Common Genetic Influences on Impulsivity Facets are Related to Goal Management, Psychopathology, and Personality

Impulsivity facets and substance use involvement: insights from genomic structural equation modeling

BACKGROUND

Impulsivity is a multidimensional trait associated with substance use disorders (SUDs), but the relationship between distinct impulsivity facets and stages of substance use involvement remains unclear.

METHODS

We used genomic structural equation modeling and genome-wide association studies (N = 79,729-903,147) to examine the latent genetic architecture of nine impulsivity traits and seven substance use (SU) and SUD traits.

RESULTS

We found that the SU and SUD factors were strongly genetically inter-correlated (rG=0.77) but their associations with impulsivity facets differed. Lack of premeditation, negative and positive urgency were equally positively genetically correlated with both the SU (rG=.0.30-0.50) and SUD (rG=0.38-0.46) factors; sensation seeking was more strongly genetically correlated with the SU factor (rG=0.27 versus rG=0.10); delay discounting was more strongly genetically correlated with the SUD factor (rG=0.31 versus rG=0.21); and lack of perseverance was only weakly genetically correlated with the SU factor (rG=0.10). After controlling for the genetic correlation between SU/SUD, we found that lack of premeditation was independently genetically associated with both the SU (β=0.42) and SUD factors (β=0.21); sensation seeking and positive urgency were independently genetically associated with the SU factor (β=0.48, β=0.33, respectively); and negative urgency and delay discounting were independently genetically associated with the SUD factor (β=0.33, β=0.36, respectively).

CONCLUSIONS

Our findings show that specific impulsivity facets confer risk for distinct stages of substance use involvement, with potential implications for SUDs prevention and treatment.

Testing a Multidimensional Factor Structure of the Self-Control Scale

The Self-Control Scale (SCS) is one of the most widely used measures in the clinical, personality, and social psychology fields. It is often treated as unidimensional, even though no research supports such a unidimensional factor structure. We tested the factor structure in an undergraduate sample as well as a community sample used for additional confirmatory analyses. Factors from the best-fitting confirmatory models were correlated with putatively related and distinct constructs to assess their (dis)similarities. Consistent with hypotheses, the best-fitting factor structure consisted of multiple, correlated factors; however, none of the factor solutions met pre-specified fit criteria. Several additional analyses were conducted beyond the preregistered analyses to find a reasonably fitting factor solution. Ultimately, study findings support a two-factor solution using the items of the Brief Self-Control Scale. Results are discussed for the full 36-item scale as well as the brief, 13-item scale. We conclude with lessons learned from a Registered Report focused on factor analysis.

Executive Function and Impulsivity Predict Distinct Genetic Variance in Internalizing Problems, Externalizing Problems, Thought Disorders, and Compulsive Disorders: A Genomic Structural Equation Modeling Study

Individual differences in self-control predict many health and life outcomes. Building on twin literature, we used genomic structural equation modeling to test the hypothesis that genetic influences on executive function and impulsivity predict independent variance in mental health and other outcomes. The impulsivity factor (comprising urgency, lack of premeditation, and other facets) was only modestly genetically correlated with low executive function (rg =.13). Controlling for impulsivity, low executive function was genetically associated with increased internalizing (βg =.15), externalizing (βg =.13), thought disorders (βg =.38), compulsive disorders (βg =.22), and chronotype (βg =.11). Controlling for executive function, impulsivity was positively genetically associated with internalizing (βg =.36), externalizing (βg =.55), body mass index (βg =.26), and insomnia (βg =.35), and negatively genetically associated with compulsive disorders (βg = -.17). Executive function and impulsivity were both genetically correlated with general cognitive ability and educational attainment. This work suggests that executive function and impulsivity are genetically separable and show independent associations with mental health.

Dual-systems models of the genetic architecture of impulsive personality traits: neurogenetic evidence of distinct but related factors

BACKGROUND

Dual-systems models, positing an interaction between two distinct and competing systems (i.e. top-down self-control, and bottom-up reward- or emotion-based drive), provide a parsimonious framework for investigating the interplay between cortical and subcortical brain regions relevant to impulsive personality traits (IPTs) and their associations with psychopathology. Despite recent developments in multivariate analysis of genome-wide association studies (GWAS), molecular genetic investigations of these models have not been conducted.

METHODS

Using IPT GWAS, we conducted confirmatory genomic structural equation models (GenomicSEM) to empirically evaluate dual-systems models of the genetic architecture of IPTs. Genetic correlations between dual-systems factors and relevant cortical and subcortical neuroimaging phenotypes (regional/structural volume, cortical surface area, cortical thickness) were estimated and compared.

