Behavioral disinhibition and the development of substance-use disorders: findings from the Minnesota Twin Family Study

Getting closer to social interactions using electroencephalography in developmental cognitive neuroscience

The field of developmental cognitive neuroscience is advancing rapidly, with large-scale, population-wide, longitudinal studies emerging as a key means of unraveling the complexity of the developing brain and cognitive processes in children. While numerous neuroscientific techniques like functional magnetic resonance imaging (fMRI), functional near-infrared spectroscopy (fNIRS), magnetoencephalography (MEG), and transcranial magnetic stimulation (TMS) have proved advantageous in such investigations, this perspective proposes a renewed focus on electroencephalography (EEG), leveraging underexplored possibilities of EEG. In addition to its temporal precision, low costs, and ease of application, EEG distinguishes itself with its ability to capture neural activity linked to social interactions in increasingly ecologically valid settings. Specifically, EEG can be measured during social interactions in the lab, hyperscanning can be used to study brain activity in two (or more) people simultaneously, and mobile EEG can be used to measure brain activity in real-life settings. This perspective paper summarizes research in these three areas, making a persuasive argument for the renewed inclusion of EEG into the toolkit of developmental cognitive and social neuroscientists.

Variants of the P3 event-related potential operate as indicators of distinct mechanisms contributing to problematic alcohol use

Considerable research has linked relative reduction in the amplitude of the P3 event-related potential (ERP) during cognitive task performance (i.e., Target-P3) with increased risk of alcohol-related problems. A separate literature indicates that a relative increase in the amplitude of the P3 elicited by cues signaling alcohol availability (i.e., ACR-P3) also is associated with alcohol use and problems. To date, no research has integrated these seemingly discrepant findings. Here, we aimed to demonstrate that P3 amplitudes elicited in different task contexts reflect distinct domains of functioning relevant to problematic alcohol involvement (PAI), and therefore can inform heterogeneity in the etiology of PAI. 156 emerging adults (61% women; 88% White/Non-Hispanic) completed a mental rotation task and a picture-viewing task while ERPs were recorded. Participants also completed questionnaire measures of trait disinhibition, alcohol use, and alcohol-related problems. Findings from regression analyses indicated that (a) Target-P3 was negatively associated and ACR-P3 was positively associated with a PAI latent variable; (b) the two P3s accounted for unique variance in PAI, beyond that accounted for by recent drinking; and (c) the association between Target-P3 and PAI-but not ACR-P3 and PAI-was statistically mediated by trait disinhibition. The present findings highlight the unique contributions of distinct functional domains associated with disinhibition and incentive salience in the etiology of PAI. Moreover, findings are consistent with a nuanced understanding of the P3 ERP, whereby its specific meaning varies according to the task context in which it is elicited.

A genetically informed longitudinal study of early-life temperament and childhood aggression

The present study examined the longitudinal associations between three dimensions of temperament - activity, affect-extraversion, and task orientation - and childhood aggression. Using 131 monozygotic and 173 dizygotic (86 same-sex) twin pairs from the Louisville Twin Study, we elucidated the ages, from 6 to 36 months, at which each temperament dimension began to correlate with aggression at age 7. We employed latent growth modeling to show that developmental increases (i.e., slopes) in activity were positively associated with aggression, whereas increases in affect-extraversion and task orientation were negatively associated with aggression. Genetically informed models revealed that correlations between temperament and aggression were primarily explained by common genetic variance, with nonshared environmental variance accounting for a small proportion of each correlation by 36 months. Genetic variance explained the correlations of the slopes of activity and task orientation with aggression. Nonshared environmental variance accounted for almost half of the correlation between the slopes of affect-extraversion and aggression. Exploratory analyses revealed quantitative sex differences in each temperament-aggression association. By establishing which dimensions of temperament correlate with aggression, as well as when and how they do so, our work informs the development of future child and family interventions for children at highest risk of aggression.

Cognitive abilities are associated with rapid dynamics of electrophysiological connectome states

Time-varying changes in whole-brain connectivity patterns, or connectome state dynamics, hold significant implications for cognition. However, connectome dynamics at fast (> 1Hz) timescales highly relevant to cognition are poorly understood due to the dominance of inherently slow fMRI in connectome studies. Here, we investigated the behavioral significance of rapid electrophysiological connectome dynamics using source-localized EEG connectomes during resting-state (N=926, 473 females). We focused on dynamic connectome features pertinent to individual differences, specifically those with established heritability: Fractional Occupancy (i.e., the overall duration spent in each recurrent connectome state) in beta and gamma bands, and Transition Probability (i.e., the frequency of state switches) in theta, alpha, beta, and gamma bands. Canonical correlation analysis found a significant relationship between the heritable phenotypes of sub-second connectome dynamics and cognition. Specifically, principal components of Transition Probabilities in alpha (followed by theta and gamma bands) and a cognitive factor representing visuospatial processing (followed by verbal and auditory working memory) most notably contributed to the relationship. We conclude that the specific order in which rapid connectome states are sequenced shapes individuals' cognitive abilities and traits. Such sub-second connectome dynamics may inform about behavioral function and dysfunction and serve as endophenotypes for cognitive abilities.

Rapid dynamics of electrophysiological connectome states are heritable

Time-varying changes in whole-brain connectivity patterns, or connectome state dynamics, are a prominent feature of brain activity with broad functional implications. While infra-slow (<0.1Hz) connectome dynamics have been extensively studied with fMRI, rapid dynamics highly relevant for cognition are poorly understood. Here, we asked whether rapid electrophysiological connectome dynamics constitute subject-specific brain traits and to what extent they are under genetic influence. Using source-localized EEG connectomes during resting-state (N=928, 473 females), we quantified heritability of multivariate (multi-state) features describing temporal or spatial characteristics of connectome dynamics. States switched rapidly every ~60-500ms. Temporal features were heritable, particularly, Fractional Occupancy (in theta, alpha, beta, and gamma bands) and Transition Probability (in theta, alpha, and gamma bands), representing the duration spent in each state and the frequency of state switches, respectively. Genetic effects explained a substantial proportion of phenotypic variance of these features: Fractional Occupancy in beta (44.3%) and gamma (39.8%) bands and Transition Probability in theta (38.4%), alpha (63.3%), beta (22.6%), and gamma (40%) bands. However, we found no evidence for heritability of spatial features, specifically states' Modularity and connectivity pattern. We conclude that genetic effects strongly shape individuals' connectome dynamics at rapid timescales, specifically states' overall occurrence and sequencing.

