Personality dimensions as common and broadband-specific features for internalizing and externalizing disorders

Network structure of adolescent social, emotional, and behavioral difficulties and their differential relationships with suicidality

BACKGROUND

Social, emotional, and behavioral difficulties (SEBDs) tend to develop during adolescence. Their presence and especially co-occurrence induce numerous disrupting consequences, including suicidality. A recently developed network analysis is suitable to investigate the symptom-level structure of comorbid psychopathology. Rather than pairwise comorbidity networks, the current study investigated a comprehensive network of SEBDs at the symptom level and explored the differential relationships between symptoms of SEBDs and suicidality.

METHODS

Recruited from four public schools in China, a sample of adolescents (N = 6974, mean age = 15.84, 50.1% boys) were assessed with the Strengths and Difficulties Questionnaire (SDQ) and one suicidality-related item. The cross-sectional network structure of the SEBD symptoms was investigated. The differential associations between individual symptoms of SEBDs and suicidality were also explored with a relative importance analysis.

RESULTS

The results showed that constantly fidgeting, worry a lot, unhappy, down-hearted, tearful, and easily scared emerged as the most central symptoms in the network of SEBDs. Worry a lot, constantly fidgeting, lose my temper, and being bullied served as bridge symptoms, connecting various domains of SEBDs. In addition, the centrality of symptoms was positively associated with the variance shared with suicidality, with worry a lot and unhappy, down-hearted, and tearful explaining a large portion of the variance of suicidality.

CONCLUSIONS

Taken together, the results were indicative of close connections among emotional, hyperactivity-inattention, peer, and conduct aspects of adolescent mental health difficulties, as well as the central role of emotional difficulties in the SEBDs network.

Using Dispositions to Understand Otherwise Intractable Causal Pathways to Psychological Problems During Childhood and Adolescence

Studies of the genetic and environmental factors that make children more or less likely to develop distressing and impairing psychological problems, and studies of the psychobiological pathways through which these causal factors operate, have the goal of improving our understanding of the basic nature of psychological problems to develop better methods of prevention and treatment. For this reason, we have long had our eye on the prize of discovering the causes and psychobiological mechanisms underlying each dimension of psychological problems. There are compelling reasons, however, to seek a different and more achievable prize to understand psychological problems. Dimensions of psychological problems are both far too heterogeneous and too highly correlated to line up with distinct causal pathways. In contrast, a small number of orthogonal cognitive and socioemotional dispositional dimensions are correlated with psychological problems in revealing cross-cutting patterns. Each of these dispositions shares its independent causal pathways with psychological problems and help us understand the complex shared and heterogeneous nature of their causal processes. I outline a strategy for understanding the causes and mechanisms of psychological problems using studies of independently measured dispositions.

Perfectionistic Children and Their Parents: Is There Room for an Intergenerational Transmission? A Study of a Clinical Sample of Italian Children and Their Parents

Introduction: The relationship between maladaptive perfectionism and Internalizing (ID) and Externalizing Disorders (ED) in children needs to be better understood, along with the intergenerational transmission of these traits from parents to children. The present work aimed to share light on both these issues. Method: 39 children with ID, 19 with ED, and their parents were recruited*. The Multidimensional Perfectionism Scale, the Big Five Inventory, the Child and Adolescent Perfectionism Scale, and the Hierarchical Personality Inventory for Children were used. The association between parent personality and perfectionism traits and children’s perfectionism dimensions was evaluated through hierarchical regression analysis. Results: ID and ED groups did not differ significantly concerning perfectionism. Fathers presented higher scores than mothers in Self-Oriented Perfectionism, Other-Oriented Perfectionism, and Socially-Prescribed Perfectionism. Parents of children with ID report higher levels of Obedience in their children, while parents of children with ED reported higher levels of Creativity and Perseverance. Significant associations were found between perfectionism in parents and their children, as well as between perfectionism and the personality of children. Conclusion: Results suggest a transdiagnostic nature of Perfectionism and support the transgenerational transmission of the personality traits investigated.

Age-Related Variations of Genetic and Environmental Contributions to the Covariation of Fear, Distress and Externalizing Symptoms: A Twin Study in Childhood and Adolescence

The frequency with which Internalizing and Externalizing symptoms co-occur suggests that, behind both domains, there may be a common susceptibility represented by a general psychopathology factor. However, it's still unclear whether this common susceptibility is affected by age-related variations. Internalizing (i.e., Fear and Distress) and Externalizing symptoms were evaluated in 803 twin pairs from the population-based Italian Twin Registry. Model-fitting analysis was performed separately in the 6-14 and 15-18 age groups to estimate genetic and environmental contributions to the covariance among symptoms. For the 6-14 group, a multivariate Cholesky model best fitted the data, while, for the 15-18 group, the best fit was provided by a Common Pathway model in which nearly 50% of total variance of each trait was mediated by common genetic factors. Our findings support a common susceptibility behind Internalizing and Externalizing symptoms, mainly genetic in origin, that becomes more evident at the beginning of puberty.

