Serotonergic function, two-mode models of self-regulation, and vulnerability to depression: what depression has in common with impulsive aggression

Intergenerational transmission of self-regulation: A multidisciplinary review and integrative conceptual framework

This review examines mechanisms contributing to the intergenerational transmission of self-regulation. To provide an integrated account of how self-regulation is transmitted across generations, we draw from over 75 years of accumulated evidence, spanning case studies to experimental approaches, in literatures covering developmental, social, and clinical psychology, and criminology, physiology, genetics, and human and animal neuroscience (among others). First, we present a taxonomy of what self-regulation is and then examine how it develops--overviews that guide the main foci of the review. Next, studies supporting an association between parent and child self-regulation are reviewed. Subsequently, literature that considers potential social mechanisms of transmission, specifically parenting behavior, interparental (i.e., marital) relationship behaviors, and broader rearing influences (e.g., household chaos) is considered. Finally, evidence that prenatal programming may be the starting point of the intergenerational transmission of self-regulation is covered, along with key findings from the behavioral and molecular genetics literatures. To integrate these literatures, we introduce the self-regulation intergenerational transmission model, a framework that brings together prenatal, social/contextual, and neurobiological mechanisms (spanning endocrine, neural, and genetic levels, including gene-environment interplay and epigenetic processes) to explain the intergenerational transmission of self-regulation. This model also incorporates potential transactional processes between generations (e.g., children's self-regulation and parent-child interaction dynamics that may affect parents' self-regulation) that further influence intergenerational processes. In pointing the way forward, we note key future directions and ways to address limitations in existing work throughout the review and in closing. We also conclude by noting several implications for intervention work.

A genetic analysis of the validity of the Hypomanic Personality Scale

OBJECTIVES

Studies of mania risk have increasingly relied on measures of subsyndromal tendencies to experience manic symptoms. The measures of mania risk employed in those studies have been shown to predict manic onset, to show familial associations, and to demonstrate expected correlations with psychosocial variables related to bipolar disorder. However, little work has been conducted to validate such measures against biologically relevant indices, or to consider whether early adversity, which has been shown to be highly elevated among those with bipolar disorder, is related to higher scores on mania risk measures. This study tested whether a well-used, self-report measure of vulnerability to mania is associated with several candidate genes that have previously been linked with bipolar disorder or with early adversity. Interactions of genes with early adversity in the prediction of mania vulnerability were also tested.

METHODS

Undergraduate students from the University of Miami (Coral Gables, FL, USA) (N = 305) completed the Hypomanic Personality Scale and the Risky Families Scale, and provided blood for genotyping.

RESULTS

Findings indicated that the Hypomanic Personality Scale was related to a number of dopamine-relevant polymorphisms and with early adversity. A polymorphism of ANKK1 appeared to specifically increase mania risk in the context of early adversity.

CONCLUSIONS

These results provide additional support for the validity of the Hypomanic Personality Scale.

"Bad genes" & criminal responsibility

The genetics of the accused is trying to break into the courts. To date several candidate genes have been put forward and their links to antisocial behavior have been examined and documented with some consistency. In this paper, we focus on the so called "warrior gene", or the low-activity allele of the MAOA gene, which has been most consistently related to human behavior and specifically to violence and antisocial behavior. In preparing this paper we had two objectives. First, to summarize and analyze the current scientific evidence, in order to gain an in depth understanding of the state of the issue and determine whether a dominant line of generally accepted scientific knowledge in this field can be asserted. Second, to derive conclusions and put forward recommendations related to the use of genetic information, specifically the presence of the low-activity genotype of the MAOA gene, in modulation of criminal responsibility in European and US courts.

Self-Monitoring and the Metatraits

Prior attempts at locating self-monitoring within general taxonomies of personality traits have largely proved unsuccessful. However, past research has typically neglected (a) the bidimensionality of the Self-Monitoring Scale and (b) the hierarchical nature of personality. The objective of this study was to test hypotheses that the two self-monitoring factors are located at the level of the metatraits. Using data from two large multi-informant samples, one community (Sample 1: N = 552, Mage  = 51.26, 61% female; NPeers  = 1,551, Mage  = 48.61, 37% female) and one online (Sample 2: N = 3,726, Mage  = 24.89, 59% female; NPeers  = 17,868, Mage  = 26.23, 64% female), confirmatory factor analysis was used to test the hypotheses. Results confirmed hypotheses that acquisitive self-monitoring would have a strong positive relation to metatrait Plasticity, whereas protective self-monitoring would have a moderate negative relation to metatrait Stability. In both samples, constraining the correlation between acquisitive self-monitoring and Plasticity to unity did not alter model fit indices, indicating that the two putatively distinct constructs are identical. Findings have wide-ranging implications, including integration of the construct of self-monitoring into the mainstream of personality research, as the latter moves toward the development of broad explanatory theories.

A two-factor model of relapse/recurrence vulnerability in unipolar depression

The substantial health burden associated with major depressive disorder (MDD) is a product of both its high prevalence and the significant risk of relapse, recurrence, and chronicity. Establishing recurrence vulnerability factors (VFs) could improve the long-term management of MDD by identifying the need for further intervention in seemingly recovered patients. We present a model of sensitization in depression vulnerability, with an emphasis on the integration of behavioral and neural systems accounts. Evidence suggests that VFs fall into 2 categories: dysphoric attention and dysphoric elaboration. Dysphoric attention is driven by fixation on negative life events, and is characterized behaviorally by reduced executive control, and neurally by elevated activity in the brain's salience network. Dysphoric elaboration is driven by rumination that promotes overgeneral self- and contextual appraisals, and is characterized behaviorally by dysfunctional attitudes, and neurally by elevated connectivity within normally distinct prefrontal brain networks. Although few prospective VF studies exist from which to catalogue a definitive neurobehavioral account, extant data support the value of the proposed 2-factor model. Measuring the continued presence of these 2 VFs during recovery may more accurately identify remitted patients who would benefit from targeted prophylactic intervention.

Associations between catecholaminergic, GABAergic, and serotonergic genes and self-reported attentional function in oncology patients and their family caregivers

PURPOSE OF THE RESEARCH

Evaluate for associations between variations in genes involved in catecholaminergic, gamma-aminobutyric acid (GABA)-ergic, and serotonergic mechanisms of neurotransmission and attentional function latent classes.

PATIENTS AND METHODS

This descriptive, longitudinal study was conducted at two radiation therapy departments. The sample included three latent classes of individuals with distinct trajectories of self-reported attentional function during radiation therapy, who were previously identified using growth mixture modeling among 167 oncology patients and 85 of their family caregivers. Multivariable models were used to evaluate for genotypic associations of neurotransmission genes with attentional function latent class membership, after controlling for covariates.