Genome-wide association study meta-analysis of dizygotic twinning illuminates genetic regulation of female fecundity

STUDY QUESTION

Which genetic factors regulate female propensity for giving birth to spontaneous dizygotic (DZ) twins?

SUMMARY ANSWER

We identified four new loci, GNRH1, FSHR, ZFPM1, and IPO8, in addition to previously identified loci, FSHB and SMAD3.

WHAT IS KNOWN ALREADY

The propensity to give birth to DZ twins runs in families. Earlier, we reported that FSHB and SMAD3 as associated with DZ twinning and female fertility measures.

STUDY DESIGN, SIZE, DURATION

We conducted a genome-wide association meta-analysis (GWAMA) of mothers of spontaneous dizygotic (DZ) twins (8265 cases, 264 567 controls) and of independent DZ twin offspring (26 252 cases, 417 433 controls).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Over 700 000 mothers of DZ twins, twin individuals and singletons from large cohorts in Australia/New Zealand, Europe, and the USA were carefully screened to exclude twins born after use of ARTs. Genetic association analyses by cohort were followed by meta-analysis, phenome wide association studies (PheWAS), in silico and in vivo annotations, and Zebrafish functional validation.

MAIN RESULTS AND THE ROLE OF CHANCE

This study enlarges the sample size considerably from previous efforts, finding four genome-wide significant loci, including two novel signals and a further two novel genes that are implicated by gene level enrichment analyses. The novel loci, GNRH1 and FSHR, have well-established roles in female reproduction whereas ZFPM1 and IPO8 have not previously been implicated in female fertility. We found significant genetic correlations with multiple aspects of female reproduction and body size as well as evidence for significant selection against DZ twinning during human evolution. The 26 top single nucleotide polymorphisms (SNPs) from our GWAMA in European-origin participants weakly predicted the crude twinning rates in 47 non-European populations (r = 0.23 between risk score and population prevalence, s.e. 0.11, 1-tail P = 0.058) indicating that genome-wide association studies (GWAS) are needed in African and Asian populations to explore the causes of their respectively high and low DZ twinning rates. In vivo functional tests in zebrafish for IPO8 validated its essential role in female, but not male, fertility. In most regions, risk SNPs linked to known expression quantitative trait loci (eQTLs). Top SNPs were associated with in vivo reproductive hormone levels with the top pathways including hormone ligand binding receptors and the ovulation cycle.

LARGE SCALE DATA

The full DZT GWAS summary statistics will made available after publication through the GWAS catalog (https://www.ebi.ac.uk/gwas/).

LIMITATIONS, REASONS FOR CAUTION

Our study only included European ancestry cohorts. Inclusion of data from Africa (with the highest twining rate) and Asia (with the lowest rate) would illuminate further the biology of twinning and female fertility.

WIDER IMPLICATIONS OF THE FINDINGS

About one in 40 babies born in the world is a twin and there is much speculation on why twinning runs in families. We hope our results will inform investigations of ovarian response in new and existing ARTs and the causes of female infertility.

STUDY FUNDING/COMPETING INTEREST(S)

Support for the Netherlands Twin Register came from the Netherlands Organization for Scientific Research (NWO) and The Netherlands Organization for Health Research and Development (ZonMW) grants, 904-61-193, 480-04-004, 400-05-717, Addiction-31160008, 911-09-032, Biobanking and Biomolecular Resources Research Infrastructure (BBMRI.NL, 184.021.007), Royal Netherlands Academy of Science Professor Award (PAH/6635) to DIB, European Research Council (ERC-230374), Rutgers University Cell and DNA Repository (NIMH U24 MH068457-06), the Avera Institute, Sioux Falls, South Dakota (USA) and the National Institutes of Health (NIH R01 HD042157-01A1) and the Genetic Association Information Network (GAIN) of the Foundation for the National Institutes of Health and Grand Opportunity grants 1RC2 MH089951. The QIMR Berghofer Medical Research Institute (QIMR) study was supported by grants from the National Health and Medical Research Council (NHMRC) of Australia (241944, 339462, 389927, 389875, 389891, 389892, 389938, 443036, 442915, 442981, 496610, 496739, 552485, 552498, 1050208, 1075175). L.Y. is funded by Australian Research Council (Grant number DE200100425). The Minnesota Center for Twin and Family Research (MCTFR) was supported in part by USPHS Grants from the National Institute on Alcohol Abuse and Alcoholism (AA09367 and AA11886) and the National Institute on Drug Abuse (DA05147, DA13240, and DA024417). The Women's Genome Health Study (WGHS) was funded by the National Heart, Lung, and Blood Institute (HL043851 and HL080467) and the National Cancer Institute (CA047988 and UM1CA182913), with support for genotyping provided by Amgen. Data collection in the Finnish Twin Registry has been supported by the Wellcome Trust Sanger Institute, the Broad Institute, ENGAGE-European Network for Genetic and Genomic Epidemiology, FP7-HEALTH-F4-2007, grant agreement number 201413, National Institute of Alcohol Abuse and Alcoholism (grants AA-12502, AA-00145, AA-09203, AA15416, and K02AA018755) and the Academy of Finland (grants 100499, 205585, 118555, 141054, 264146, 308248, 312073 and 336823 to J. Kaprio). TwinsUK is funded by the Wellcome Trust, Medical Research Council, Versus Arthritis, European Union Horizon 2020, Chronic Disease Research Foundation (CDRF), Zoe Ltd and the National Institute for Health Research (NIHR) Clinical Research Network (CRN) and Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust in partnership with King's College London. For NESDA, funding was obtained from the Netherlands Organization for Scientific Research (Geestkracht program grant 10000-1002), the Center for Medical Systems Biology (CSMB, NVVO Genomics), Biobanking and Biomolecular Resources Research Infrastructure (BBMRI-NL), VU University's Institutes for Health and Care Research (EMGO+) and Neuroscience Campus Amsterdam, University Medical Center Groningen, Leiden University Medical Center, National Institutes of Health (NIH, ROI D0042157-01A, MH081802, Grand Opportunity grants 1 RC2 Ml-1089951 and IRC2 MH089995). Part of the genotyping and analyses were funded by the Genetic Association Information Network (GAIN) of the Foundation for the National Institutes of Health. Computing was supported by BiG Grid, the Dutch e-Science Grid, which is financially supported by NWO. Work in the Del Bene lab was supported by the Programme Investissements d'Avenir IHU FOReSIGHT (ANR-18-IAHU-01). C.R. was supported by an EU Horizon 2020 Marie Skłodowska-Curie Action fellowship (H2020-MSCA-IF-2014 #661527). H.S. and K.S. are employees of deCODE Genetics/Amgen. The other authors declare no competing financial interests.