Differences in microglia morphological profiles reflect divergent emotional temperaments: insights from a selective breeding model

Microglia play critical roles in healthy brain development and function, as well as the neuropathology underlying a range of brain diseases. Despite evidence for a role of microglia in affective regulation and mood disorders, little is known regarding how variation in microglia status relates to individual differences in emotionality. Using a selective breeding model, we have generated rat lines with unique temperamental phenotypes that reflect broad emotional traits: bred low responder rats (bLRs) are novelty-averse and model a passive coping style, whereas bred high responder rats (bHRs) are highly exploratory and model an active coping style. To identify a functional role of microglia in these phenotypes, we administered minocycline, an antibiotic with potent microglia inhibiting properties and observed shifts in forced swim, sucrose preference, and social interaction behaviors in bLRs. Using detailed anatomical analyses, we compared hippocampal microglia profiles of bHRs and bLRs and found that although the lines had similar numbers of microglia, selective breeding was associated with a shift in the morphological features of these cells. Specifically, microglia from bLRs were characterized by a hyper-ramified morphology, with longer processes and more complicated branching patterns than microglia from bHRs. This morphology is thought to reflect an early stage of microglia activation and suggests that bLR microglia are in a reactive state even when animals are not overtly challenged. Taken together, our results provide novel evidence linking variation in inborn temperament with differences in the baseline status of microglia and implicate a role for microglia in shaping enduring emotional characteristics.

Progression of externalizing disorders into anxiety disorders: Longitudinal transitions in the first three decades of life

BACKGROUND

There is a notable comorbidity between externalizing disorders and anxiety disorders, which may be explained by the co-occurrence of two prevalent early-onset disorders, by shared vulnerability and risk factors, or as evidence that one disorder group might be causally related to the other.

AIM

To investigate the longitudinal trajectories of externalizing disorders, their interplay with anxiety disorders, and putative predictors for symptom progression in youth.

METHODS

1053 adolescents (14-17 years) from the general population were assessed at baseline and prospectively at 2, 4, and 10-year follow-up using a standardized interview of mental disorders (DIA-X/M-CIDI) to assess "early" (oppositional-defiant disorder, conduct disorder, ADHD) and "late" (antisocial behavior, substance use disorders) externalizing disorders as well as anxiety disorders. Longitudinal associations and predictors for symptom progression were examined using Kaplan-Meier-analyses.

RESULTS

Lifetime prevalence of early externalizing disorders were 9.1% and 6.4% among those with and without any anxiety disorder. A late externalizing disorder was reported by 50.3% of those with an early externalizing disorder and in 26.6% of those with any anxiety disorder. Both early (HR: 1.5, 95%CI: 1.0-2.3) and late externalizing disorders (HR: 2.1, 95%CI: 1.7-2.6) were associated with incident anxiety disorders. Higher parental rejection, lower volitional inhibition, and higher volitional avoidance predicted incident anxiety disorders among those with early externalizing disorders.

DISCUSSION

Early externalizing disorders likely follow a homotypic continuity (to late externalizing disorders) and/or a heterotypic continuity to anxiety disorders, and thus appear as a useful target for prevention and early intervention.

Evidence for two genetically distinct pathways to co-occurring internalizing and externalizing problems in adolescence characterized by negative affectivity or behavioral inhibition

Unique pathways to adolescents' co-occurring internalizing/externalizing problems, a severe and common form of psychopathology, remain poorly delineated; this paucity of knowledge impedes the development of personalized interventions. We examined established measures of genetic risk and early childhood temperamental dimensions to clarify potentially distinct pathways to adolescents' co-occurring internalizing/externalizing problems. Participants were drawn from a longitudinal randomized controlled trial of a family-based intervention. The study employed multiple informants and methods, including observer ratings of toddlers' negative affectivity and behavioral inhibition, and primary caregiver ratings of toddlers' inhibitory control; internalizing and aggression polygenic risk scores (PRS) based on prior meta-genome-wide association studies (GWAS); and parents' and teachers' reports of adolescents' internalizing and externalizing problems. Higher levels of the aggression PRS indirectly predicted primary caregiver- and teacher-reported co-occurring problems relative to all other groups through greater early childhood negative affectivity. Lower levels of the aggression PRS and higher levels of the internalizing PRS indirectly predicted co-occurring problems relative to the externalizing "only" and low problem groups (primary caregivers only) through greater early childhood behavioral inhibition. Findings suggest two different genetic pathways to co-occurring problems that could lead to distinct prevention and intervention efforts. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Internalizing and externalizing psychopathology in middle age: genetic and environmental architecture and stability of symptoms over 15 to 20 years

