are often interpreted as reflecting causal, social influences. However, such associations may be confounded by genes common to children and their biological parents. To the extent that these shared genes influence behaviours in both generations, a passive genetic mechanism may explain links between them. Here we aim to quantify the relative importance of passive genetic v. social mechanisms in the intergenerational association between parent-offspring relationship quality and offspring internalizing problems in adolescence. METHODS: We used a Children-of-Twins (CoT) design with data from the parent-based Twin and Offspring Study of Sweden (TOSS) sample [909 adult twin pairs and their offspring; offspring mean age 15.75 (2.42) years], and the child-based Swedish Twin Study of CHild and Adolescent Development (TCHAD) sample [1120 adolescent twin pairs; mean age 13.67 (0.47) years]. A composite of parent-report measures (closeness, conflict, disagreements, expressions of affection) indexed parent-offspring relationship quality in TOSS, and offspring self-reported internalizing symptoms were assessed using the Child Behavior Checklist (CBCL) in both samples. RESULTS: A social transmission mechanism explained the intergenerational association [r = 0.21 (0.16-0.25)] in our best-fitting model. A passive genetic transmission pathway was not found to be significant, indicating that parental genetic influences on parent-offspring relationship quality and offspring genetic influences on their internalizing problems were non-overlapping. CONCLUSION: These results indicate that this intergenerational association is a product of social interactions between children and parents, within which bidirectional effects are highly plausible. Results from genetically informative studies of parenting-related effects should be used to help refine early parenting interventions aimed at reducing risk for psychopathology.

Early inherited risk for anxiety moderates the association between fathers' child-centered parenting and early social inhibition.

Studies of the role of the early environment in shaping children's risk for anxiety problems have produced mixed results. It is possible that inconsistencies in previous findings result from a lack of consideration of a putative role for inherited influences moderators on the impact of early experiences. Early inherited influences not only contribute to vulnerabilities for anxiety problems throughout the lifespan, but can also modulate the ways that the early environment impacts child outcomes. In the current study, we tested the effects of child-centered parenting behaviors on putative anxiety risk in young children who differed in levels of inherited vulnerability. We tested this using a parent-offspring adoption design and a sample in which risk for anxiety problems and parenting behaviors were assessed in both mothers and fathers. Inherited influences on anxiety problems were assessed as anxiety symptoms in biological parents. Child-centered parenting was observed in adoptive mothers and fathers when children were 9 months old. Social inhibition, an early temperament marker of anxiety risk, was observed at child ages 9 and 18 months. Inherited influences on anxiety problems moderated the link between paternal child-centered parenting during infancy and social inhibition in toddlerhood. For children whose birth parents reported high levels of anxiety symptoms, greater child-centered parenting in adoptive fathers was related to greater social inhibition 9 months later. For children whose birth parents reported low levels of anxiety symptoms, greater child-centered parenting in adoptive fathers was related to less social inhibition across the same period.

The relationship between parental depressive symptoms and offspring psychopathology: evidence from a children-of-twins study and an adoption study.

BACKGROUND: Parental depressive symptoms are associated with emotional and behavioural problems in offspring. However, genetically informative studies are needed to distinguish potential causal effects from genetic confounds, and longitudinal studies are required to distinguish parent-to-child effects from child-to-parent effects. METHOD: We conducted cross-sectional analyses on a sample of Swedish twins and their adolescent offspring (n = 876 twin families), and longitudinal analyses on a US sample of children adopted at birth, their adoptive parents, and their birth mothers (n = 361 adoptive families). Depressive symptoms were measured in parents, and externalizing and internalizing problems measured in offspring. Structural equation models were fitted to the data. RESULTS: Results of model fitting suggest that associations between parental depressive symptoms and offspring internalizing and externalizing problems remain after accounting for genes shared between parent and child. Genetic transmission was not evident in the twin study but was evident in the adoption study. In the longitudinal adoption study child-to-parent effects were evident. CONCLUSIONS: We interpret the results as demonstrating that associations between parental depressive symptoms and offspring emotional and behavioural problems are not solely attributable to shared genes, and that bidirectional effects may be present in intergenerational associations.

Observation of feeding in the diagnosis of posttraumatic feeding disorder of infancy.

OBJECTIVES: To delineate diagnostic criteria for posttraumatic feeding disorder (PTFD) of infancy and to differentiate PTFD from infantile anorexia (IA) via observation of feeding interactions. METHOD: Three groups of infants (aged 6-32 months) participated: PTFD (n = 30), IA (n = 30), and healthy eater controls (n = 30). The three groups were matched with regard to age, gender, ethnicity, and socioeconomic status. Child psychiatrists used infants' medical and feeding histories and observed 20-minute mother-infant feeding interactions to determine diagnoses and group placement. Feeding interactions were also videotaped, and two raters assessed infants' resistance to feeding situations and to swallowing, as well as specific qualities of mother-infant feeding interactions. RESULTS: Overall, the clinical groups (PTFD and IA) demonstrated more problematic feeding interactions than did the control group. However, the PTFD group exhibited more resistance during feeding interactions than did the other two groups. In particular, the PTFD group displayed the most resistance to swallowing food. CONCLUSIONS: Infants' medical and feeding histories, as well as observations of feeding, are important to making the diagnosis of PTFD and differentiating it from other feeding disorders. Implications for treatment of PTFD are discussed.