RESULTS

GenomicSEM dual-systems models underscored important sources of shared and unique genetic variance between top-down and bottom-up constructs. Specifically, a dual-systems genomic model consisting of sensation seeking and lack of self-control factors demonstrated distinct but related sources of genetic influences (rg = 0.60). Genetic correlation analyses provided evidence of differential associations between dual-systems factors and cortical neuroimaging phenotypes (e.g. lack of self-control negatively associated with cortical thickness, sensation seeking positively associated with cortical surface area). No significant associations were observed with subcortical phenotypes.

CONCLUSIONS

Dual-systems models of the genetic architecture of IPTs tested were consistent with study hypotheses, but associations with relevant neuroimaging phenotypes were mixed (e.g. no associations with subcortical volumes). Findings demonstrate the utility of dual-systems models for studying IPT genetic influences, but also highlight potential limitations as a framework for interpreting IPTs as endophenotypes for psychopathology.

Validation of a Korean Version of the Short UPPS-P Impulsive Behavior Scale for Children

OBJECTIVE

Impulsivity is a multifaceted construct that plays an important role in various problem behaviors in children and adolescents. The purpose of this study was to validate a Korean version of the short UPPS-P Impulsive Behavior Scale for Children.

METHODS

Participants were 330 children (166 female) from 2 elementary schools in Korea and 94 attention deficit hyperactivity disorder (ADHD) children (23 female) from two major hospitals. The Korean short UPPS-P Impulsive Behavior Scale for Children (UPPS-P-C) (20 items), Child Behavior Checklist for Ages 6-18 (CBCL 6-18), and Barratt Impulsiveness Scale-11 (BIS-11) were administered. 107 children from the control group were retested 6 months later.

RESULTS

Confirmatory factor analysis (CFA) conducted in the control group supported a 5-factor hierarchical model in which 1) positive and negative urgency factors are loaded on a higher-order factor of general urgency; 2) lack of perseveration and lack of premeditation factors are loaded on a higher-order factor of lack of conscientiousness; and 3) sensation seeking remained as a separate dimension. Reliability analysis demonstrated that the 5 factors of the Korean short UPPS-P-C had acceptable internal consistency and test-retest reliability. Lack of premeditation and lack of perseveration subscales showed significant correlations with measures of problem behaviors in CBCL and all the subscales were correlated with the BIS-11. The ADHD group showed significantly higher scores in lack of premeditation, lack of perseveration, positive urgency, and negative urgency subscales.

CONCLUSION

This study indicates that the Korean version of short UPPS-P-C has adequate reliability and validity. It may be a valid tool to assess impulsivity of healthy children as well as ADHD.

Dual-systems models of the genetic architecture of impulsive personality traits: Neurogenetic evidence of distinct but related factors

Background

Dual-systems models provide a parsimonious framework for understanding the interplay between cortical and subcortical brain regions relevant to impulsive personality traits (IPTs) and their associations with psychiatric disorders. Despite recent developments in multivariate analysis of genome-wide association studies (GWAS), molecular genetic investigations of these models have not been conducted.

Methods

Using extant IPT GWAS, we conducted confirmatory genomic structural equation models (GenomicSEM) to empirically evaluate dual-systems models of the genetic architecture of IPTs. Genetic correlations between results of multivariate GWAS of dual-systems factors and GWAS of relevant cortical and subcortical neuroimaging phenotypes (regional/structural volume, cortical surface area, cortical thickness) were calculated and compared.

Results

Evaluation of GenomicSEM model fit indices for dual-systems models suggested that these models highlight important sources of shared and unique genetic variance between top-down and bottom-up constructs. Specifically, a dual-systems genomic model consisting of sensation seeking and lack of self-control factors demonstrated distinct but related sources of genetic influences ( r g =.60). Genetic correlation analyses provided evidence of differential associations between dual-systems factors and cortical neuroimaging phenotypes (e.g., lack of self-control negatively associated with cortical thickness, sensation seeking positively associated with cortical surface area). However, no significant associations were observed for subcortical phenotypes inconsistent with hypothesized functional localization of dual-systems constructs.

Conclusions

Dual-systems models of the genetic architecture of IPTs tested here demonstrate evidence of shared and unique genetic influences and associations with relevant neuroimaging phenotypes. These findings emphasize potential advantages in utilizing dual-systems models to study genetic influences for IPTs and transdiagnostic associations with psychiatric disorders.