TRIAL REGISTRATION NUMBER

N/A.

Mechanisms of cognitive disinhibition explain individual differences in adult attention deficit hyperactivity disorder traits

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) in adults is strongly associated with psychiatric comorbidity and functional impairment. Here, we aimed to use a newly developed online cognitive battery with strong psychometric properties for measuring individual differences in three cognitive mechanisms proposed to underlie ADHD traits in adults: 1) attentional control - the ability to mobilize cognitive resources to stop a prepotent motor response; 2) information sampling/gathering - adequate sampling of information in a stimulus detection task prior to making a decision; and 3) shifting - the ability to adapt behavior in response to positive and negative contingencies.

METHODS

This cross-sectional and correlational study recruited 650 adults (330 males) aged 18-69 years (M = 33.06; MD = 31.00; SD = 10.50), with previously diagnosed ADHD (n = 329) and those from the general community without a history of ADHD (n = 321). Self-report measures of ADHD traits (i.e., inattention/disorganization, impulsivity, hyperactivity) and the cognitive battery were completed online.

RESULTS

Latent class analysis, exploratory structural equation modeling and factor mixture modeling revealed self-reported ADHD traits formed a unidimensional and approximately normally distributed phenotype. Bayesian structural equation modeling demonstrated that all three mechanisms measured by the cognitive battery, explained unique, incremental variance in ADHD traits, with a total of 15.9% explained in the ADHD trait factor.

CONCLUSIONS

Attentional control and shifting, as well as the less researched cognitive process of information gathering, explain individual difference variance in self-reported ADHD traits with potential to yield genetic and neurobiological insights into adult ADHD.

Simultaneous selection of multiple important single nucleotide polymorphisms in familial genome wide association studies data

We propose a resampling-based fast variable selection technique for detecting relevant single nucleotide polymorphisms (SNP) in a multi-marker mixed effect model. Due to computational complexity, current practice primarily involves testing the effect of one SNP at a time, commonly termed as 'single SNP association analysis'. Joint modeling of genetic variants within a gene or pathway may have better power to detect associated genetic variants, especially the ones with weak effects. In this paper, we propose a computationally efficient model selection approach-based on the e-values framework-for single SNP detection in families while utilizing information on multiple SNPs simultaneously. To overcome computational bottleneck of traditional model selection methods, our method trains one single model, and utilizes a fast and scalable bootstrap procedure. We illustrate through numerical studies that our proposed method is more effective in detecting SNPs associated with a trait than either single-marker analysis using family data or model selection methods that ignore the familial dependency structure. Further, we perform gene-level analysis in Minnesota Center for Twin and Family Research (MCTFR) dataset using our method to detect several SNPs using this that have been implicated to be associated with alcohol consumption.

Personality and peer groups in adolescence: Reciprocal associations and shared genetic and environmental influences

OBJECTIVE

Peer groups represent a critical developmental context in adolescence, and there are many well-documented associations between personality and peer behavior at this age. However, the precise nature and direction of these associations are difficult to determine as youth both select into, and are influenced by, their peers.

METHOD

We thus examined the phenotypic, genetic, and environmental links between antisocial and prosocial peer characteristics and several personality traits from middle childhood to late adolescence (ages 11, 14, and 17 years) in a longitudinal twin sample (N = 3762) using teacher ratings of personality and self-reports of peer characteristics.

RESULTS

Less adaptive trait profiles (i.e., high negative emotionality, low conscientiousness, and low agreeableness) were associated with more antisocial and fewer prosocial peer characteristics across time. Associations between personality traits related to emotionality (negative emotionality and extraversion) and peer behavior were largely attributable to shared genetic influences, while associations between personality traits related to behavioral control (conscientiousness and agreeableness) and peer behavior were due to overlapping genetic and shared environmental influences.

CONCLUSIONS

Overall, results suggest a set of environmental presses that push youth toward both behavioral undercontrol and antisocial peer affiliations, making the identification of such influences and their relative importance a critical avenue of future work.

Childhood trauma predicts blunted error monitoring in adulthood: An event-related potential study

Abuse and neglect have detrimental consequences on emotional and cognitive functioning during childhood and adolescence, including error monitoring, which is a critical aspect of cognition that has been implicated in certain internalizing and externalizing psychopathologies. It is unclear, however, whether (a) childhood trauma has effects on error monitoring and, furthermore whether, (b) error monitoring mediates the relation between childhood trauma and psychopathology in adulthood. To this end, in a large sample of young adults (ages 18-30) who were oversampled for psychopathology (N = 390), the present study assessed relations between childhood trauma and error-related negativity (ERN), which is a widely used neurophysiological indicator of error monitoring. Cumulative childhood trauma predicted ERN blunting, as did two specific types of traumas: sexual abuse and emotional neglect. Furthermore, the ERN partially mediated the effects of cumulative childhood trauma and emotional neglect on externalizing-related symptoms. Future studies should further examine the relations between childhood trauma and error monitoring in adulthood, which can help to inform intervention approaches.

The Concept of Resistance to Substance Use and a Research Approach: The Resist! Project

Illicit substance use is dangerous in both acute and chronic forms, frequently resulting in lethal poisoning, addiction, and other negative consequences. Similar to research in other psychiatric conditions, whose ultimate goal is to enable effective prevention and treatment, studies in substance use are focused on factors elevating the risk for the disorder. The rapid growth of the substance use problem despite the effort invested in fighting it, however, suggests the need in changing the research approach. Instead of attempting to identify risk factors, whose neutralization is often infeasible if not impossible, it may be more promising to systematically reverse the perspective to the factors enhancing the aspect of liability to disorder that shares the same dimension but is opposite to risk, that is, resistance to substance use. Resistance factors, which enable the majority of the population to remain unaffected despite the ubiquity of psychoactive substances, may be more amenable to translation. While the resistance aspect of liability is symmetric to risk, the resistance approach requires substantial changes in sampling (high-resistance rather than high-risk) and using quantitative indices of liability. This article provides an overview and a practical approach to research in resistance to substance use/addiction, currently implemented in a NIH-funded project. The project benefits from unique opportunities afforded by the data originating from two longitudinal twin studies, the Virginia Twin Study of Adolescent and Behavioral Development and the Minnesota Twin Family Study. The methodology described is also applicable to other psychiatric disorders.