RESULTS

Variations in catecholaminergic (i.e., ADRA1D rs4815675, SLC6A3 rs37022), GABAergic (i.e., SLC6A1 rs2697138), and serotonergic (i.e., HTR2A rs2296972, rs9534496) neurotransmission genes were significant predictors of latent class membership in multivariable models.

CONCLUSIONS

Findings suggest that variations in genes that encode for three distinct but related neurotransmission systems are involved in alterations in attentional function. Knowledge of both phenotypic and genetic markers associated with alterations in attentional function can be used by clinicians to identify patients and family caregivers who are at higher risk for this symptom. Increased understanding of the genetic markers associated with alterations in attentional function may provide insights into the underlying mechanisms for this significant clinical problem.

En Route to Depression: Self-Esteem Discrepancies and Habitual Rumination

Dual-process models of cognitive vulnerability to depression suggest that some individuals possess discrepant implicit and explicit self-views, such as high explicit and low implicit self-esteem (fragile self-esteem) or low explicit and high implicit self-esteem (damaged self-esteem). This study investigated whether individuals with discrepant self-esteem may employ depressive rumination in an effort to reduce discrepancy-related dissonance, and whether the relationship between self-esteem discrepancy and future depressive symptoms varies as a function of rumination tendencies. Hierarchical regressions examined whether self-esteem discrepancy was associated with rumination in an Australian undergraduate sample at Time 1 (N = 306; M(age) = 29.9), and whether rumination tendencies moderated the relationship between self-esteem discrepancy and depressive symptoms assessed 3 months later (n = 160). Damaged self-esteem was associated with rumination at Time 1. As hypothesized, rumination moderated the relationship between self-esteem discrepancy and depressive symptoms at Time 2, where fragile self-esteem and high rumination tendencies at Time 1 predicted the highest levels of subsequent dysphoria. Results are consistent with dual-process propositions that (a) explicit self-regulation strategies may be triggered when explicit and implicit self-beliefs are incongruent, and (b) rumination may increase the likelihood of depression by expending cognitive resources and/or amplifying negative implicit biases.

Association between serotonin cumulative genetic score and the Behavioral Approach System (BAS): Moderation by early life environment

The present study investigates if genetic variation in the serotonergic system interacts with early adversity to predict changes in the Behavioral Approach System (BAS), a system that taps into reward processing. In a sample of community adults (N= 236) the influence of single serotonergic candidate polymorphisms on BAS was analyzed, we also examined the aggregate contribution of these genetic variants by creating a Cumulative Genetic Score (CGS). A CGS quantifies an individual's cumulative risk by aggregating the number of risk alleles across the candidate polymorphisms. After individual gene analysis, three candidate genes rs7305115 (TPH2), rs6311 (HTR2A), and rs6295 (HTR1A) were combined into the CGS. There were no significant interactions between individual candidate polymorphisms and childhood adversity, but the CGS interacted with childhood adversity to explain a significant amount of variance (11.6%) in the BAS. Findings suggest that genetic variations in the serotonergic system in combination with childhood adversity contribute to individual differences in reward sensitivity.

Serotonin transporter polymorphisms predict response inhibition in healthy volunteers

Serotoninergic transmission is reliably implicated in inhibitory control processes. The aim of this study was to test the hypothesis if serotonin transporter polymorphisms mediate inhibitory control in healthy people. 141 healthy subjects, carefully screened for previous and current psychopathology, were genotyped for the 5-HTTLPR and rs25531 polymorphisms. Inhibitory control was ascertained with the Stop Signal Task (SST) from the Cambridge Neuropsychological Test Automated Battery (CANTAB). The triallelic gene model, reclassified and presented in a biallelic functional model, revealed a dose-dependent gene effect on SST performance with Individuals carrying the low expressive allele had inferior inhibitory control compared to high expressive carriers. This directly implicates serotonin transporter polymorphisms (5-HTTLPR plus rs25531) in response inhibition in healthy subjects.

A novel model of early experiences involving neonatal learning of a T-maze using maternal contact as a reward or its denial as an event of mild emotional adversity

We developed a novel animal model of early life experiences in which rat pups are trained during postnatal days (PND) 10-13 in a T-maze with maternal contact as a reward (RER group) or its denial (DER group) as a mildly aversive event. Both groups of animals learn the T-maze, albeit the RER do so more efficiently. Training results in activation of the basal ganglia in the RER and of the hippocampus and prefrontal cortex in the DER. Moreover, on PND10 DER training leads to increased corticosterone levels and activation of the amygdala. In adulthood, male DER animals show better mnemonic abilities in the Morris water maze while the RER exhibit enhanced fear memory. Furthermore, DER animals have a hypofunctioning serotonergic system and express depressive-like behavior and increased aggression. However, they have increased hippocampal glucocorticoid receptors, indicative of efficient hypothalamic-pituitary-adrenal axis function, and an adaptive pattern of stress-induced corticosterone response. The DER experience with its relatively negative emotional valence results in a complex behavioral phenotype, which cannot be considered simply as adaptive or maladaptive.

Maternal unresponsiveness and child disruptive problems: the interplay of uninhibited temperament and dopamine transporter genes

This study examined how and why dopamine transporter (DAT1) susceptibility alleles moderate the relation between maternal unresponsiveness and young children's behavior problems in a disadvantaged, predominantly minority sample of 201 two-year-old children and their mothers. Using a multimethod, multisource design, the findings indicated that a genetic composite of DAT1 susceptibility alleles (rs27072, rs40184) potentiated associations between maternal unresponsive caregiving and increases in children's behavior problems 2 years later. Moderator-mediated-moderation analyses further revealed that the DAT1 diathesis was more proximally mediated by the potentiating effects of children's uninhibited temperament in the pathway between maternal unresponsiveness and disruptive behavior problems. Results are interpreted in the context of supporting and advancing the biosocial developmental model (Beauchaine & Gatzke-Kopp, 2012).

Proposed mechanisms for cancer- and treatment-related cognitive changes

OBJECTIVES

To review the proposed mechanisms of cognitive changes associated with non-central nervous system cancers and cancer treatment.

DATA SOURCES

Review and synthesis of databased publications and review articles.

CONCLUSION

Proposed mechanisms include cytokine upregulation, hormonal changes, neurotransmitter dysregulation, attentional fatigue, genetic predisposition, and comorbid symptoms.