BACKGROUND

Internalizing and externalizing psychopathology factors explain much of the covariance among psychiatric conditions, especially at the level of genetic risk. However, few studies have examined internalizing and externalizing factors in middle-aged samples, especially their ability to predict later symptoms across midlife. The goals of the current study were (i) to quantify the genetic and environmental influences on internalizing and externalizing psychopathology in individuals in their early 40s, and (ii) examine the extent to which these genetic and environmental influences predict self-reported measures of internalizing and externalizing symptoms 15-20 years later.

METHOD

1484 male twins completed diagnostic interviews of psychopathology at mean age 41 and self-reported measures of anxiety, depression, substance use, and related variables at up to two time-points in late middle age (mean ages 56 and 62).

RESULTS

Structural equation modeling of the diagnostic interviews confirmed that internalizing and externalizing factors accounted for most of the genetic variance in individual disorders, with substantial genetic (ra = 0.70) and environmental (re = 0.77) correlations between the factors. Internalizing psychopathology at age 41 was correlated with latent factors capturing anxiety, depression, and/or post-traumatic stress symptoms at ages 56 (r = 0.51) and 62 (r = 0.43). Externalizing psychopathology at age 41 was correlated r = 0.67 with a latent factor capturing aggression, tobacco use, and alcohol use at age 56. Stability of both factors was driven by genetic influences.

CONCLUSIONS

These findings demonstrate the considerable stability of internalizing and externalizing psychopathology symptoms across middle age, especially their genetic influences. Diagnostic interviews effectively predict self-reported symptoms and behaviors 15-20 years later.

Redefining phenotypes to advance psychiatric genetics: Implications from hierarchical taxonomy of psychopathology

Genetic discovery in psychiatry and clinical psychology is hindered by suboptimal phenotypic definitions. We argue that the hierarchical, dimensional, and data-driven classification system proposed by the Hierarchical Taxonomy of Psychopathology (HiTOP) consortium provides a more effective approach to identifying genes that underlie mental disorders, and to studying psychiatric etiology, than current diagnostic categories. Specifically, genes are expected to operate at different levels of the HiTOP hierarchy, with some highly pleiotropic genes influencing higher order psychopathology (e.g., the general factor), whereas other genes conferring more specific risk for individual spectra (e.g., internalizing), subfactors (e.g., fear disorders), or narrow symptoms (e.g., mood instability). We propose that the HiTOP model aligns well with the current understanding of the higher order genetic structure of psychopathology that has emerged from a large body of family and twin studies. We also discuss the convergence between the HiTOP model and findings from recent molecular studies of psychopathology indicating broad genetic pleiotropy, such as cross-disorder SNP-based shared genetic covariance and polygenic risk scores, and we highlight molecular genetic studies that have successfully redefined phenotypes to enhance precision and statistical power. Finally, we suggest how to integrate a HiTOP approach into future molecular genetic research, including quantitative and hierarchical assessment tools for future data-collection and recommendations concerning phenotypic analyses. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Are rumination and neuroticism genetically or environmentally distinct risk factors for psychopathology?

Neuroticism, a dispositional trait of heightened negative emotionality, is a vulnerability factor for psychopathology. Given neuroticism's strong association with rumination, a repetitive thought pattern that intensifies and prolongs emotions, some question whether these constructs capture the same or unique information about vulnerability for psychopathology. The present study examined whether neuroticism is genetically and environmentally distinct from two clinically relevant ruminative subtypes-anger and depressive rumination-and whether genetic and environmental influences specific to rumination versus shared with neuroticism overlap with internalizing and externalizing psychopathology. These analyses were conducted on 439 same-sex twin pairs in the Colorado Longitudinal Twin study. Rumination and neuroticism latent variables were created from multiple rumination questionnaires administered at age 23 and shortened Eysenck Personality Questionnaires administered at ages 17 and 21, respectively. Lifetime psychopathology symptoms, assessed by two structured clinical interviews, were used to create ordinal composite variables. Multivariate Cholesky decompositions indicated that neuroticism, anger rumination, and depressive rumination have common genetic and nonshared environmental influences but are differentiated by nonshared environmental influences specific to each ruminative subtype. Genetic influences common to rumination and neuroticism explained considerable variance in internalizing psychopathology, suggesting possible genetic mediation or common genetic causes. Genetic and environmental influences on externalizing psychopathology did not substantially overlap with those on neuroticism and rumination. These findings suggest that rumination and neuroticism share most genetic influences yet are influenced by distinct environmental influences. Furthermore, our results indicate that a comprehensive understanding of transdiagnostic risk factors must include an examination of both genetic and environmental influences. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Associations Between Neuroticism and Executive Function Outcomes: Response Inhibition and Sustained Attention on a Continuous Performance Test