Longitudinal stability and change in time-frequency measures from an oddball task during adolescence and early adulthood

Time-frequency representations of electroencephalographic signals lend themselves to a granular analysis of cognitive and psychological processes. Characterizing developmental trajectories of time-frequency measures can thus inform us about the development of the processes involved as well as correlated traits and behaviors. We decomposed electroencephalographic (EEG) activity in a large sample of individuals (N = 1692; 917 females), assessed at approximately 3-year intervals from the age of 11 to their mid-20s. Participants completed an oddball task that elicits a robust P3 response. Principal component analysis served to identify the primary dimensions of time-frequency energy. Component loadings were virtually identical across assessment waves. A common and stable set of time-frequency dynamics thus characterized EEG activity throughout this age range. Trajectories of changes in component scores suggest that aspects of brain development reflected in these components comprise two distinct phases, with marked decreases in component amplitude throughout much of adolescence followed by smaller yet significant rates of decreases into early adulthood. Although the structure of time-frequency activity was stable throughout adolescence and early adulthood, we observed subtle change in component loadings as well. Our findings suggest that striking developmental change in event-related potentials emerges through a gradual change in the magnitude and timing of a stable set of dimensions of time-frequency activity, illustrating the usefulness of time-frequency representations of EEG signals and longitudinal designs for understanding brain development. In addition, we provide proof of concept that trajectories of time-frequency activity can serve as potential endophenotypes for childhood externalizing psychopathology and alcohol use in adolescence and early adulthood.

Construct Validity of Triarchic Model Traits in the Dunedin Multidisciplinary Health and Development Study Using the Multidimensional Personality Questionnaire

The triarchic model of psychopathy emphasizes the role of three phenotypic personality domains (boldness, meanness, and disinhibition) that have been operationalized using the well-established Multidimensional Personality Questionnaire. The present study sought to further validate the MPQ-Tri scales and examine their temporal stability and predictive validity across two time points (ages 18 and 26) from the Dunedin Multidisciplinary Health and Development Study, a population-representative and longitudinal sample (N = 1,037). This investigation necessitated modification of the MPQ-Tri scales to enable their use in a broader range of samples, including the Dunedin Study. The revised MPQ-Tri scales demonstrated good temporal stability, and correlation and multiple linear regression analyses predominantly revealed associations consistent with theoretical expectations. Overall, the findings provide support for the MPQ-Tri scales as reliable, stable, and valid measures of the triarchic constructs, which provide a unique opportunity to examine highly novel research questions concerning psychopathy in a wide variety of samples.

Threat-induced alterations in cognition and associations with dysregulated behavior

Previous literature suggests that threat disrupts cognitive control, especially for those prone to engaging in dysregulated behaviors (i.e., maladaptive attempts at regulating stress). However, this relationship is not well understood and has yet to be directly examined. The current study extends previous literature by examining the link between individual differences in dysregulation and threat-related alterations in neurocognitive and behavioral indicators of cognitive control. Using a diverse community sample (N = 143), we recorded participants' brain activity during a flanker task under conditions of predictable, unpredictable, and no threat-of-shock. Findings revealed a nuanced relationship, whereby predictable threat, relative to unpredictable threat, was associated with larger N2 to flankers, perhaps at the expense of a reduced later P3. We also found a relationship between proneness toward dysregulated behaviors and threat-induced alterations of cognitive control, with those higher in dysregulation showing reduced conflict P3 differentiation and accuracy interference during threat vs. no threat conditions. This research expands what is known about how threat can modulate cognition in everyday life and linked it to dysregulated behaviors with high societal burden.

Exploring the possibility of parents' broad internalizing phenotype acting through passive gene-environment correlations on daughters' disordered eating

Twin studies demonstrate significant environmental influences and a lack of genetic effects on disordered eating before puberty in girls. However, genetic factors could act indirectly through passive gene-environment correlations (rGE; correlations between parents' genes and an environment shaped by those genes) that inflate environmental (but not genetic) estimates. The only study to explore passive rGE did not find significant effects, but the full range of parental phenotypes (e.g., internalizing symptoms) that could impact daughters' disordered eating was not examined. We addressed this gap by exploring whether parents' internalizing symptoms (e.g., anxiety, depressive symptoms) contribute to daughters' eating pathology through passive rGE. Participants were female twin pairs (aged 8-14 years; M = 10.44) in pre-early puberty and their biological parents (n = 279 families) from the Michigan State University Twin Registry. Nuclear twin family models explored passive rGE for parents' internalizing traits/symptoms and twins' overall eating disorder symptoms. No evidence for passive rGE was found. Instead, environmental factors that create similarities between co-twins (but not with their parents) and unique environmental factors were important. In pre-early puberty, genetic factors do not influence daughters' disordered eating, even indirectly through passive rGE. Future research should explore sibling-specific and unique environmental factors during this critical developmental period.

The role of parenting in the intergenerational transmission of executive functioning: A genetically informed approach

Deficits in executive functioning both run in families and serve as a transdiagnostic risk factor for psychopathology. The present study employed twin modeling to examine parenting as an environmental pathway underlying the intergenerational transmission of executive functioning in an at-risk community sample of children and adolescents (N = 354 pairs, 167 monozygotic). Using structural equation modeling of multi-informant reports of parenting and a multi-method measure of child executive functioning, we found that better parent executive functioning related to less harsh, warmer parenting, which in turn related to better child executive functioning. Second, we assessed the etiology of executive functioning via the nuclear twin family model, finding large non-shared environmental effects (E = .69) and low-to-moderate heritability (A = .22). We did not find evidence of shared environmental effects or passive genotype-environment correlation. Third, a bivariate twin model revealed significant shared environmental overlap between both warm and harsh parenting and child executive functioning (which may indicate either passive genotype-environment correlation or environmental mediation), and non-shared environmental overlap between only harsh parenting and child executive functioning (indicating an effect of harsh parenting separable from genetic confounds). In summary, genetics contribute to the intergenerational transmission of executive functioning, with environmental mechanisms, including harsh parenting, also making unique contributions.

Parenting moderates the etiology of callous-unemotional traits in middle childhood

BACKGROUND

Callous-unemotional (CU) traits are associated with chronic and escalating trajectories of antisocial behavior. Extant etiologic studies suggest that heritability estimates for CU traits vary substantially, while also pointing to an environmental association between parenting and CU traits.

METHODS

We used twin modeling to estimate additive genetic (A), shared environmental (C), and nonshared environmental (E) influences on CU traits, measured with the Inventory of Callous-Unemotional Traits (ICU) and its subscales. Our sample included 600 twin pairs (age 6-11, 230 monozygotic) from neighborhoods with above-average levels of family poverty, a risk factor for antisocial behavior. We examined the extent to which correlations between parenting, measured via parent and child report on the Parental Environment Questionnaire, and CU traits reflected genetic versus environmental factors. Then, we tested whether parenting moderated the heritability of CU traits.