IMPLICATIONS FOR NURSING PRACTICE

Oncology nurses need to understand the multiple mechanisms that may contribute to the development of cancer- and treatment-related cognitive changes so that they can identify patients at high risk and help patients understand why these changes occur.

Candidate genes for aggression and antisocial behavior: a meta-analysis of association studies of the 5HTTLPR and MAOA-uVNTR

Variation in central serotonin levels due to genetic mutations or experimental modifications has been associated with the manifestation of aggression in humans and animals. Many studies have examined whether common variants in serotonergic genes are implicated in aggressive or antisocial behaviors (ASB) in human samples. The two most commonly studied polymorphisms have been the serotonin transporter linked polymorphic region of the serotonin transporter gene (5HTTLPR) and the 30 base pair variable number of tandem repeats of the monoamine oxidase A gene (MAOA-uVNTR). Despite the aforementioned theoretical justification for these polymorphisms, findings across studies have been mixed and are thus difficult to interpret. A meta-analysis of associations of the 5HTTLPR and MAOA-uVNTR with ASB was conducted to determine: (1) the overall magnitude of effects for each polymorphism, (2) the extent of heterogeneity in effect sizes across studies and the likelihood of publication bias, and (3) whether sample-level or study-level characteristics could explain observed heterogeneity across studies. Both the 5HTTLPR and the MAOA-uVNTR were significantly associated with ASB across studies. There was also significant and substantial heterogeneity in the effect sizes for both markers, but this heterogeneity was not explained by any sample-level or study-level characteristics examined. We did not find any evidence for publication bias across studies for the MAOA-uVNTR, but there was evidence for an oversampling of statistically significant effect sizes for the 5HTTLPR. These findings provide support for the modest role of common serotonergic variants in ASB. Implications regarding the role of serotonin in antisocial behavior and the conceptualization of antisocial and aggressive phenotypes are discussed.

Association between parental emotional symptoms and child antisocial behaviour

Parental anxiety and depression are associated with antisocial behaviour of children. Several mechanisms may mediate this association. The aim of this study was to test whether parenting is a mediator of the association of parental anxiety and depression with the antisocial social behaviour of preschool children. The analysis was based on cross-sectional data and 106 German families of children with elevated externalizing behaviour problems were considered. Mothers and fathers were analysed separately. Depression and anxiety in parents were both associated with children’s antisocial behaviour and this association was mediated by parenting. Further, our results indicated that the association between maternal depression and child behaviour is maintained after controlling for maternal anxiety, and that parenting of mothers is more strongly associated with child behaviour than parenting of fathers.

The effect of neighborhood disadvantage, social ties, and genetic variation on the antisocial behavior of African American women: a multilevel analysis

Social disorganization theory posits that individuals who live in disadvantaged neighborhoods are more likely to engage in antisocial behavior than are those who live in advantaged neighborhoods and that neighborhood disadvantage asserts this effect through its disruptive impact on social ties. Past research on this framework has been limited in two respects. First, most studies have concentrated on adolescent males. In contrast, the present study focused on a sample of adult African American females. Second, past research has largely ignored individual-level factors that might explain why people who grow up in disadvantaged neighborhoods often do not engage in antisocial behavior. We investigated the extent to which genetic variation contributes to heterogeneity of response to neighborhood conditions. We found that the impact of neighborhood disadvantage on antisocial behavior was mediated by neighborhood social ties. Further, the analysis indicated that the effects of neighborhood disadvantage and social ties on antisocial behavior were moderated by genetic polymorphisms. Examination of these moderating effects provided support for the differential susceptibility model of Gene × Environment. The effect of Gene × Neighborhood Disadvantage on antisocial behavior was mediated by the effect of Gene × Neighborhood Social Ties, providing support for an expanded view of social disorganization theory.

Gene Effects and G × E Interactions in the Differential Prediction of Three Aspects of Impulsiveness

Several polymorphisms relevant to dopamine and serotonin have been identified as potential contributors to individual differences in impulsivity versus self-control. Because impulsivity is a multifaceted construct, a need remains to examine more closely how various genes relate to different aspects of impulsivity. We examined four dopamine-related polymorphisms and the serotonin transporter as predictors of three aspects of impulsivity, two bearing on impulsive reactions to emotions and one on difficulty in completing intended actions. Early adversity was also examined as a potentiator of genetic effects. Undergraduates completed measures of impulsivity and early adversity and were genotyped. COMT, BDNF, DRD4, and 5HTTLPR (the latter two in interaction with early adversity) made independent contributions to prediction of Pervasive Influence of Feelings. BDNF made a contribution to Lack of Follow-Through. ANKK1 and 5HTTLPR (both in interaction with early adversity) made independent contributions to Feelings Trigger Action. Thus, five polymorphisms contributed to predicting impulsivity, but different polymorphisms related to different aspects.

Ventral striatal dopamine synthesis capacity is associated with individual differences in behavioral disinhibition

Pathological gambling, alongside addictive and antisocial disorders, forms part of a broad psychopathological spectrum of externalizing disorders, which share an underlying genetic vulnerability. The shared externalizing propensity is a highly heritable, continuously varying trait. Disinhibitory personality traits such as impulsivity and novelty seeking (NS) function as indicators of this broad shared externalizing tendency, which may reflect, at the neurobiological level, variation in the reactivity of dopaminergic (DAergic) brain reward systems centered on the ventral striatum (VS). Here, we examined whether individual differences in ventral striatal dopamine (DA) synthesis capacity were associated with individual variation in disinhibitory personality traits. Twelve healthy male volunteers underwent 6-[¹⁸F]Fluoro-L-DOPA (FDOPA) positron emission tomography (PET) scanning to measure striatal DA synthesis capacity, and completed a measure of disinhibited personality (NS). We found that levels of ventral, but not dorsal, striatal DA synthesis capacity were significantly correlated with inter-individual variation in disinhibitory personality traits, particularly a propensity for financial extravagance and irresponsibility. Our results are consistent with preclinical models of behavioral disinhibition and addiction proneness, and provide novel insights into the neurobiology of personality based vulnerability to pathological gambling and other externalizing disorders.

