Gene–environment interaction

Children With Disruptive Mood Dysregulation Disorder and Psychopathological Risk in Their Mothers: The Function of Global DNA Methylation

Epigenetic mechanisms, in particular DNA methylation, have been implicated in the etiopathogenesis of psychopathologies in adulthood. The significance of this mechanism in child psychopathologies, however, is much less recognized. Here, we examined whether global DNA methylation alteration was associated with the presence of disruptive mood dysregulation disorder (DMDD) in children. Moreover, in light of the relevance of the interplay between children and parents for the onset and maintaining of psychopathology during development, we measured the association between psychological symptoms, attachment styles, and global DNA methylation levels in healthy and DMDD mother-child dyads (mothers: N = 126, age = 38.3 ± 2.5 years; children: N = 150, age = 8.2 ± 0.9 years, gender ratio [f/m] = 72/78). We did not observe any significant differences in global DNA methylation levels in DMDD children when compared with healthy peers, and children's symptoms did not correlate with variations in this parameter. The mothers showed different levels of psychological symptomatology. Notably, mothers with high psychological symptomatology showed the lowest levels of global DNA methylation. Maternal global DNA methylation levels were associated with maternal hostility, interpersonal sensitivity, psychoticism, and general severity index. Moreover, we found an effect of maternal mental health on the severity of children's symptoms, independently from both maternal and child DNA methylation levels. Despite here DNA methylation does not appear to be involved in the maternal inheritance of vulnerability to depression, this biological link could still arise in later stages of the child's development.

The μ-opioid receptor gene A118G polymorphism is associated with insecure attachment in children with disruptive mood regulation disorder and their mothers

BACKGROUND

The A118G single nucleotide polymorphism (SNP) of the μ-opioid receptor gene, with high expression of the A allele and low expression of the G allele, has been associated with emotional/behavioral dysregulation and depressive disorders and is recognized as a mediator of affiliative behavior. No study has thus far investigated this SNP in school-age children with disruptive mood regulation disorder (DMDD). This study compared a sample of healthy children and their mothers with a sample of children with DMDD and their mothers, evaluating whether insecure attachment and psychopathological symptoms are associated with A allele- or G allele-carrying mothers and children and whether caregiving capacities are associated with A allele- or G allele-carrying mothers.

METHODS

For evaluation of their psychopathological symptoms and attachment styles, mothers filled out the CBCL/6-18, the SCL-90-R, and the ECR. To evaluate the types of relationship children were experiencing with their mothers, children filled out the ECR-revised child version and the PBI. Genotypic analyses were conducted on DNA samples obtained by buccal swabbing from children and mothers.

RESULTS

An insecure attachment style was more frequent in mothers and children carrying the G allele (G/G + A/G genotypes). In the clinical sample, G allele-carrying children scored higher than homozygous A/A ones on the subscales of Withdrawal and Conduct Problems. G-carrying mothers showed higher interpersonal sensitivity, depression, hostility, and paranoid ideation and provided less care than A/A mothers.

CONCLUSIONS

This study offers new insights into the associations between the A118G SNP of the μ-opioid receptor gene and emotional/behavioral functioning, attachment style in children, and psychopathology and caregiving ability in mothers.

Neuroplasticity of selective attention: Research foundations and preliminary evidence for a gene by intervention interaction

This article reviews the trajectory of our research program on selective attention, which has moved from basic research on the neural processes underlying selective attention to translational studies using selective attention as a neurobiological target for evidence-based interventions. We use this background to present a promising preliminary investigation of how genetic and experiential factors interact during development (i.e., gene × intervention interactions). Our findings provide evidence on how exposure to a family-based training can modify the associations between genotype (5-HTTLPR) and the neural mechanisms of selective attention in preschool children from lower socioeconomic status backgrounds.

A translational neuroscience framework for the development of socioemotional functioning in health and psychopathology

The development of socioemotional functioning is a complex process that occurs over a protracted time period and requires coordinating affective, cognitive, and social faculties. At many points in development, the trajectory of socioemotional development can be deleteriously altered due to a combination of environmental insults and individual vulnerabilities. The result can be psychopathology. However, researchers are just beginning to understand the neural and genetic mechanisms involved in the development of healthy and disordered socioemotional functioning. We propose a translational developmental neuroscience framework to understand the transactional process that results in socioemotional functioning in both healthy and disordered populations. We then apply this framework to healthy socioemotional development, pediatric anxiety, pediatric depression, and autism spectrum disorder, selectively reviewing current literature in light of the framework. Finally, we examine ways that the framework can help to frame future directions of research on socioemotional development and translational implications for intervention.

What makes narcissists bloom? A framework for research on the etiology and development of narcissism

Narcissism is a dynamic form of personality characterized by a pervasive sense of grandiosity and self-importance, and by a need to obtain continuous self-validation from others. Very little is known about its etiology and development. What factors (e.g., temperament, parenting experiences) and processes (e.g., transactions between these factors over time) cause some children to become more narcissistic than others? When does narcissism first emerge, and how does narcissism develop over time? This article describes a framework for research on the etiology and development of narcissism, and recommends ten research priorities. This research should yield fundamental knowledge and should inform intervention efforts to minimize the negative impact narcissistic individuals have on themselves and on others.