Maternal characteristics and toddler temperament in infantile anorexia.

OBJECTIVE: To explore the association between specific maternal characteristics, maternal perceptions of toddler temperament, and infantile anorexia. METHOD: Three groups of toddlers (aged 12-37 months) participated in this study: toddlers with infantile anorexia (n = 34), picky eaters (n = 34), and healthy eaters (n = 34). Mothers completed questionnaires that assessed their own eating attitudes, marital satisfaction, and their toddlers' temperament, and an interview that explored their attachment representations. Mothers and toddlers were videotaped during a feeding session, and toddlers were weighed and measured. RESULTS: Temperament ratings differentiated between infantile anorexics and healthy eaters (p < .0001), with infantile anorexics receiving higher difficulty, irregularity, negativity, dependence, and unstoppable ratings. Mothers of anorexics showed greater attachment insecurity than mothers of healthy eaters (p < .05), but they demonstrated neither overt eating pathology nor less marital satisfaction than the other groups. Thirty-nine percent of variance in feeding conflict was explained by toddlers' diagnoses, temperament ratings, and maternal characteristics. Twenty-one percent of variance in toddlers' weights was explained by temperament ratings and feeding conflict. CONCLUSION: Maternal characteristics and perceptions of their toddlers' temperament characteristics should be addressed in treatment for infantile anorexia.

Negative reactivity and attachment: Down syndrome's contribution to the attachment-temperament debate.

This longitudinal study investigated the relation between negative reactivity and attachment in children with Down syndrome (DS). Specifically, we examined whether extremely low negative reactivity is associated with the enactment and organization of attachment behaviors. To address this issue 30 infants with DS (13 female, 17 male) were observed in Ainsworth's Strange Situation at 19 and 27 months. The intensity and duration of distress reactions were coded in 15-s intervals throughout each Strange Situation episode. Children's distress intensity during separations from caregivers was used to place children into Low versus Moderate/High Negative Reactivity groups. In addition, ratings of infants' social interactive behaviors (contact maintenance, proximity seeking, distance interaction, resistance, and avoidance) were made for each episode and used to assess the quality of infants' attachment relationships. The data indicated that there are high rates of Type A and D insecure attachments within the DS population at each age studied. However, low negative reactivity was not consistently related to the activation of the attachment behavioral system, or associated with insecure attachment relationships. Alternative explanations for the high rate of insecure attachments are discussed.

Attachment and feeding problems: a reexamination of nonorganic failure to thrive and attachment insecurity.

OBJECTIVE: To examine the relationship between attachment patterns, degree of security, and feeding problems. METHOD: Three groups of toddlers (age range = 12-37 months) were included: toddlers with infantile anorexia (n = 33), picky eaters (n = 34), and healthy eaters (n = 34). Participants in each group were matched for age, socioeconomic status, gender, and ethnicity. Attachment patterns and degree of attachment security were assessed through the Ainsworth Strange Situation. RESULTS: The infantile anorexia group exhibited a higher rate of insecure attachment relationships than the picky eater and healthy eater groups. When measured on a continuous scale, the infantile anorexia group also displayed a higher degree of insecurity than the other groups. Contrary to previous research, elevated rates of type D attachments were not present within the infantile anorexia group. CONCLUSIONS: Feeding problems and growth deficiencies can occur within the context of organized and secure attachment child-parent relationships. However, insecure attachment relationships may intensify feeding problems and may lead to more severe malnutrition. Implications for the treatment of specific feeding problems are discussed.

Diagnosing infantile anorexia: the observation of mother-infant interactions.

OBJECTIVE: This study has three objectives: (1) to delineate the diagnostic criteria for infantile anorexia, including the onset of persistent food refusal during the infant's transition to spoon- and self-feeding, acute and/or chronic malnutrition, parental concern about the infant's poor food intake, and mother-infant conflict, talk, and distraction during feeding; (2) to determine the interrater agreement of child psychiatrists when diagnosing infantile anorexia based on these criteria; and (3) to describe the use of the Feeding Scale as a diagnostic tool. METHOD: One hundred two toddlers, ranging in age from 12 to 37 months, were assessed by two child psychiatrists and assigned the diagnosis of infantile anorexia, picky eater, or good eater. In addition, observers who were masked to the toddler's diagnosis rated mother-infant interactions with the Feeding Scale to permit objective evaluation of those interactions. RESULTS: Two child psychiatrists were able to assign toddlers to infantile anorexia, picky eating, and healthy, good eating groups with a high level of agreement. The objective scale for rating mother-infant interactions showed a high level of agreement between two masked raters and a good level of agreement between masked raters and the child psychiatrists' diagnostic assessment. CONCLUSIONS: Infantile anorexia can be diagnosed with high reliability by child psychiatrists. Evaluation of mother-infant interactions is a useful diagnostic tool.