There are known relationships between psychopathology, personality, and executive function (EF), though the association between personality and EF, independent of psychopathology, remains understudied. The present study investigated relationships between Five Factor Model personality traits and indices of response inhibition, sustained attention, and response variability on a continuous performance test (CPT) among 50 healthy adults (male = 27, female = 23; Mage = 19.9 years, range 18–24 years) of primarily Caucasian descent (58.0%). Participants performed an open-source CPT, the Psychology Experiment Building Language Battery Test of Attentional Vigilance (TOAV), and completed self-ratings of conscientiousness, extraversion, and neuroticism on an inventory developed from the public-domain International Personality Item Pool. After controlling for the influences of age, gender, and other personality traits, neuroticism was significantly associated with faster error reaction time and a higher frequency of multiple responses. Neuroticism was also nominally predictive of more frequent commission errors and faster correct and mean reaction time. The present findings indicate that neuroticism is associated with error-prone behavioral performance on a CPT, suggesting that a propensity to experience negative emotions may manifest as impulsivity and hyperactivity on performance-based measures of EF.

Genetic and Environmental Associations Among Executive Functions, Trait Anxiety, and Depression Symptoms in Middle Age

Multiple executive functions (EFs) are associated with trait anxiety and depression symptoms, but it is unclear how genetic and/or environmental factors account for these associations, and if they are explained by general variance underlying multiple EFs (i.e., Common EF). In this study, 1207 male twins completed seven EF tasks and measures of trait anxiety and depression symptoms at average age 62. The Common EF factor was associated with both anxiety (r= -.25) and depression symptoms (r= -.35). Anxiety and depression had near complete genetic overlap (r g=.96). Genetic influences shared with depression accounted for 83% of the phenotypic correlation between anxiety and Common EF. For depression, the phenotypic correlation with Common EF was explained by genetic influences shared with anxiety (69%), but also nonshared environmental influences distinct from anxiety (20%). These results suggest that genetic influences on Common EF play a role in the observed genetic overlap between anxiety and depression.

Do executive functions explain the covariance between internalizing and externalizing behaviors?

This study examined whether executive functions (EFs) might be common features of internalizing and externalizing behavior problems across development. We examined relations between three EF latent variables (a common EF factor and factors specific to updating working memory and shifting sets), constructed from nine laboratory tasks administered at age 17, to latent growth intercept (capturing stability) and slope (capturing change) factors of teacher- and parent-reported internalizing and externalizing behaviors in 885 individual twins aged 7 to 16 years. We then estimated the proportion of intercept-intercept and slope-slope correlations predicted by EF as well as the association between EFs and a common psychopathology factor (P factor) estimated from all 9 years of internalizing and externalizing measures. Common EF was negatively associated with the intercepts of teacher-rated internalizing and externalizing behavior in males, and explained 32% of their covariance; in the P factor model, common EF was associated with the P factor in males. Shifting-specific was positively associated with the externalizing slope across sex. EFs did not explain covariation between parent-rated behaviors. These results suggest that EFs are associated with stable problem behavior variation, explain small proportions of covariance, and are a risk factor that that may depend on gender.