RESULTS

In the context of lower-income neighborhoods, CU traits were moderately to highly heritable (A = 54%) with similar moderate-to-high nonshared environmental influences (E = 46%). Bivariate models revealed that associations between CU traits and warm parenting were genetic (rA = .22) and environmental (rE = .19) in origin, whereas associations between CU traits and harsh parenting were largely genetic in origin (rA = .70). The heritability of CU traits decreased with increasing parental warmth and decreasing harshness.

CONCLUSIONS

Callous-unemotional traits are both genetic and environmental in origin during middle childhood, but genetic influences are moderated by parenting quality. Parenting may be an important target for interventions, particularly among youth with greater genetic risk.

The Relationship Between the Big Five Personality Factors, Anger-hostility, and Alcohol and Violence in Men and Women: A Nationally Representative Cohort of 15,701 Young Adults

Alcohol consumption is known to have a disinhibiting effect and is associated with a higher likelihood of aggressive behavior, especially among men. People with certain personality traits maybe more likely to behave aggressively when intoxicated, and there may also be variation by gender. We aimed to investigate whether the reason why men and women with certain personality traits are more likely to engage in violence may be because of their alcohol use.The Big Five personality traits and anger-hostility, alcohol consumption, and violence were measured by questionnaire in 15,701 nationally representative participants in the United States. We tested the extent to which alcohol mediates the relationship between personality factors and violence in men and women.We found that agreeableness was inversely associated with violence in both genders. Alcohol mediated approximately 11% of the effect in males, but there was no evidence of an effect in females. Anger-hostility was associated with violence in both sexes, but alcohol mediated the effect only in males. We also found that Extraversion was associated with violence and alcohol use in males and females. Alcohol accounted for 15% of the effect of extraversion on violence in males and 29% in females.The mechanism by which personality traits relate to violence may be different in men and women. Agreeableness and anger-hostility underpin the relationship between alcohol and violence in men, but not in women. Reducing alcohol consumption in men with disagreeable and angry/hostile traits would have a small but significant effect in reducing violence, whereas in women, reducing alcohol consumption among the extraverted, would have a greater effect.

Alcohol and nicotine polygenic scores are associated with the development of alcohol and nicotine use problems from adolescence to young adulthood

BACKGROUND AND AIMS

Molecular genetic studies of alcohol and nicotine use have identified many genome-wide association study (GWAS) loci. We measured associations between drinking and smoking polygenic scores (PGS) and trajectories of alcohol and nicotine use outcomes from late childhood to early adulthood, substance-specific versus broader-liability PGS effects, and if PGS performance varied for consumption versus problematic substance use.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

We fitted latent growth curve models with structured residuals to scores on measures of alcohol and nicotine use and problems from ages 14 to 34 years. We then estimated associations between the intercept (initial status) and slope (rate of change) parameters and PGSs for drinks per week (DPW), problematic alcohol use (PAU), cigarettes per day (CPD) and ever being a regular smoker (SMK), controlling for sex and genetic principal components. All data were analyzed in the United States. PGSs were calculated for participants of the Minnesota Twin Family Study (n = 3225) using results from the largest GWAS of alcohol and nicotine consumption and problematic use to date.

FINDINGS

Each PGS was associated with trajectories of use for their respective substances [i.e. DPW (βmean  = 0.08; βrange  = 0.02-0.12) and PAU (βmean  = 0.12; βrange  = -0.02 to 0.31) for alcohol; CPD (βmean  = 0.08; βrange  = 0.04-0.14) and SMK (βmean  = 0.18; βrange  = 0.05-0.36) for nicotine]. The PAU and SMK PGSs also exhibited cross-substance associations (i.e. PAU for nicotine-specific intercepts and SMK for alcohol intercepts and slope). All identified SMK PGS effects remained as significant predictors of nicotine and alcohol trajectories (βmean  = 0.15; βrange  = 0.02-0.33), even after adjusting for the respective effects of all other PGSs.

CONCLUSIONS

Substance use-related polygenic scores (PGSs) vary in the strength and generality versus specificity of their associations with substance use and problems over time. The regular smoking PGS appears to be a robust predictor of substance use trajectories and seems to measure both nicotine-specific and non-specific genetic liability for substance use, and potentially externalizing problems in general.

Multi-type childhood maltreatment exposure and substance use development from adolescence to early adulthood: A GxE study

BACKGROUND

Childhood maltreatment types can co-occur and are associated with increased substance use during adolescence and early adulthood. There is also a strong genetic basis for substance use which interacts with environmental factors (e.g., childhood maltreatment) to influence substance use phenotype.

OBJECTIVE

This research aimed to identify childhood maltreatment sub-groups based on type and chronicity, and their association with substance use change from adolescence to early adulthood, while accounting for the influence of substance use polygenic risk (i.e., genetic risk based on the combined effects of multiple genes).

PARTICIPANTS

We used a sample of unrelated European-origin Americans with genetic and childhood maltreatment data (n = 2,664) from the National Longitudinal Study of Adolescent to Adult Health.

METHODS

Latent profile analysis was used for sub-group identification and direct and interaction effects were tested for longitudinal trajectories of substance use utilizing generalized estimating equations.

RESULTS

Three sub-groups with co-occurring childhood maltreatment exposures were identified: a high sexual abuse sub-group, a high physical abuse sub-group, and a normative sub-group (with low maltreatment exposure). At high polygenic risk, the high physical abuse sub-group had faster increases in substance use over time. In comparison, the high sexual abuse sub-group had faster progression in substance use only at low and medium polygenic risk.

CONCLUSIONS

Findings provide initial evidence for biological and environmental differences among maltreatment sub-groups on trajectories of substance use.

Polygenic Score for Smoking is associated with Externalizing Psychopathology and Disinhibited Personality Traits but not Internalizing Psychopathology in Adolescence

We examined whether a polygenic score (PGS) for smoking measured genetic risk for general behavioral disinhibition by estimating its associations with externalizing and internalizing psychopathology and related personality traits at multiple time points in adolescence (ages 11, 14, and 17 years; N = 3225). The smoking PGS had strong associations with the stable variance across time for all the externalizing measures (mean standardized β = .27), agreeableness (β = -.22, 95% CI: -.28, -.16), and conscientiousness (β = -.19, 95% CI: -.24, -.13), but was not significantly associated with internalizing measures (mean β = .06) or extraversion (β = .01, 95% CI: -.05, .07). After controlling for smoking at age 17, the associations with externalizing, low agreeableness, and low conscientiousness remained statistically significant. The smoking PGS measures genetic influences that contribute to a spectrum of phenotypes related to behavioral disinhibition including externalizing psychopathology and normal-range personality traits related to behavioral control, but not internalizing psychopathology.