The Concept of Development in Developmental Psychopathology

So important is the perspective of development for understanding psychopathology that it spawned a new discipline-"developmental psychopathology"-which has seen remarkable advances since its introduction,, but has yet to completely fulfill its promise. To do this requires maintaining a thoroughgoing developmental perspective. When we take development seriously, there are implications for how we understand psychopathology, describe and conceptualize the origins and course of disorder, and interpret research findings. From this perspective, disorders are complex products of development; for example, we can view neurophysiological associates of disorder not as causes but as markers, the development of which we need to understand. Research on developmental psychopathology requires an examination of the history of problem behavior from early in life, and it unites multiple features of adaptation and maladaptation (contextual, experiential, physiological, and genetic).

Generalized anxiety disorder: connections with self-reported attachment

Even though generalized anxiety disorder (GAD) is one of the most common of the anxiety disorders, relatively little is known about its precursors. Bowlby's attachment theory provides a framework within which these precursors can be considered. According to Bowlby, adult anxiety may be rooted in childhood experiences that leave a child uncertain of the availability of a protective figure in times of trouble.Furthermore, adult "current state of mind with respect to attachment" is thought to relate to adult anxiety. Both attachment-related components were assessed with 8 subscales of the Perceptions of Adult Attachment Questionnaire(PAAQ). Clinically severe GAD clients who were about to begin therapy reported experiencing less maternal love in childhood, greater maternal rejection/neglect, and more maternal role-reversal/enmeshment than did control participants.In keeping with a cumulative risk model, risk for GAD increased as indices of poor childhood attachment experience increased. GAD clients, in contrast to controls,also reported greater current vulnerability in relation to their mothers as well as more difficulty accessing childhood memories. Logistic regression analyses revealed that elevations on PAAQ subscales could significantly predict GAD vs.non-GAD status. Results and the implications for advancing the theory and treatment of GAD are discussed.

Amygdala function and 5-HTT gene variants in adolescent anxiety and major depressive disorder

BACKGROUND

Associations between a functional polymorphism in the serotonin transporter gene and amygdala activation have been found in healthy, depressed, and anxious adults. This study explored these gene-brain associations in adolescents by examining predictive effects of serotonin transporter gene variants (S and L(G) allele carriers vs. L(A) allele homozygotes) and their interaction with diagnosis (healthy vs. patients) on amygdala responses to emotional faces.

METHODS

Functional magnetic resonance data were collected from 33 healthy adolescents (mean age: 13.71, 55% female) and 31 medication-free adolescents with current anxiety or depressive disorders (or both; mean age: 13.58, 56% female) while viewing fearful, angry, happy, and neutral facial expressions under varying attention states.

RESULTS

A significant three-way genotype-by-diagnosis-by-face-emotion interaction characterized right amygdala activity while subjects monitored internal fear levels. This interaction was decomposed to map differential gene-brain associations in healthy and affected adolescents. First, consistent with healthy adult data, healthy adolescents with at least one copy of the S or L(G) allele showed stronger amygdala responses to fearful faces than healthy adolescents without these alleles. Second, patients with two copies of the L(A) allele exhibited greater amygdala responses to fearful faces relative to patients with S or L(G) alleles. Third, although weaker, genotype differences on amygdala responses in patients extended to happy faces. All effects were restricted to the fear-monitoring attention state.

CONCLUSIONS

S/L(G) alleles in healthy adolescents, as in healthy adults, predict enhanced amygdala activation to fearful faces. Contrary findings of increased activation in patients with L(A)L(A) relative to the S or L(G) alleles require further exploration.

Ten good reasons to consider biological processes in prevention and intervention research

Most contemporary accounts of psychopathology acknowledge the importance of both biological and environmental influences on behavior. In developmental psychopathology, multiple etiological mechanisms for psychiatric disturbance are well recognized, including those operating at genetic, neurobiological, and environmental levels of analysis. However, neuroscientific principles are rarely considered in current approaches to prevention or intervention. In this article, we explain why a deeper understanding of the genetic and neural substrates of behavior is essential for the next generation of preventive interventions, and we outline 10 specific reasons why considering biological processes can improve treatment efficacy. Among these, we discuss (a) the role of biomarkers and endophenotypes in identifying those most in need of prevention; (b) implications for treatment of genetic and neural mechanisms of homotypic comorbidity, heterotypic comorbidity, and heterotypic continuity; (c) ways in which biological vulnerabilities moderate the effects of environmental experience; (d) situations in which Biology x Environment interactions account for more variance in key outcomes than main effects; and (e) sensitivity of neural systems, via epigenesis, programming, and neural plasticity, to environmental moderation across the life span. For each of the 10 reasons outlined we present an example from current literature and discuss critical implications for prevention.