Normative and Maladaptive Personality Trait Models of Mood, Psychotic, and Substance Use Disorders

The Personality Inventory for DSM-5 (PID-5) is a questionnaire developed to assess the five domains represented in the alternative model for personality disorders proposed in Section III of the DSM-5. This study examined the ability of the PID-5 to distinguish between different mental disorders compared to a questionnaire measure of the five-factor model (FFM) of normative personality. The study included the administration of the PID-5 and Revised NEO Personality Inventory (NEO PI-R), a measure of the FFM, to treatment-seeking individuals with Depressive, Bipolar, Psychotic, and Alcohol Use Disorders (AUD). Diagnostic groups were compared at the domain level of PID-5 and NEO PI-R, with sex and age as covariates. The main findings on the PID-5 included higher Detachment scores for Bipolar and Depressive Disorders than Psychotic and AUDs, lower Psychoticism/higher Disinhibition scores for the AUD group compared to all other groups, and lower Negative Affect for the Psychotic Disorders versus AUD group. On the NEO PI-R, the AUD diagnostic group was associated with lower Conscientiousness and Agreeableness scores compared to all other groups, and lower Neuroticism scores than the Bipolar and Depressive groups. Group pairwise comparisons did not appear to show many differences between the PID-5 and NEO PI-R. The results suggest that the alternative DSM-5 model for personality disorders may have clinical utility in distinguishing personality profiles between diagnostic groups. These findings emphasize the importance of additional research on the capacity of maladaptive personality to contribute to the assessment of differential diagnoses.

A Psychometric Examination of the Pathological Obsessive Compulsive Personality Scale (POPS): Initial Study in an Undergraduate Sample

Obsessive-compulsive personality disorder (OCPD) has been subject to numerous definition and classification changes, which has contributed to difficulties in reliable measurement of the disorder. Consequently, OCPD measures have yielded poor validity and inconsistent prevalence estimates. Reliable and valid measures of OCPD are needed. The aim of the current study was to examine the factor structure and psychometric properties of the Pathological Obsessive Compulsive Personality Scale (POPS). Participants (N = 571 undergraduates) completed a series of self-report measures online, including the POPS. Confirmatory factor analysis was used to compare the fit of unidimensional, five factor, and bifactor models of the POPS. Convergent and divergent validity were assessed in relation to other personality dimensions. A bifactor model provided the best fit to the data, indicating that the total POPS scale and four subscales can be scored to obtain reliable indicators of OCPD. The POPS was most strongly associated with a disorder-specific measure of OCPD, however there were also positive associations with theoretically disparate constructs, thus further research is needed to clarify validity of the scale.

The role of emotion regulation in predicting personality dimensions

Dimensional models of personality have been widely acknowledged in the field as alternatives to a trait-based system of nomenclature. While the importance of dimensional models has been established, less is known about the constructs underlying these personality dimensions. Emotion regulation is one such potential construct. The goal of the current study was to examine the relationship between personality dimensions and emotion regulation. More specifically, the predictive capacity of emotion regulation in accounting for personality dimensions and symptoms on the Schedule for Nonadaptive and Adaptive Personality-2 above and beyond a measure of general distress was evaluated. Emotion regulation was found to be predictive of most personality dimensions and symptoms of most personality disorders. Consistent with hypotheses, emotion regulation variables associated with undercontrol of emotions were most predictive of traits associated with Cluster B personality disorders whereas Cluster A and C traits were most associated with emotion regulation related to overcontrol of emotions. These findings provide preliminary evidence that some personality dimensions never assessed in relation to emotion regulation are strongly predicted by emotion regulation variables. Thus, the present study facilitates an initial step in understanding the relationship between personality dimensions and a multidimensional model of emotion regulation. Copyright © 2017 John Wiley & Sons, Ltd.

Genetic and Environmental Associations Between Procrastination and Internalizing/Externalizing Psychopathology

Recent work on procrastination has begun to unravel the genetic and environmental correlates of this problematic behavior. However, little is known about how strongly procrastination is associated with internalizing and externalizing psychopathology, and the extent to which shared genetic/environmental factors or relevant personality constructs (e.g., fear of failure, impulsivity, and neuroticism) can inform the structure of these associations. The current study examined data from 764 young adult twins who completed questionnaires assessing procrastination and personality and structured interviews regarding psychopathology symptoms. Results indicated that procrastination was positively correlated with both internalizing and externalizing latent variables, and that these correlations were driven by shared genetic influences. Moreover, the association between procrastination and internalizing was accounted for by fear of failure and neuroticism, whereas the association between procrastination and externalizing was primarily explained by impulsivity. The role of procrastination in psychopathology is discussed using a framework that highlights common and broadband-specific variance.