The clashing nature of rebelliousness: Nontraditional attitudes and counter-normative behaviors show divergent associations with intelligence

OBJECTIVE

Prior literature indicates that nontraditional attitudes are linked to higher intelligence. However, such attitudes in adolescence often accompany counter-normative, delinquent-type behaviors, which are themselves negatively linked with intelligence. This points to the possibility of suppression in the relationship between intelligence and nontraditional attitudes.

METHOD

We analyzed a large community sample of 17 year olds (N = 3330) with data on intelligence, nontraditional attitudes, and a diverse collection of self- and teacher-reported counter-normative behaviors. Developmental questions for these relationships were examined through cross-sectional comparisons between the adolescents and their parents as well as longitudinal analysis of the adolescent sample across emerging adulthood.

RESULTS

Youth who endorsed nontraditional attitudes had lower school grades, earlier age at first sex, heavier substance use, and were perceived as more oppositional by their teachers. Each of these problem behaviors was inversely related to intelligence. Accordingly, the positive correlation between nontraditional attitudes and intelligence was much weaker in adolescents as compared to their middle-aged parents. Longitudinal analyses revealed that the association between nontraditional attitudes and intelligence strengthens in early adulthood.

CONCLUSIONS

Associations between intelligence and sociopolitical attitudes can be obscured even by seemingly distal psychological characteristics.

Evaluating the validity of brief prototype-based informant ratings of triarchic psychopathy traits in prisoners

The validity of self-report psychopathy assessment has been questioned, especially in forensic settings where clinical evaluations influence critical decision-making (e.g., institutional placement, parole eligibility). Informant-based assessment offers a potentially valuable supplement to self-report but is challenging to acquire in under-resourced forensic contexts. The current study evaluated, within an incarcerated sample (n = 322), the extent to which brief prototype-based informant ratings of psychopathic traits as described by the triarchic model (boldness, meanness, disinhibition; Patrick et al., 2009) converge with self-report trait scores and show incremental validity in predicting criterion measures. Self/informant convergence was robust for traits of boldness and disinhibition, but weaker for meanness. Informant-rated traits showed incremental predictive validity over self-report traits, both within and across assessment domains. These findings indicate that simple prototype-based informant ratings of the triarchic traits can provide a useful supplement to self-report in assessing psychopathy within forensic-clinical settings.

The startle reflex as an indicator of psychopathic personality from childhood to adulthood: A systematic review

The startle reflex has been suggested to operate as a psychophysiological marker of psychopathic personality, based on findings from studies using a range of different methodologies and participant samples. The present review aims at synthesizing existing evidence of the relationship between psychopathy and the startle reflex across task paradigms, psychopathic personality subtypes and subdimensions, participant samples (i.e., incarcerated/ clinical or non-offenders), and age groups using the triarchic model of psychopathy as a frame of reference. Systematic literature searches were conducted up until the 24th of March 2020 in PubMed, PsycINFO, and Web of Science. A total of 2311 potential studies were identified, out of which 40 met relevancy and quality criteria. Results indicate that reduced aversive startle potentiation is associated with psychopathic personality in general, but clusters of traits relating to the triarchic model constructs of boldness and meanness in particular. Available evidence suggest that startle paradigms could be meaningful for differentiating individuals with and without psychopathic personality. Findings support suggestions of psychopathic personality as a multifaceted, rather than a unitary construct. Reduced aversive startle potentiation has also been found in relation to psychopathic features in child-aged samples but work of this kind is limited and more research is needed. Future studies should focus on greater consistency in task paradigms and analytic strategies to enhance the capacity to compare and integrate findings across studies.

Polygenic scores for smoking and educational attainment have independent influences on academic success and adjustment in adolescence and educational attainment in adulthood

Educational success is associated with greater quality of life and depends, in part, on heritable cognitive and non-cognitive traits. We used polygenic scores (PGS) for smoking and educational attainment to examine different genetic influences on facets of academic adjustment in adolescence and educational attainment in adulthood. PGSs were calculated for participants of the Minnesota Twin Family Study (N = 3225) and included as predictors of grades, academic motivation, and discipline problems at ages 11, 14, and 17 years-old, cigarettes per day from ages 14 to 24 years old, and educational attainment in adulthood (mean age 29.4 years). Smoking and educational attainment PGSs had significant incremental associations with each academic variable and cigarettes per day. About half of the adjusted effects of the smoking and education PGSs on educational attainment in adulthood were mediated by the academic variables in adolescence. Cigarettes per day from ages 14 to 24 years old did not account for the effect of the smoking PGS on educational attainment, suggesting the smoking PGS indexes genetic influences related to general behavioral disinhibition. In sum, distinct genetic influences measured by the smoking and educational attainment PGSs contribute to academic adjustment in adolescence and educational attainment in adulthood.

Co-development of alcohol use problems and antisocial peer affiliation from ages 11 to 34: selection, socialization and genetic and environmental influences

BACKGROUND AND AIMS

Social context is an important factor in determining the developmental trajectory of alcohol use. We examined the co-development between alcohol use problems and antisocial peer affiliation. We also estimated the genetic and environmental influences on alcohol use problems, antisocial peer affiliation and their co-development over time.

DESIGN

Longitudinal study using bivariate latent basis models with structured residuals (LBM-SR). A biometric model was then fitted to estimate the genetic and environmental influences on the growth factors and their covariances.

SETTING

The United States mid-west region.

PARTICIPANTS

Members of the Minnesota Twin Family Study (MTFS), an ongoing, longitudinal study of 3762 (52% female) twins (1881 pairs).

MEASUREMENTS

Alcohol use problems were assessed using a composite measure of average number of drinks per occasion in the past 12 months, maximum number of drinks in 24 hours and DSM-III-R symptoms of alcohol abuse and dependence. Antisocial peer affiliation was measured by self-report of the proportion of one's friends who exhibited types of antisocial behaviors.

FINDINGS

The LBM-SR model revealed that there was a large correlation between the growth factors for alcohol use problems and antisocial peer affiliation [r = 0.78, 95% confidence interval (CI) = 0.76, 0.80] and cross-lagged effects consistent with both selection and socialization effects. Additionally, antisocial peer affiliation in adolescence was associated with greater increases in alcohol use problems over time (r = 0.57, 95% CI = 0.54, 0.60). Genetic influences largely accounted for the association between antisocial peer affiliation in pre-adolescence and growth in alcohol use problems, while shared environmental influences accounted for the correlation between antisocial peer affiliation and alcohol use problems growth factors.