A sociogenomic perspective on neuroscience in organizational behavior

We critically examine the current biological models of individual organizational behavior, with particular emphasis on the roles of genetics and the brain. We demonstrate how approaches to biology in the organizational sciences assume that biological systems are simultaneously causal and essentially static; that genotypes exert constant effects. In contrast, we present a sociogenomic approach to organizational research, which could provide a meta-theoretical framework for understanding organizational behavior. Sociogenomics is an interactionist approach that derives power from its ability to explain how genes and environment operate. The key insight is that both genes and the environment operate by modifying gene expression. This leads to a conception of genetic and environmental effects that is fundamentally dynamic, rather than the static view of classical biometric approaches. We review biometric research within organizational behavior, and contrast these interpretations with a sociogenomic view. We provide a review of gene expression mechanisms that help explain the dynamism observed in individual organizational behavior, particularly factors associated with gene expression in the brain. Finally, we discuss the ethics of genomic and neuroscientific findings for practicing managers and discuss whether it is possible to practically apply these findings in management.

How and why does the 5-HTTLPR gene moderate associations between maternal unresponsiveness and children's disruptive problems?

This study tested the 5-HTTLPR gene as a moderator in the relation between maternal unresponsiveness and child externalizing symptoms in a disadvantaged, predominantly Black sample of two hundred and one 2-year-old children and their mothers. Using a multimethod, prospective design, structural equation model analyses indicated that maternal unresponsiveness significantly predicted increases in externalizing symptoms 2 years later only for children possessing the LL genotype. Moderation was expressed in a "for better" or "for worse" form hypothesized in differential susceptibility theory. In examining why the risk posed by maternal unresponsiveness differed across the 5-HTTLPR polymorphism, mediated moderation analyses showed that children's angry reactivity to maternal negativity partly accounted for the greater susceptibility of homozygous L carriers to variations in maternal unresponsiveness.

Peril and pleasure: an rdoc-inspired examination of threat responses and reward processing in anxiety and depression

As a step toward addressing limitations in the current psychiatric diagnostic system, the National Institute of Mental Health recently developed the Research Domain Criteria (RDoC) to stimulate integrative research-spanning self-report, behavior, neural circuitry, and molecular/genetic mechanisms-on core psychological processes implicated in mental illness. Here, we use the RDoC conceptualization to review research on threat responses, reward processing, and their interaction. The first section of the manuscript highlights the pivotal role of exaggerated threat responses-mediated by circuits connecting the frontal cortex, amygdala, and midbrain-in anxiety, and reviews data indicating that genotypic variation in the serotonin system is associated with hyperactivity in this circuitry, which elevates the risk for anxiety and mood disorders. In the second section, we describe mounting evidence linking anhedonic behavior to deficits in psychological functions that rely heavily on dopamine signaling, especially cost/benefit decision making and reward learning. The third section covers recent studies that document negative effects of acute threats and chronic stress on reward responses in humans. The mechanisms underlying such effects are unclear, but the fourth section reviews new optogenetic data in rodents indicating that GABAergic inhibition of midbrain dopamine neurons, driven by activation of the habenula, may play a fundamental role in stress-induced anhedonia. In addition to its basic scientific value, a better understanding of interactions between the neural systems that mediate threat and reward responses may offer relief from the burdensome condition of anxious depression.

Dorsal prefrontal cortical serotonin 2A receptor binding indices are differentially related to individual scores on harm avoidance

Although the serotonergic system has been implicated in healthy as well as in pathological emotional states, knowledge about its involvement in personality is limited. Earlier research on this topic suggests that post-synaptic 5-HT2A receptors could be involved in particular in frontal cortical areas. In drug-naïve healthy individuals, we examined the relationship between these 5-HT2A receptors and the temperament dimension harm avoidance (HA) using 123I-5-I-R91150 single photon emission computed tomography (SPECT). HA is a personality feature closely related to stress, anxiety and depression proneness, and it is thought to be mediated by the serotonergic system. We focused on the prefrontal cortices as these regions are frequently implicated in cognitive processes related to a variety of affective disorders. We found a positive relationship between dorsal prefrontal cortical (DPFC) 5-HT2A receptor binding indices (BI) and individual HA scores. Further, our results suggest that those individuals with a tendency to worry or to ruminate are particularly prone to display significantly higher 5-HT2A receptor BI in the left DPFC. Although we only examined psychologically healthy individuals, this relationship suggests a possible vulnerability for affective disorders.

Combining neural and behavioral indicators in the assessment of internalizing psychopathology in children and adolescents

Anxiety and mood disorders are among the most prevalent mental health problems affecting our youth. We propose that assessment and treatment efforts in this area can benefit from a focus on developmentally sensitive neurobehavioral trait constructs, that is, individual difference constructs with direct referents in both neurobiology and behavior across the lifespan. This approach dovetails with the National Institute of Mental Health's Research Domain Criteria initiative, which aims to improve classification and treatment of psychopathology by delineating dimensions of functioning that transcend measurement domains and traditional diagnostic categories. We highlight two neurobehavioral dimensions with clear relevance for understanding internalizing problems at differing ages: (a) defensive reactivity and (b) cognitive control. Individual differences in defensive reactivity are posited to reflect variations in sensitivity of the brain's negative valence systems, whereas differences in cognitive control are theorized to reflect variations in neural systems dedicated to regulating behavior and affect. Focusing on these target constructs, we illustrate a psychoneurometric approach to assessment of internalizing psychopathology entailing use of neural, self-report, and behavioral indicators. We address the feasibility of the psychoneurometric approach for clinical application and present results from a pilot study demonstrating expected associations for neural, parent-report, and behavioral measures of defensive reactivity and cognitive control with internalizing symptoms in preschoolers. Together, our conceptual and empirical analyses highlight the promise of multimethod, dimensional assessment of internalizing psychopathology in the lab and in the clinic.

Is serotonin transporter genotype associated with epigenetic susceptibility or vulnerability? Examination of the impact of socioeconomic status risk on African American youth

We hypothesized that presence of the short allele in the promoter region of the serotonin transporter would moderate the effect of early cumulative socioeconomic status (SES) risk on epigenetic change among African American youth. Contrasting hypotheses regarding the shape of the interaction effect were generated using vulnerability and susceptibility frameworks and applied to data from a sample of 388 African American youth. Early cumulative SES risk assessed at 11-13 years based on parent report interacted with presence of the short allele to predict differential methylation assessed at age 19. Across multiple tests, a differential susceptibility perspective rather than a diathesis-stress framework best fit the data for genes associated with depression, consistently demonstrating greater epigenetic response to early cumulative SES risk among short allele carriers. A pattern consistent with greater impact among short allele carriers also was observed using all cytosine nucleotide-phosphate-guanine nucleotide sites across the genome that were differentially affected by early cumulative SES risk. We conclude that the short allele is associated with increased responsiveness to early cumulative SES risk among African American youth, leading to epigenetic divergence for depression-related genes in response to exposure to heightened SES risk among short allele carriers in a "for better" or "for worse" pattern.