Transdiagnostic factors and pathways to multifinality: The error-related negativity predicts whether preschool irritability is associated with internalizing versus externalizing symptoms at age 9

There is increasing interest among developmental psychopathologists in broad transdiagnostic factors that give rise to a wide array of clinical presentations (multifinality), but little is known about how these processes lead to particular psychopathological manifestations over the course of development. We examined whether individual differences in the error-related negativity (ΔERN), a neural indicator of error monitoring, predicts whether early persistent irritability, a prototypical transdiagnostic construct, is associated with later internalizing versus externalizing outcomes. When children were 3 years old, mothers were interviewed about children's persistent irritability and completed questionnaires about their children's psychopathology. Three years later, EEG was recorded while children performed a go/no-go task to measure the ΔERN. When children were approximately 9 years old, mothers again completed questionnaires about their children's psychopathology. The results indicated that among children who were persistently irritable at age 3, an enhanced or more negative ΔERN at age 6 predicted the development of internalizing symptoms at age 9, whereas a blunted or smaller ΔERN at age 6 predicted the development of externalizing symptoms. Our results suggest that variation in error monitoring predicts, and may even shape, the expression of persistent irritability and differentiates developmental trajectories from preschool persistent irritability to internalizing versus externalizing outcomes in middle to late childhood.

Pre-ejection period reactivity to reward is associated with anhedonic symptoms of depression among adolescents

Pre-ejection period (PEP) reactivity to reward has been posited as a specific index of behavioral approach and incentive motivation, suggesting it might be uniquely associated with the affective and motivational deficits of anhedonia. This study evaluated PEP reactivity to a reward task as a predictor of depressive symptoms among adolescents, examining global depressive symptoms as well as specific anhedonic and nonanhedonic symptoms clusters. Participants included 76 adolescents, ages 11-15 years (52% female). This study found marginal support for an association between PEP reactivity to reward and concurrent anhedonia symptoms, but no association with nonanhedonic or the global scale. Findings are discussed in terms of potential associations between peripheral psychophysiological measures and dopaminergic functioning and also the utility of this measure for future research on anhedonia.

A hierarchical causal taxonomy of psychopathology across the life span

We propose a taxonomy of psychopathology based on patterns of shared causal influences identified in a review of multivariate behavior genetic studies that distinguish genetic and environmental influences that are either common to multiple dimensions of psychopathology or unique to each dimension. At the phenotypic level, first-order dimensions are defined by correlations among symptoms; correlations among first-order dimensions similarly define higher-order domains (e.g., internalizing or externalizing psychopathology). We hypothesize that the robust phenotypic correlations among first-order dimensions reflect a hierarchy of increasingly specific etiologic influences. Some nonspecific etiologic factors increase risk for all first-order dimensions of psychopathology to varying degrees through a general factor of psychopathology. Other nonspecific etiologic factors increase risk only for all first-order dimensions within a more specific higher-order domain. Furthermore, each first-order dimension has its own unique causal influences. Genetic and environmental influences common to family members tend to be nonspecific, whereas environmental influences unique to each individual are more dimension-specific. We posit that these causal influences on psychopathology are moderated by sex and developmental processes. This causal taxonomy also provides a novel framework for understanding the heterogeneity of each first-order dimension: Different persons exhibiting similar symptoms may be influenced by different combinations of etiologic influences from each of the 3 levels of the etiologic hierarchy. Furthermore, we relate the proposed causal taxonomy to transdimensional psychobiological processes, which also impact the heterogeneity of each psychopathology dimension. This causal taxonomy implies the need for changes in strategies for studying the etiology, psychobiology, prevention, and treatment of psychopathology. (PsycINFO Database Record

The temporal stability of the bifactor model of comorbidity: An examination of moderated continuity pathways

BACKGROUND

Structural models of psychopathology indicate that common mental disorder comorbidity reflects latent transdiagnostic factors. Multiple studies have replicated transdiagnostic internalizing (mood and anxiety disorders) and externalizing (substance use, antisociality-, and impulsivity-related disorders) factors; other studies support distress and fear sub-factors of internalizing. These factors show a high degree of temporal stability. Recently, a bifactor conceptualization of multivariate comorbidity has emerged, positing the existence of an orthogonal general psychopathology factor that saturates all diagnoses in addition to internalizing/distress/fear and externalizing, although no studies have examined the temporal stability of the factors in this competing model over time among adults.

METHOD

In a large, two-wave nationally representative sample (N=43,093), we investigated the structure of the bifactor model and examined all potential within- and between-factor stability pathways in a structural equation modeling framework.

RESULTS

In general, within-domain stability (e.g., Wave 1 general factor predicting Wave 2 general factor) was high, while between-domain pathways (e.g., Wave 1 general factor predicting the Wave 2 externalizing factor) did not differ significantly from zero. We then tested possible age and gender moderation of factor stability, finding that the stability for all factors, except fear, significantly differed across demographic sub-groups. However, these differences were not clinically meaningful.