CONCLUSIONS

Antisocial peer affiliation in adolescence appears to be a salient, genetically influenced risk factor for early alcohol use and increase in alcohol use from adolescence to young adulthood.

Validity and utility of Hierarchical Taxonomy of Psychopathology (HiTOP): II. Externalizing superspectrum

The Hierarchical Taxonomy of Psychopathology (HiTOP) is an empirical effort to address limitations of traditional mental disorder diagnoses. These include arbitrary boundaries between disorder and normality, disorder co-occurrence in the modal case, heterogeneity of presentation within dis-orders, and instability of diagnosis within patients. This paper reviews the evidence on the validity and utility of the disinhibited externalizing and antagonistic externalizing spectra of HiTOP, which together constitute a broad externalizing superspectrum. These spectra are composed of elements subsumed within a variety of mental disorders described in recent DSM nosologies, including most notably substance use disorders and "Cluster B" personality disorders. The externalizing superspectrum ranges from normative levels of impulse control and self-assertion, to maladaptive disinhibition and antagonism, to extensive polysubstance involvement and personality psychopathology. A rich literature supports the validity of the externalizing superspectrum, and the disinhibited and antagonistic spectra. This evidence encompasses common genetic influences, environmental risk factors, childhood antecedents, cognitive abnormalities, neural alterations, and treatment response. The structure of these validators mirrors the structure of the phenotypic externalizing superspectrum, with some correlates more specific to disinhibited or antagonistic spectra, and others relevant to the entire externalizing superspectrum, underlining the hierarchical structure of the domain. Compared with traditional diagnostic categories, the externalizing superspectrum conceptualization shows improved utility, reliability, explanatory capacity, and clinical applicability. The externalizing superspectrum is one aspect of the general approach to psychopathology offered by HiTOP and can make diagnostic classification more useful in both research and the clinic.

Mechanisms of parent-child transmission of tobacco and alcohol use with polygenic risk scores: Evidence for a genetic nurture effect

Parent-child similarity is a function of genetic and environmental transmission. In addition, genetic effects not transmitted to offspring may drive parental behavior, thereby affecting the rearing environment of the child. Measuring genetic proclivity directly, through polygenic risk scores (PRSs), provides a way to test for the effect of nontransmitted parental genotype, on offspring outcome, termed a genetic nurture effect-in other words, if and how parental genomes might affect their children through the environment. The current study used polygenic risk scores for smoking initiation, cigarettes per day, and drinks per week to predict substance use in a sample of 3,008 twins, assessed prospectively from age 17-29, and their parents, from the Minnesota Center for Twin and Family Research. Mixed-effects models were used to test for a genetic nurture effect whereby parental PRSs predict offspring tobacco and alcohol use after statistically adjusting for offspring's own PRS. Parental smoking initiation PRS predicted offspring cigarettes per day at age 24 (β = .103, 95% CI [.03, .17]) and alcohol use at age 17 (β = .091, 95% CI [.04, .14]) independent of shared genetics. There was also a suggestive independent association between the parent PRS and offspring smoking at age 17 (β = .096; 95% CI [.02, .17]). Mediation analyses provided some evidence for environmental effects of parental smoking, alcohol use, and family socioeconomic status. These findings, and more broadly the molecular genetic method used, have implications on the identification of environmental effects on developmental outcomes such as substance use. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Multimodal indicators of risk for and consequences of substance use disorders: Executive functions and trait disconstraint assessed from preadolescence into early adulthood

Risk for substance use disorders (SUDs) is hypothesized to include behavioral disinhibition, a genetically mediated inability to inhibit or regulate behavior given task demands or motivational drives. In the present study, we examined developmental trajectories of multiple indicators of behavioral disinhibition assessed from preadolescence into early adulthood among individuals with versus without alcohol, tobacco, and cannabis use disorders. Participants were a population-based sample of 1512 male and female twins from the Minnesota Twin Family Study, prospectively assessed at ages 11, 14, 17, 20, and 24. Multimodal indicators of behavioral disinhibition included measures of executive function (visuospatial working memory accuracy, antisaccade task performance) and mother- and self-reported trait disconstraint. Multilevel modeling analyses that accounted for the repeated measures and nested nature of the twin family data were used to examine premorbid (age 11) indicators of executive function and trait disconstraint prior to the onset of any SUD symptoms, as well as changes from preadolescence into early adulthood (ages 11 to 24). Premorbid deviations evident at age 11 among individuals who subsequently developed SUDs included poorer performance on the visuospatial working memory test and higher levels of trait disconstraint. In addition, individuals with SUDs did not demonstrate developmentally normative improvements in inhibitory control (i.e., antisaccade performance did not improve) or in their levels of trait disconstraint. We conclude that these deviations in both neurocognitive and dispositional correlates of behavioral disinhibition precede onset of SUDs and may confer risk for their development, and in addition, problematic substance use may exacerbate preexisting deviations and interfere with normative developmental trajectories of executive function and trait disconstraint, with deleterious consequences for functioning.

Associations between adolescent cannabis use and young-adult functioning in three longitudinal twin studies

Observational studies have linked cannabis use to an array of negative outcomes, including psychiatric symptoms, cognitive impairment, and educational and occupational underachievement. These associations are particularly strong when cannabis use occurs in adolescence. Nevertheless, causality remains unclear. The purpose of the present study was thus to examine associations between prospectively assessed adolescent cannabis use and young-adult outcomes (psychiatric, cognitive, and socioeconomic) in three longitudinal studies of twins (n = 3,762). Twins reporting greater cumulative cannabis use in adolescence reported higher levels of psychopathology as well as poorer socioeconomic outcomes in young adulthood. However, cannabis use remained associated only with socioeconomic outcomes (i.e., educational attainment, occupational status, and income) in monozygotic-cotwin control analyses, which account fully for shared genetic and environmental confounding. Follow-up analyses examining associations between twin differences in adolescent cannabis use and longitudinal change in academic functioning during the middle- and high-school years provided a possible mechanism for these associations, indicating that greater cannabis use during this period was associated with decreases in grade point average and academic motivation as well as increases in academic problem behavior and school disciplinary problems. Our findings thus suggest that cannabis use in adolescence has potentially causal, deleterious effects on adolescent academic functioning and young-adult socioeconomic outcomes despite little evidence suggesting a strong, causal influence on adult mental health or cognitive ability.

