Serotonin transporter polymorphism moderates the effects of caregiver intrusiveness on ADHD symptoms among institutionalized preschoolers

The Loudness Dependence of Auditory Evoked Potentials is associated with the Symptom Severity and Treatment in Boys with Attention Deficit Hyperactivity Disorder

Objective

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Individual differences in sensitivity to positive home environment among children "at risk" for attention-deficit/hyperactivity disorder: A review

Although the evidence for the genetic basis of attention-deficit/hyperactivity disorder (ADHD) is strong, environmental factors, such as the quality of parenting or the home environment, may moderate such genetic liability. The plausible negative effect of a low-quality home environment and negative parenting on child outcomes is well-established; however, the positive effect of a high-quality environment and positive parenting remained largely uninvestigated. Due to the presence of genetic, temperamental, or physiological factors, children who were traditionally considered at-risk for ADHD may be more sensitive to aspects of their environment compared to children who are not at such risk. Therefore, they would be more affected by their environmental experience, either for good or bad. Under supportive environmental conditions, such at-risk individuals might actually outperform their non-vulnerable peers, suggesting that these individual factors might be considered susceptibility factors rather than risk factors. Little is known regarding the positive effect of the environment in the ADHD literature, but it has been demonstrated in cognitive functions that are closely associated with ADHD, such as executive functions (EF). We review this literature and examine the extant empirical support for sensitivity to aspects of the home environment and parenting in the case of ADHD and EF. Moreover, we review factors that could help identify the specific aspects of the home environment and parenting that these children might be more susceptible to. Such knowledge could be valuable when designing preventive interventions and identifying those children that are especially sensitive and could benefit from such interventions. Recommendations for future studies are discussed as well.

Longitudinal Influences of DRD4 Polymorphism and Early Maternal Caregiving on Personality Development and Problem Behavior in Middle Childhood and Adolescence

Most studies examining gene-environment effects on self-regulation focus on outcomes early childhood or adulthood. However, only a few studies investigate longitudinal effects during middle childhood and adolescence and compare two domains of early caregiving. In a longitudinal follow-up with a sample of N = 87, we studied the effects of differences in the DRD4 tandem repeat polymorphisms and two domains of early maternal caregiving quality on children's personality development using Block's California Child Q-Set (CCQ) at age six and age 12 and on problem behavior at ages six and seven. Early maternal regulation quality predicted later ego-resiliency and aggressiveness. In addition, significant gene-environment interactions revealed that children with the 7+ DRD4 tandem repeat polymorphism and poor maternal regulation quality in infancy showed lower scores in ego-resiliency and higher scores in ego-undercontrol and CCQ aggressiveness. In contrast, children who had experienced effective maternal regulation in infancy showed a comparable level in personality traits and problem behavior as the DRD4 7- group independent of the levels of maternal regulatory behavior. Similarly, longitudinal caregiving × DRD4 interactions were found for behavior problems in middle childhood, especially for oppositional-aggression, inattentive-hyperactivity, and social competence. Early caregiving effects were only found for maternal regulation quality, but not for maternal responsiveness. Effective early maternal regulation in infancy can moderate the negative effect of DRD4 7+ on children's self-regulation in middle childhood and adolescence. However, maternal responsiveness has no comparable effects. It seems relevant to consider several dimensions of early caregiving and to also measure the environment in more detail in gene-environment studies.

Temperament moderates the effects of early deprivation on infant attention

Institutional care has been shown to increase the risk of attention problems in children, but some children are more sensitive to their environment, both for better and for worse. With this in mind, the current study examined the moderating role of temperament (falling reactivity) between early adversity and attention skills. Six- to 15-month-old infants residing in institutions (n = 63) and infants reared by their biological families from low socioeconomic environments (n = 59) were recruited. The infants' attention skills were measured by calculating the length of time they spent looking at toys. The infants' temperaments were measured by a subscale of the Infant Behavior Questionnaire (falling reactivity/rate of recovery from distress). The findings were in line with the differential susceptibility theory. Compared to infants with high levels of falling reactivity, infants with lower levels of falling reactivity had better attention skills if they were in a family group, but they had lower attention skills if they were residing in institutions. The attention skills of the infants who had higher scores for falling reactivity did not appear to be affected by the adverse environment.