CONCLUSIONS

Results indicated that bifactor model factors show varying degrees of temporal stability, with lowest comorbidity continuity over time reflecting distress stability. Findings are discussed with regard to recent evidence that the general factor may, to some extent, represent the negative emotionality captured by internalizing/distress in correlated two- and three-factor solutions.

An examination of the developmental propensity model of conduct problems

The present study tested specific hypotheses advanced by the developmental propensity model of the etiology of conduct problems in the Colorado Longitudinal Twin Study, a prospective, longitudinal, genetically informative sample. High negative emotionality, low behavioral inhibition, low concern and high disregard for others, and low cognitive ability assessed during toddlerhood (age 14 to 36 months) were examined as predictors of conduct problems in later childhood and adolescence (age 4 to 17 years). Each hypothesized antisocial propensity dimension predicted conduct problems, but some predictions may be context specific or due to method covariance. The most robust predictors were observed disregard for others (i.e., responding to others' distress with active, negative responses such as anger and hostility), general cognitive ability, and language ability, which were associated with conduct problems reported by parents, teachers, and adolescents, and change in observed negative emotionality (i.e., frustration tolerance), which was associated with conduct problems reported by teachers and adolescents. Furthermore, associations between the most robust early predictors and later conduct problems were influenced by the shared environment rather than genes. We conclude that shared environmental influences that promote disregard for others and detract from cognitive and language development during toddlerhood also predispose individuals to conduct problems in later childhood and adolescence. The identification of those shared environmental influences common to early antisocial propensity and later conduct problems is an important future direction, and additional developmental behavior genetic studies examining the interaction between children's characteristics and socializing influences on conduct problems are needed. (PsycINFO Database Record

Emotion dysregulation, psychological inflexibility, and shame as explanatory factors between neuroticism and depression

BACKGROUND

The association between neuroticism and depression is well documented. However, neuroticism is a general risk factor associated with many forms of psychopathology, such as anxiety, eating, and personality disorders. Past research has suggested that other factors may mediate the relationship between neuroticism and symptoms of particular disorders.

METHODS

Self-report questionnaires measuring neuroticism, emotion dysregulation, psychological inflexibility, shame, and symptoms of depression were administered to 105 inpatient adolescents (aged 12-17). The current study examined three factors (emotion dysregulation difficulties, psychological inflexibility, and shame) as concurrent mediators of the neuroticism/depression association.

RESULTS

Neuroticism was significantly associated with depression, as expected. Neuroticism was also associated with emotion dysregulation and psychological inflexibility, which, in combination, fully mediated the association between neuroticism and depression. Shame was not significantly associated with neuroticism or depression, when controlling for anxiety, externalizing, sex, and age. Follow-up analyses examined six sub-factors of emotion dysregulation as multiple mediators of the neuroticism/depression association. Goal directed behavior, lack of emotion regulation strategies, and impulse control were significant mediators, controlling for the other three emotion dysregulation sub-factors.

LIMITATIONS

The study is limited by the cross sectional design, sample size, and self-report measurement.

CONCLUSIONS

Despite limitations, this study demonstrated that the link between neuroticism and depression is explained by both emotion dysregulation and psychological inflexibility and that specific emotion dysregulation facets may be at play in adolescent depression.

Testing models of psychopathology in preschool-aged children using a structured interview-based assessment

A number of studies have found that broadband internalizing and externalizing factors provide a parsimonious framework for understanding the structure of psychopathology across childhood, adolescence, and adulthood. However, few of these studies have examined psychopathology in young children, and several recent studies have found support for alternative models, including a bi-factor model with common and specific factors. The present study used parents' (typically mothers') reports on a diagnostic interview in a community sample of 3-year old children (n = 541; 53.9 % male) to compare the internalizing-externalizing latent factor model with a bi-factor model. The bi-factor model provided a better fit to the data. To test the concurrent validity of this solution, we examined associations between this model and paternal reports and laboratory observations of child temperament. The internalizing factor was associated with low levels of surgency and high levels of fear; the externalizing factor was associated with high levels of surgency and disinhibition and low levels of effortful control; and the common factor was associated with high levels of surgency and negative affect and low levels of effortful control. These results suggest that psychopathology in preschool-aged children may be explained by a single, common factor influencing nearly all disorders and unique internalizing and externalizing factors. These findings indicate that shared variance across internalizing and externalizing domains is substantial and are consistent with recent suggestions that emotion regulation difficulties may be a common vulnerability for a wide array of psychopathology.