Paradoxical effects of short-term antidepressant treatment in fMRI emotional processing models in volunteers with high neuroticism

BACKGROUND

Short-term antidepressant administration has been reported to decrease amygdala response to threat in healthy volunteers and depressed patients. Neuroticism (N) is a risk factor for depression but has also been associated with slow or incomplete remission with antidepressant drug treatment. Our aim was to investigate early selective serotonin reuptake inhibitor (SSRI) administration neural effects on implicit processing of fearful facial expressions in volunteers with high levels of N.

METHOD

Highly neurotic subjects received 20 mg/day citalopram versus placebo for 7 days in a double-blind, between-groups design. On the last day haemoperfusion and functional magnetic resonance imaging (fMRI) data during a gender discrimination task with fearful and happy faces were acquired. A control group of non-neurotic volunteers was also tested.

RESULTS

High-N volunteers had reduced responses to threatening facial expressions across key neural circuits compared to low-N volunteers. SSRI treatment was found to elevate resting perfusion in the right amygdala, increase bilateral amygdalae activation to positive and negative facial expressions and increase activation to fearful versus happy facial expressions in occipital, parietal, temporal and prefrontal cortical areas.

CONCLUSIONS

These results suggest that 7 days of SSRI administration can increase neural markers of fear reactivity in subjects at the high end of the N dimension and may be related to early increases in anxiety and agitation seen early in treatment. Such processes may be involved in the later therapeutic effects through decreased avoidance and increased learning about social 'threat' cues.

Serotonin Transporter Genotype Linked to Adolescent Substance Use Treatment Outcome through Externalizing Behavior

Meta-analyses suggest that the serotonin transporter linked polymorphic region (5-HTTLPR) short (S) allele, relative to the long (L) allele, is associated with risk for alcohol dependence, particularly among individuals with early onset antisocial alcoholism. Youth in substance use treatment tend to show antisocial or externalizing behaviors, such as conduct problems, which predict worse treatment outcome. This study examined a pathway in which 5-HTTLPR genotype is associated with externalizing behavior, and the intermediate phenotype of externalizing behavior serves as a link between 5-HTTLPR genotype and substance use treatment outcome in youth. Adolescents (n = 142) who were recruited from addictions treatment were genotyped for 5-HTTLPR polymorphisms (S and LG carriers vs. LALA), assessed for externalizing and internalizing behaviors shortly after starting treatment, and followed over 6-months. 5-HTTLPR genotype was not associated with internalizing behaviors, and was not directly associated with 6-month substance use outcomes. However, 5-HTTLPR genotype was associated with externalizing behaviors (S and LG > LALA), and externalizing behaviors predicted alcohol and marijuana problem severity at 6-month follow-up. Results indicated an indirect (p < 0.05) and non-specific (i.e., both alcohol and marijuana severity) effect of 5-HTTLPR genotype on youth substance use treatment outcomes, with externalizing behaviors as an important linking factor. Adolescents in substance use treatment with low expressing (S and LG) 5-HTTLPR alleles and externalizing behavior might benefit from intervention that addresses serotonergic functioning, externalizing behaviors, and substance use to improve outcomes.

The "S" Allele of the Serotonin Transporter Is Not Associated with Major Depression or Alcohol Use Disorders in a Veteran Sample

The results of some studies suggest that the serotonin transporter-linked polymorphic region (5-HTTLPR) short (S) allele, relative to the long (L) allele, is associated with risk for Major Depressive Disorder (MDD) and for Alcohol Use Disorder (AUD), and thus serves as biomarker for those disorders, while results from other studies do not support that conclusion. Persons with an S allele demonstrate a 2- to 2.5 fold decrease in serotonin transcription rate compared to the L-allele, which may increase their risk for MDD. Differences in study populations may help explain the differences in findings between those meta-analyses. To date, there have been no published reports which have addressed the possible association between the S allele and MDD among military veterans. This manuscript describes a first study to assess the possible association of the S allele with MDD or with AUD among a study population of veterans in treatment for a substance use disorder. We hypothesized that the S allele would be associated with MDD in our study sample. Subjects signing informed consent were 101 Veterans recruited from VA behavioral health and substance use treatment clinics in the VA Pittsburgh Healthcare System, and 91 of those subjects were genotyped for 5-HTTLPR polymorphisms. The study sample from whom genetic material was collected included 82 males and 9 females, of whom 53 were white, 38 were black, and one was "other". Fifty-four members of the study sample (59%) met DSM-IV criteria for an MDD on the SCID. Forty-five of the subjects demonstrated one or two S alleles, while 46 did not do so. The presence of the S allele of the serotonin transporter was not found to be significantly associated with the diagnosis of major depressive disorder or with alcohol use disorders in our sample. Those findings, in combination with other recent negative findings from other researchers involving non-veterans, raise questions regarding the clinical utility of utilizing genetics tests involving the assessment of the alleles of the serotonin transporter as a possible biomarker for MDD or for AUD.

The "S" Allele of the Serotonin Transporter Is Not Associated with Major Depression in a Sample OF Veterans

The results of some studies suggest that the serotonin transporter-linked polymorphic region (5-HTTLPR) short (S) allele, relative to the long (L) allele, is associated with risk for Major Depressive Disorder (MDD), and thus serves as a biomarker for MDD, while results from other studies do not support that conclusion. Persons with an S allele demonstrate a 2- to 2.5 fold decrease in serotonin transcription rate compared to the L-allele, which may increase their risk for MDD. Differences in study populations may help explain the differences in findings between those meta-analyses. To date, there have been no published reports which have addressed the possible association between the S allele and MDD among military veterans. This manuscript describes a first study to assess the possible association of the S allele with MDD among a study population of veterans in treatment for a substance use disorder. We hypothesized that the S allele would be associated with MDD in our study sample. Subjects signing informed consent were 101 Veterans recruited from VA behavioral health and substance use treatment clinics in the VA Pittsburgh Healthcare System, and 91 of those subjects were genotyped for 5-HTTLPR polymorphisms. The study sample from whom genetic material was collected included 82 males and 9 females, of whom 53 were white, 38 were black, and one was "other". Fifty-four members of the study sample (59%) met DSM-IV criteria for an MDD on the SCID. Forty-five of the subjects demonstrated one or two S alleles, while 46 did not do so. The presence of the S allele of the serotonin transporter was not found to be significantly associated with the diagnosis of major depressive disorder in our sample (Chi-square=0.1.63, df=1, p=0.199). That finding, in combination with other recent negative findings from other researchers involving non-veterans, raises questions regarding the clinical utility of utilizing genetics tests involving the assessment of the alleles of the serotonin transporter as a possible biomarker for MDD.