When the UPPS-P Model of Impulsivity Meets a Revised Approach: The Development and Validation of the TRUE Multidimensional Impulsivity Scale

There is inconsistency in the measurement of impulsivity resulting from the diversity in its conceptualization. We aimed to develop a revised measure based on the Urgency, Premeditation (lack of), Perseverance (lack of), Sensation Seeking - Positive Urgency (UPPS-P) model (i.e., TRUE Multidimensional Impulsivity Scale; TRUE-MIS) considering the limitations and strengths of the existing measures. We conceptualized impulsivity as a personality trait referring to the inability to restrain one's urges without thinking about the future consequences in various contexts. A total of 535 adults (262 females, M = 34.1, SD = 12.7) participated in Study 1. Principal component analyses indicated a four-factor structure (internal urgency, social urgency, lack of premeditation, and lack of perseverance) with satisfactory internal consistency and validity evidence by significant relations with self-control. Confirmatory factor analysis in Study 2 confirmed the factor structure obtained in Study 1. Hierarchical linear regression analyses provided further validity evidence through establishing differential links between the subscales and Big Five personality traits, emotion regulation, depression, anxiety, and smartphone addiction in a sample of 556 adults (368 females, M = 24.0, SD = 7.4). Overall, TRUE-MIS is a valid and reliable measure of impulsivity addressing the arguments regarding the conceptual structure of the construct.

Gray matter volumetric correlates of dimensional impulsivity traits in children: Sex differences and heritability

Previous research investigated the cerebral volumetric correlates of impulsivity largely in moderate-sized samples and few have examined the distinct correlates of dimensions of impulsivity, sex differences, or heritability of the correlates. Here, we performed voxel-based morphometry analysis of data (n = 11,474; 5,452 girls, 9-10 years) curated from the Adolescent Brain Cognition Development project. In a linear regression with all five UPPS-P subscores as regressors and age in months, total intracranial volume, study site, and scanner model as covariates, higher levels of lack of premeditation, and sensation seeking were correlated with larger cortical and subcortical gray matter volumes (GMVs). In contrast, higher positive urgency was correlated with smaller GMVs in many of the same regions. The dimensional impulsivity traits also involved distinct volumetric correlates, with, for instance, sensation seeking and positive urgency specifically implicating bilateral caudate head/mid-cingulate cortex and bilateral lateral orbitofrontal cortex/left precentral gyrus, respectively. Boys relative to girls scored higher in all impulsivity dimensions. Girls relative to boys showed significantly stronger positive and negative correlations between sensation seeking and insula, putamen, and inferior frontal gyrus (IFG) GMVs and between positive urgency and cingulate cortex, insula, and IFG GMVs, respectively. With a subsample of twins, the dimensional impulsivity traits were weakly to moderately heritable in both girls and boys, and the GMV correlates were highly heritable in girls and boys combined. These findings collectively suggest shared and nonshared as well as sex differences in the cerebral volumetric bases of dimensional impulsivity traits and may facilitate research of externalizing psychopathology in children.

The Latent Genetic Structure of Impulsivity and Its Relation to Internalizing Psychopathology

Factor analyses suggest that impulsivity traits that capture tendencies to act prematurely or take risks tap partially distinct constructs. We applied genomic structure equation modeling to evaluate the genetic factor structure of two well-established impulsivity questionnaires, using published statistics from genome-wide association studies of up to 22,861 participants. We also tested the hypotheses that delay discounting would be genetically separable from other impulsivity factors and that emotionally triggered facets of impulsivity (urgency) would be those most strongly genetically correlated with an internalizing latent factor. A five-factor model best fitted the impulsivity data. Delay discounting was genetically distinct from these five factors. As expected, the two urgency subscales were most strongly related to an internalizing-psychopathology latent factor. These findings provide empirical genetic evidence that impulsivity can be broken down into distinct categories of differential relevance for internalizing psychopathology. They also demonstrate how measured genetic markers can be used to inform theories of psychology and personality.

Executive Functions and Impulsivity are Genetically Distinct and Independently Predict Psychopathology: Results from Two Adult Twin Studies

Laboratory executive function (EF) constructs, such as response inhibition, are often conceptually linked with self-report measures of impulsivity, yet their empirical correlations are low. We examined, in two twin studies (Ns=749 and 761 individuals with EF data), the phenotypic and genetic overlap of three EF latent variables (a Common EF factor predicting response inhibition, working memory updating, and mental set shifting tasks, and Updating- and Shifting-specific factors) with five impulsivity dimensions (negative and positive urgency, lack of premeditation and perseverance, and sensation seeking). In both samples, impulsivity dimensions only modestly correlated phenotypically (rs= -.20-.11) and genetically (rAs= -.44-.04) with Common EF. In both samples, Common EF and multiple impulsivity dimensions, particularly negative urgency, independently predicted Externalizing psychopathology, and multiple impulsivity dimensions, but not Common EF, predicted Internalizing psychopathology. These results suggest that EFs and self-reported impulsivity tap different aspects of control that are both relevant for psychopathology.