Increasing Relationship Between Negative Emotionality and Conduct Problems During Childhood: A Cross-Sectional Behavioral Genetic Analysis

Age difference in the etiology of the relationship between childhood negative emotionality (NE) and conduct problems (CP) has not been previously investigated. Mothers of 662 pairs of twins completed questions on the emotionality (NE) scale of the EAS temperament survey and the CP scale of the Strengths and Difficulties Questionnaires (SDQ) via a telephone interview. Twin data were analyzed separately in younger (ages 3 to 7 years; mostly pre-schoolers) and older children (ages 8 to 13 years; mostly elementary school children). The phenotypic correlation between NE and CP increased from 0.33 among younger twins to 0.43 among older twins. Bivariate model-fitting analysis was performed to determine age difference in the etiology of the relationship between NE and CP. Among younger twins, the correlation between NE and CP was entirely explained by additive genetic factors common to NE and CP. Among older children, however, a small but significant amount of unique environmental correlation emerged to account for about 47% of the phenotypic correlation between NE and CP. The remaining 53% of the phenotypic correlation was due to shared additive genetic factors. We speculate that environmental factors associated with school adjustment may exert influences on the relationship between NE and CP among elementary school children.

NCAM1-TTC12-ANKK1-DRD2 gene cluster and the clinical and genetic heterogeneity of adults with ADHD

Dysfunctions of the dopaminergic system have been implicated on the etiology of Attention Deficit/Hyperactivity Disorder (ADHD). Meta-analyses addressing the association of the dopamine receptor D2 (DRD2) gene and ADHD were inconclusive due to excessive heterogeneity across studies. Both the great phenotypic heterogeneity of ADHD and the complexity of the genomic region where DRD2 is located could contribute to the inconsistent findings. Most previous DRD2 studies focused on the well-known Taq1A (rs1800497) SNP, which is actually placed in a neighbor gene (ANKK1). These two genes, together with NCAM1 and TTC12, form the NTAD gene cluster on Chr11q22-23. In order to address the reasons for the high heterogeneity previously reported on DRD2 effects on ADHD, this study investigates the role of NTAD variants on ADHD susceptibility in adults and on the modulation of comorbidity and personality profiles in these patients. Functional polymorphisms from NTAD were analyzed, both individually and in haplotypes, on a sample of 520 adults with ADHD and 630 non-ADHD controls. No direct association of NTAD variants with ADHD susceptibility itself was observed. However, different NTAD polymorphisms and haplotypes were associated to various phenotypes relevant to the clinical heterogeneity of ADHD, including Major Depressive Disorder, Generalized Anxiety Disorder, and Harm Avoidance and Persistence temperament scores. Therefore, these findings represent a possible explanation for the multiple conflicting findings regarding polymorphisms in this genomic region in psychiatry. The NTAD cluster may comprise a variety of independent molecular influences on various brain and behavior characteristics eventually associated with ADHD comorbidities and personality traits. © 2015 Wiley Periodicals, Inc.

The Brave New World of Personality Disorder-Trait Specified: Effects of Additional Definitions on Coverage, Prevalence, and Comorbidity

The alternative dimensional model for personality disorder (PD) in DSM-5, Section III (DSM-5-III) includes two main criteria: (A) personality-functioning impairment, and (B) personality-trait pathology; provides specific functioning-and-trait criteria for six PD-type diagnoses; and introduces PD-trait specified (PD-TS), which requires meeting the general PD criteria and not meeting criteria for any specific PD type. We termed this Simple PD-TS and developed two additional definitions: Mixed PD-TS, meeting criteria for one or two PD types and having five or more additional pathological traits; and Complex PD-TS, meeting criteria for three or more PD types. In a mixed sample of 165 outpatients and 215 community adults screened to be at high-risk for PD, we investigated the effect of these additional definitions on prevalence, coverage, comorbidity, and within-diagnosis heterogeneity, and conclude that eliminating the PD-type diagnoses and thus having PD-TS as the only PD diagnosis would be both more parsimonious and more useful clinically.

Comorbidity Among Dimensions of Childhood Psychopathology: Converging Evidence from Behavior Genetics

In this article, we review evidence from recent behavior genetic studies that examined the covariance among common childhood psychopathological conditions and tested specific hypotheses regarding common and broadband-specific underlying features of childhood psychopathology. Specifically, we review the distinction between internalizing and externalizing disorders, the support for the generalist genes and specialist environments model, negative emotionality as a heritable underlying feature common to both internalizing and externalizing disorders, and daring as a heritable broadband-specific underlying feature that distinguishes externalizing disorders from internalizing disorders. We also discuss the implications of research in the search for specific genes that influence childhood psychopathology and suggest avenues for new research.