Relationship between anhedonia and impulsivity in schizophrenia, major depression and schizoaffective disorder

BACKGROUND

Anhedonia and impulsivity are prominent symptoms of many psychiatric disorders and may indicate worse prognosis, notably in schizophrenia and major depression. Despite the convergence of negative outcomes from both dimensions, the relationship between anhedonia and impulsivity in psychiatric disorders has been seldom directly assessed. The objective of the present study is to examine the correlations between anhedonia and impulsivity in three diagnostic groups: major depression, schizophrenia and schizoaffective disorder.

SAMPLING AND METHODS

121 outpatients (Mansoura University Hospital, Egypt) with major depressive disorder (N=29), schizophrenia (N=59), and schizoaffective disorder (N=33), were assessed and responded to the Beck Depression Inventory, Barrat's Impulsivity Scale-11, and Chapman's Social and Physical Anhedonia Scales.

RESULTS

Physical and social anhedonia scores were negatively correlated to impulsivity scores in major depression patients. Conversely, higher scores in physical and social anhedonia predicted higher impulsivity scores in schizophrenia. No correlations between impulsivity and anhedonia were evidenced among schizoaffectives.

CONCLUSION

The relationship between self-reported physical and social anhedonia and impulsivity is diagnosis-specific.

Serotonin transporter genotype (5-HTTLPR) and electrocortical responses indicating the sensitivity to negative emotional cues

Growing literature indicates that emotional reactivity and regulation are strongly linked to genetic modulation of serotonergic neurotransmission. However, until now, most studies have focused on the relationship between genotypic markers, in particular the serotonin transporter-linked polymorphic region (5-HTTLPR), and neural structures using MRI. The current study aimed to bridge the gap between the relevant MRI literature on the effects of the 5-HTTLPR genotype and the research tradition focusing on transient lateralized changes of electrocortical activity in the prefrontal cortex using electroencephalography (EEG). Lateral shifts of EEG alpha asymmetry in response to an aversive film consisting of scenes of real injury and death were assessed in healthy participants (n = 165). To evaluate the specificity of the 5-HTTLPR effect, participants were also tested for the COMT Val158Met polymorphism which is linked to dopamine inactivation. While viewing the film, individuals homozygous for the 5-HTTLPR short allele displayed a clear lateral shift of dorsolateral frontal activity to the right, which was virtually absent in participants carrying the long allele. The heightened electrocortical response to the aversive stimulation and its direction indicates a greater propensity of s/s homozygotes to experience withdrawal oriented affect in response to negative emotion cues in the environment. Moreover, together with previous research the findings support the notion of a link between the serotonergic system and self-regulation related to avoidance motivation, and a link between the dopaminergic system and self-regulation related to approach motivation.

Dimensions of Temperament and Depressive Symptoms: Replicating a Three-Way Interaction

High negative emotionality (NE), low positive emotionality (PE), and low self-regulatory capacity (i.e., effortful control or EC) are related to depressive symptoms and furthermore, may moderate one another's relations to such symptoms. Indeed, preliminary evidence suggests they may operate in a three-way interaction (Dinovo & Vasey, 2011), but the replicability of that finding remains unknown. Therefore, we tested this NExPExEC interaction in association with depressive symptoms in 5 independent samples. This interaction was significant in 4 of the 5 samples and a combined sample and approached significance in the fifth sample. In contrast, the NExPExEC interaction was unrelated to general anxious symptoms and thus may be specific to symptoms of depression. Implications, directions for future research, and limitations are discussed.

Effects of an Early Experience Involving Training in a T-Maze Under either Denial or Receipt of Expected Reward through Maternal Contact

The mother is the most salient stimulus for the developing pups and a number of early experience models employ manipulation of the mother-infant interaction. We have developed a new model which in addition to changes in maternal behavior includes a learning component on the part of the pups. More specifically, pups were trained in a T-maze and either received (RER rats) or were denied (DER) the reward of maternal contact, during postnatal days 10-13. Pups of both experimental groups learn the T-maze, but the RER do so more efficiently utilizing a procedural-type of learning and memory with activation of the dorsal basal ganglia. On the other hand, the DER experience leads to activation of the hippocampus, prefrontal cortex, and amygdala in the pups. In adulthood, male DER animals exhibit better mnemonic abilities in the Morris water maze and higher activation of the hippocampus, while they have decreased brain serotonergic activity, exhibit a depressive-like phenotype and proactive aggressive behavior in the resident-intruder test. While male RER animals assume a reactive coping style in this test, and showed increased freezing during both contextual and cued memory recall following fear conditioning.

The neuromodulator of exploration: A unifying theory of the role of dopamine in personality

The neuromodulator dopamine is centrally involved in reward, approach behavior, exploration, and various aspects of cognition. Variations in dopaminergic function appear to be associated with variations in personality, but exactly which traits are influenced by dopamine remains an open question. This paper proposes a theory of the role of dopamine in personality that organizes and explains the diversity of findings, utilizing the division of the dopaminergic system into value coding and salience coding neurons (Bromberg-Martin et al., 2010). The value coding system is proposed to be related primarily to Extraversion and the salience coding system to Openness/Intellect. Global levels of dopamine influence the higher order personality factor, Plasticity, which comprises the shared variance of Extraversion and Openness/Intellect. All other traits related to dopamine are linked to Plasticity or its subtraits. The general function of dopamine is to promote exploration, by facilitating engagement with cues of specific reward (value) and cues of the reward value of information (salience). This theory constitutes an extension of the entropy model of uncertainty (EMU; Hirsh et al., 2012), enabling EMU to account for the fact that uncertainty is an innate incentive reward as well as an innate threat. The theory accounts for the association of dopamine with traits ranging from sensation and novelty seeking, to impulsivity and aggression, to achievement striving, creativity, and cognitive abilities, to the overinclusive thinking characteristic of schizotypy.

Familial transmission of parental mood disorders: unipolar and bipolar disorders in offspring

OBJECTIVES

Offspring of depressed parents are at increased risk for psychiatric disorders. Although bipolar disorder (BD) and major depressive disorder (MDD) are both found in the same families, it is not clear whether transmission to offspring of BD or MDD tends to occur from parents with the same mood disorder subtype. Our primary hypothesis was that the offspring of parents with BD would be at increased risk for BD and other comorbid disorders common to BD, such as anxiety and substance use, relative to the offspring of parents with MDD. The offspring of parents with BD versus those with MDD were also hypothesized to be at greater risk for externalizing disorders (i.e., conduct disorder, attention-deficit hyperactivity disorder, or antisocial personality disorder).