Early life predictors of attention deficit/hyperactivity disorder symptomatology profiles from early through middle childhood

This study used repeated measures data to identify developmental profiles of elevated risk for ADHD (i.e., six or more inattentive and/or hyperactive-impulsive symptoms), with an interest in the age at which ADHD risk first emerged. Risk factors that were measured across the first 3 years of life were used to predict profile membership. Participants included 1,173 children who were drawn from the Family Life Project, an ongoing longitudinal study of children's development in low-income, nonmetropolitan communities. Four heuristic profiles of ADHD risk were identified. Approximately two thirds of children never exhibited elevated risk for ADHD. The remaining children were characterized by early childhood onset and persistent risk (5%), early childhood limited risk (10%), and middle childhood onset risk (19%). Pregnancy and delivery complications and harsh-intrusive caregiving behaviors operated as general risk for all ADHD profiles. Parental history of ADHD was uniquely predictive of early onset and persistent ADHD risk, and low primary caregiver education was uniquely predictive of early childhood limited ADHD risk. Results are discussed with respect to how changes to the age of onset criterion for ADHD in DSM5 may affect etiological research and the need for developmental models of ADHD that inform ADHD symptom persistence and desistance.

Gene-Environment Interactions in Psychiatry: Recent Evidence and Clinical Implications

PURPOSE OF REVIEW

We identify the recent evidence for gene-by-environment interaction studies in relation to psychiatric disorders. We focus on the key genotypic data as well as environmental exposures and how they interact to predict psychiatric disorders and psychiatric symptomatology. We direct our focus on the psychiatric outcomes that were focused on by the Psychiatric Genetics Consortium.

RECENT FINDINGS

Many of the studies focus on candidate gene approaches, with most of the studies drawing upon previous literature to decide the genes of interest. Other studies used a genome-wide approach. While some studies demonstrated positive replication of previous findings, replication is still an issue within gene-by-environment interaction studies. Gene-by-environment interaction research in psychiatry globally suggests some susceptibility to environmental exposures based on genotype; however, greater clarity is needed around the idea that genetic risk may not be disorder specific.

[Research advances in pathogenesis of attention deficit hyperactivity disorder]

Both of genetic and environmental factors play important roles in the pathogenesis of attention deficit hyperactivity disorder (ADHD), and genetic factors can increase the susceptibility of individuals to environmental risk factors. There are extensive and various structural and functional abnormalities of the brain in patients with ADHD. Given the close functional relationship between brain areas, exploration has also been expanded to the dysfunction of brain network in recent years. As for the biochemical mechanism underlying ADHD, monoamine neurotransmitters are still most valued, and abnormalities of brain-derived neurotrophic factors and glutamic acid/γ-aminobutyric acid imbalance may also be present. Due to the abnormal neuroendocrine function and connectivity between brain areas caused by the synergistic effect of genetic and environmental factors, the prefrontal cortex loses control of the lower brain areas, so that the basal ganglia and amygdala affect normal behavioral and emotional reactions. Dysfunction of the endocrine axes may further aggravate neuroendocrine disorder. The above process may eventually lead to changes in brain structure and function, which may be associated with the development of ADHD. However, considering the heterogeneity of ADHD, its pathological process may not be the same, and the exact mechanism needs to be further clarified.

Recent contributions for understanding Inhibited Reactive Attachment Disorder

This special issue brings together studies representing the current state of the art research on inhibited reactive attachment disorder (RAD) from developmental psychology and developmental attachment research. This editorial introduces and discusses conceptual topics of the development and  the assessment of inhibited RAD. Next, five empirical studies of this special issue cover timely topics from developmental trajectories and longitudinal stability of RAD to associations with caregiving experiences in institutions, IQ, and psychopathology, moreover aspects of internal working models of children with inhibited RAD are examined. The commentary meta-analytically integrates the empirical evidence of all five studies and offers theoretically derived suggestions for further research. In this editorial, we discuss unsettled issues and future directions for attachment oriented research in this field.

Testing an Attachment-Based Parenting Intervention-VIPP-FC/A in Adoptive Families with Post-institutionalized Children: Do Maternal Sensitivity and Genetic Markers Count?

This study investigated the effectiveness of a newly integrated version of an intervention targeting adoptive mothers' positive parenting for promoting children's emotional availability, by testing the moderating role of both two maternal genetic polymorphisms (i.e., 5HTTLPR and DRD4-VNTR) and emotional availability-EA on intervention outcomes. Mothers with their children (N = 80; Mage = 42.73 years, SD = 3.79; Mage = 33.18 months, SD = 16.83 months) participated in a RCT testing the Video-Feedback Intervention to Promote Positive Parenting and Sensitive Discipline-VIPP-FC/A effectiveness. Mixed effects regression models showed a significant improvement in mother-child EA for the VIPP-intervention vs. the dummy intervention condition, with a moderating role of maternal EA on children's outcomes. No significant moderating effect was found for the two genetic polymorphisms inquired. Children's and mother's outcomes obtained are discussed.