METHODS

Parents (n = 320) with mood disorders and their offspring (n = 679) were studied. Adult offspring were administered the Structured Clinical Interview for DSM-IV Axis I Disorders to establish the presence of psychopathology. Offspring aged 10-18 years were assessed using the School Aged Schedule for Affective Disorders and Schizophrenia, Present and Lifetime version, and parents of children under the age of ten completed the Child Behavioral Checklist. Data were examined using Cox proportional hazard regression.

RESULTS

There was no difference in hazard of mood disorders in the offspring of parents with BD as compared to the offspring of parents with MDD. However, a number of other parent and offspring characteristics increased the risk of mood, anxiety, externalizing, and substance use disorders in the offspring, including self-reported childhood abuse in the parent or offspring, offspring impulsive aggression, and the age at onset of parental mood disorder.

CONCLUSIONS

Mood disorders are highly familial, a finding that appears independent of whether the parent's condition is unipolar or bipolar, suggesting considerable overlap in the heritability of MDD and BD. Although parental characteristics had a limited influence on the risk of offspring psychopathology, reported childhood adversity, be it in the parent or child, is a harbinger of negative outcomes. These risk factors extend previous findings, and are consistent with diathesis-stress conceptualizations.

Impulsive responses to emotion as a transdiagnostic vulnerability to internalizing and externalizing symptoms

INTRODUCTION

This study explored the hypothesis that impulsive reactions to heightened emotion may reflect a transdiagnostic vulnerability to both externalizing and internalizing symptoms.

METHODS

A sample of undergraduates completed self-report measures of aggression, borderline personality disorder symptoms, anxiety symptoms, and alcohol problems, and a subset completed interviews that assessed suicidality. All participants also completed self-report measures relating to impulsivity. We predicted that emotion-reactive impulsivity, but not other aspects of impulsivity, would be related to the set of psychopathology symptoms.

RESULTS

Multiple regression analyses found that emotion-reactive impulsivity was uniquely related to each of the psychopathology scales, whereas non-emotion-relevant impulsivity was uniquely related only to alcohol problems.

CONCLUSION

Discussion focuses on limitations and clinical implications.

Major depressive disorder and impulsive reactivity to emotion: toward a dual-process view of depression

OBJECTIVE

Dual-process theories of behaviour have been used to suggest that vulnerability to depression involves elevated reactivity to emotions. This study tests that idea, examining self-reported reactivity.

DESIGN

Comparison between persons with at least one lifetime episode of major depressive disorder (lifetime MDD) and those without this diagnosis, controlling for symptoms of alcohol use (a potential externalizing confound) and current symptoms of depression (a potential state-dependent confound).

METHODS

Undergraduates (N = 120) completed a clinical interview to diagnose lifetime MDD and a series of self-reports bearing on diverse aspects of self-control, including reactivity to emotion. Thirty-four people were diagnosed with lifetime MDD; 86 did not meet criteria for MDD. The groups were then compared on three factors underlying the scales assessing self-control.

RESULTS

The MDD group had higher scores than controls on the two factors that reflect impulsive reactivity to diverse emotions, including emotions that are positive in valence. These effects were not explained by associations with either externalizing symptoms or current depressive symptoms.

CONCLUSIONS

Reflexive reactivity to emotions characterizes depression, in addition to some externalizing problems, and it may deserve study as a potential trans-diagnostic feature.

PRACTITIONER POINTS

Reflexive reactivity to emotions characterizes persons diagnosed with major depressive disorder. Findings suggest desirability of focusing treatment partly on management of reflexive reactions to emotions.

LIMITATION

Measures were self-reports, rather than behavioural responses to emotions.

Why social attachment and oxytocin protect against addiction and stress: Insights from the dynamics between ventral and dorsal corticostriatal systems

The present article advances a neurobiological model of the reciprocal associations between social attachment and drug abuse, and social attachment and chronic stress, as overlapping systems are involved in stress coping and social attachment. In terms of coping, responding to a novel stressor or challenge involves initial novelty processing and activation of learning mechanisms that allow habituation to the stressor through familiarization. Similarly, social attachments are initially formed by being attracted by rewarding properties of an as-yet novel individual, and subsequently developing feelings of attachment towards the familiarized individual. Attachment and familiarization increase the availability of "internal working models" for the control of behavior and emotion, which may explain why secure attachments are associated with increased resilience in the face of stress, accompanied by less reactive reward responding (i.e., increased resilience against drug addiction). The present article seeks to illuminate the role of the neuropeptide oxytocin, which may be involved in the overlapping mechanisms of stable attachment formation and stress coping by shifting processing from novelty and reward seeking to appreciation of familiarity. Oxytocin may accomplish this by facilitating a ventral-to-dorsal shift in activation in corticostriatal loops, which produces a shift from a reactive reward drive (wanting) to stable appreciation of familiar social aspects ("liking" or "loving"). The authors suggest that through dopaminergic, serotonergic and endogenous opioid mechanisms, oxytocin is involved in shifting the balance between wanting and liking in corticostriatal loops by facilitating consolidation of social information from ventral reactive reward systems to dorsal internal working models that aid in prospectively selecting optimal actions in the future, increasing resilience in the face of stress and addiction.

Ketamine elicits sustained antidepressant-like activity via a serotonin-dependent mechanism

RATIONALE

Behavioural antidepressant-like effects of ketamine have been reported in the forced swimming test (FST). The mechanisms mediating such effects are unknown.

OBJECTIVES

As serotonin (5-HT) is an important transmitter mediating antidepressant responsiveness in the FST, the influence of 5-HT depletion on the antidepressant-like effect of ketamine was assessed.

METHODS

The effect of ketamine (25 mg/kg, i.p., 1 or 24 h prior to test) was assessed in the FST in naive rats or animals subjected to 5-HT depletion, repeated stress or following a combination of 5-HT depletion and stress. Endogenous 5-HT was depleted using the tryptophan hydroxylase inhibitor para-chlorophenylalanine (3 × 150 mg/kg, i.p.). Stress was induced by physical restraint (2 h/day for 10 days).

RESULTS

In naive rats, ketamine administered 24 or 1 h prior to test produced a characteristic antidepressant-like reduction in immobility time in the FST. Depletion of 5-HT blocked this reduction in immobility when ketamine was administered 24 h prior FST, indicative of 5-HT dependency. The increase in immobility provoked by repeated restraint stress (2 h/day for 10 days) was blocked by ketamine when administered 24 h prior to FST, but this effect dissipated when animals were subjected to 5-HT depletion.

CONCLUSIONS

These observations are consistent with a role for 5-HT in mediating sustained antidepressant activity of ketamine in the FST. Molecular and cellular changes induced by ketamine may produce a rapid adaptation of 5-HT transmission which underlies the antidepressant response.

Approach and Avoidance Behaviour: Multiple Systems and their Interactions

Approach–avoidance theories describe the major systems that motivate behaviours in reaction to classes of appetitive (rewarding) and aversive (punishing) stimuli. The literature points to two major “avoidance” systems, one related to pure avoidance and escape of aversive stimuli, and a second, to behavioural inhibition induced by the detection of goal conflict (in addition, there is evidence for nonaffective behavioural constraint). A third major system, responsible for approach behaviour, is reactive to appetitive stimuli, and has several subcomponents. A number of combined effects of these systems are outlined. Finally, the hierarchical nature of behavioural control is delineated, including the role played by conscious awareness in behavioural inhibition.

Evaluation of the unique and specific contributions of dimensions of the triple vulnerability model to the prediction of DSM-IV anxiety and mood disorder constructs

The triple vulnerability model (Barlow, 2000, 2002) posits that three vulnerabilities contribute to the etiology of emotional disorders: (1) general biological vulnerability (i.e., dimensions of temperament such as neuroticism and extraversion); (2) general psychological vulnerability (i.e., perceived control over life stress and emotional states); (3) disorder-specific psychological vulnerability (e.g., thought-action fusion for OCD). Despite the prominence of this model, a comprehensive empirical evaluation has not yet been undertaken. The current study used structural equation modeling to test the triple vulnerability model in a large clinical sample (N=700), focusing on vulnerabilities for depression, social phobia, generalized anxiety disorder (GAD), and OCD. Specifically, we examined the incremental prediction of each level of the triple vulnerability model for each disorder, with the following putative disorder-specific psychological vulnerabilities: thought-action fusion (TAF) for OCD, the dysfunctional attitudes (DAS) for depression, and intolerance of uncertainty (IoU) for GAD. In the final model that included all three levels of vulnerabilities, neuroticism had significant direct effects on all four disorder constructs, and extraversion was inversely associated with depression and social phobia. However, perceived control was significantly associated with GAD and OCD only. Of the disorder-specific psychological vulnerabilities, TAF was significantly and specifically related to OCD. In contrast, DAS and IoU were not significant predictors of depression and GAD respectively, instead contributing to other disorders. The results are discussed in regard to structural models of the emotional disorders and the various roles of general and specific vulnerability dimensions in the onset, severity, and temporal course of psychopathology.

Influence of depression symptoms on history-independent reward and punishment processing

Prior research indicates that depressed individuals are less responsive to rewards and more sensitive to punishments than non-depressed individuals. This study examines decision-making under reward maximizing or punishment minimizing conditions among adults with low (n=47) or high (n=48) depression symptoms. We utilized a history-independent decision-making task where learning is experience-based and the participants' goal is to enhance immediate payoff. Results indicated a significant interaction between incentive condition (reward maximizing, punishment minimizing) and depression group. Within the low depression group, better performance was observed for reward maximization than punishment minimization. In contrast, within the high depression group, better performance was observed for punishment minimization than reward maximization. Further, the high depression group outperformed the low depression symptom group in the punishment minimization condition, but no depression group differences were observed in the reward maximization condition. Computational modeling indicated that the high depression group was more likely to choose options with the highest expected reward, particularly in the punishment condition. Thus, decision-making is improved for people with elevated depression symptoms when minimizing punishment relative to maximizing rewards.

Interactive contributions of self-regulation deficits and social motivation to psychopathology: unraveling divergent pathways to aggressive behavior and depressive symptoms

Poor self-regulation has been implicated as a significant risk factor for the development of multiple forms of psychopathology. This research examined the proposition that self-regulation deficits differentially predict aggressive behavior and depressive symptoms, depending on children's social approach versus avoidance motivation. A prospective, multiple-informant approach was used to test this hypothesis in 419 children (M age = 8.92, SD = 0.36). Parents rated children's inhibitory control. Children completed measures of social approach-avoidance motivation and depressive symptoms. Teachers rated children's aggressive behavior. As anticipated, poor inhibitory control predicted aggressive behavior in boys with high but not low approach motivation and low but not high avoidance motivation, whereas poor inhibitory control predicted depressive symptoms in girls with high but not low avoidance motivation. This research supports several complementary theoretical models of psychopathology and provides insight into the differential contributions of poor self-regulation to maladaptive developmental outcomes. The findings suggest the need for targeted intervention programs that consider heterogeneity among children with self-regulatory deficits.

Effortful control and parenting: associations with HPA axis reactivity in early childhood

While activation of the hypothalamic-pituitary-adrenal (HPA) axis is an adaptive response to stress, excessive HPA axis reactivity may be an important marker of childhood vulnerability to psychopathology. Parenting, including parent affect during parent-child interactions, may play an important role in shaping the developing HPA system; however, the association of parent affect may be moderated by child factors, especially children's emerging self-regulatory skills. We therefore tested the relationship between parent affectivity and 160 preschoolers' cortisol reactivity during a laboratory visit, examining children's effortful control (EC) as a moderator. Greater parent negative affectivity was related to greater initial and increasing cortisol over time, but only when children were low in EC. Higher parent positive affectivity was related to a higher baseline cortisol for children with low EC and lower baseline cortisol for children with high EC. Results indicate that children's EC moderates the extent to which parent affect shapes stress reactive systems in early childhood.

The role of parenting and dopamine D4 receptor gene polymorphisms in children's inhibitory control

Temperamental effortful control has important implications for children's development. Although genetic factors and parenting may influence effortful control, few studies have examined interplay between the two in predicting its development. The current study investigated associations between parenting and a facet of children's effortful control, inhibitory control (IC), and whether these associations were moderated by whether children had a 7-repeat variant of the DRD4 exon III VNTR. A community sample of 409 3-year-olds completed behavioural tasks to assess IC, and observational measures of parenting were also collected. Negative parenting was associated with lower child IC. The association between children's IC and positive parenting was moderated by children's DRD4 7-repeat status, such that children with at least one 7-repeat allele displayed lower IC than children without this allele when positive parenting was lower. These effects appeared to be primarily influenced by parent support and engagement. Results extend recent findings suggesting that some genetic polymorphisms may increase vulnerability to contextual influences.