Reprint of: Using a co-twin control design to evaluate alternative trait measures as indices of liability for substance use disorders

To establish a trait-dispositional variable as an indicator of liability for the development of substance use disorders (SUDs), the trait must share heritable variance with SUDs and its association should not be primarily attributable to a direct impact of SUDs on characteristics that define the trait. The current work applied a co-twin control (CTC) modeling approach to data from two monozygotic twin samples to investigate the degree to which different measures of trait-impulsiveness represent indicants of vulnerability to SUDs (liability indicators), or outcomes or concomitants of SUDs (exposure indicators). The Five Factor Model (FFM) trait of conscientiousness was assessed via self-report, and a counterpart neurobehavioral trait of disinhibition was assessed both through self-report and using self-report and brain response measures combined. FFM trait data were available for one twin sample (N = 298); data for variants of P3 brain response were available along with a scale measure of disinhibition in the other (N = 258). CTC analyses revealed only an exposure effect of SUD symptomatology on FFM conscientiousness, indicating that this self-report assessed trait does not index liability for SUDs. By contrast, the disinhibition scale measure showed pronounced liability and weaker exposure-based associations with SUDs - and when quantified using scale scores together with P3 brain response, the exposure-based association was eliminated, such that this disinhibition measure related to SUD symptoms exclusively as a function of liability influences. These findings highlight a distinct advantage of quantifying traits in neurobehavioral terms - namely, the capacity to effectively index dispositional liability for psychopathological outcomes.

Understanding the Progression from Early Alcohol Use Experimentation to Alcohol Use Disorder: Testing Vulnerability by Experience Interactions Using a Two-Part Latent Growth Curve Model

Most adolescents experiment with alcohol, but a smaller percentage advance to heavy alcohol use (AU) and AU disorder (AUD). Understanding for whom and how early risk leads to AUD is of interest to prevention, treatment, and etiology of AUD. Informed by developmental and behavioral neuroscience theory, the current study tested whether temperament (effortful control, surgency, and negative affect), peer AU (multi-reporter), and AU with parents' permission interacted to distinguish youth who experiment with alcohol from those who escalate to AUD. Community adolescents (N = 765, 53% female) were assessed annually for seven years (M_age = 11.8, range: 10-13 at Year 1; M_age = 18.7; range = 17-20 at year 7). Temperament by early experience interactions were expected to predict amount of AU. Amount of AU was expected to mediate the relationship between the interactions and AUD symptoms (assessed at Years 3 and 7, M_age = 13.8 and 18.7) above and beyond a range of confounds (e.g., problem behavior and parental AU and AUD). Supporting hypotheses, effortful control and surgency interacted with AU with parents' permission and peer AU, respectively, to predict higher amount of AU (R² = 0.47) and AUD symptoms (R² = 0.03). Results support developmental and behavioral neuroscience theory. High surgency and low effortful control in conjunction with peer AU and AU with parents' permission were associated with large effects on AU and moderate mediated effects through AU to AUD. AU with parents' permission was risky at low and high effortful control and protective when peers used alcohol.

Pursuing the developmental aims of the triarchic model of psychopathy: Creation and validation of triarchic scales for use in the USC: RFAB longitudinal twin project

The triarchic model was advanced as an integrative, trait-based framework for investigating psychopathy using different assessment methods and across developmental periods. Recent research has shown that the triarchic traits of boldness, meanness, and disinhibition can be operationalized effectively in youth, but longitudinal research is needed to realize the model's potential to advance developmental understanding of psychopathy. We report on the creation and validation of scale measures of the triarchic traits using questionnaire items available in the University of Southern California Risk Factors for Antisocial Behavior (RFAB) project, a large-scale longitudinal study of the development of antisocial behavior that includes measures from multiple modalities (self-report, informant rating, clinical-diagnostic, task-behavioral, physiological). Using a construct-rating and psychometric refinement approach, we developed triarchic scales that showed acceptable reliability, expected intercorrelations, and good temporal stability. The scales showed theory-consistent relations with external criteria including measures of psychopathy, internalizing/externalizing psychopathology, antisocial behavior, and substance use. Findings demonstrate the viability of measuring triarchic traits in the RFAB sample, extend the known nomological network of these traits into the developmental realm, and provide a foundation for follow-up studies examining the etiology of psychopathic traits and their relations with multimodal measures of cognitive-affective function and proneness to clinical problems.

Adolescent Sexual Development and Peer Groups: Reciprocal Associations and Shared Genetic and Environmental Influences

Peer groups influence the emergence of sexual behaviors in adolescence, but many details regarding the mechanisms underlying these effects have yet to be described. We examined the phenotypic, genetic, and environmental links between both antisocial and prosocial peer characteristics, and several sexual behaviors from middle childhood to late adolescence (ages 11, 14, and 17 years) using a longitudinal twin sample (N = 3762). Antisocial peers predicted greater engagement in both normative (e.g., dating) and non-normative (e.g., early sexual intercourse) sexual behaviors, while prosocial peers were associated with a lower likelihood of engaging in non-normative sexual behaviors. Reciprocal effects were also observed such that early sexual experiences were associated with a more antisocial and less prosocial peer groups later in adolescence. Behavioral genetic models indicated that most of the overlap between peer group characteristics and sexual behavior was due to shared environmental influences. That is, some features of the adolescent environment exert a press toward (or against) antisocial peers and sexual behaviors. Together, the results extend the existing literature by highlighting the ways through which peer affiliations are related to sexual development in adolescence.

Moderating Effects of Personality on the Genetic and Environmental Influences of School Grades Helps to Explain Sex Differences in Scholastic Achievement

Girls consistently achieve higher grades than boys despite scoring lower on major standardized tests and not having higher IQs. Sex differences in non-cognitive variables such as personality might help to account for sex differences in grades. Utilizing a large sample of 17 year-old twins participating in the Minnesota Twin Family Study (MTFS), we examined the roles of Achievement Striving, Self-Control, and Aggression on sex differences in grade point average (GPA). Each personality trait was a significant predictor of GPA, with sex differences in Aggression accounting for one-half the sex difference in GPA and genetic variance accounting for most of the overlap between personality and GPA. Achievement Striving and Self-Control moderated the genetic and environmental influences on GPA. Specifically, for girls but not boys, higher Achievement Striving and Self-Control were associated with less variability in GPA and greater genetic and environmental overlap with GPA. For girls, certain personality traits operate to shape a context yielding uniformly higher GPA, a process that seems absent in boys.

Toward a multimodal measurement model for the neurobehavioral trait of affiliative capacity

A growing body of research supports the value of a multimodal assessment approach, drawing on measures from different response modalities, for clarifying how core biobehavioral processes relate to various clinical problems and dimensions of psychopathology. Using data for 507 healthy adults, the current study was undertaken to integrate self-report and neurophysiological (brain potential) measures as a step toward a multimodal measurement model for the trait of affiliative capacity (AFF) - a biobehavioral construct relevant to adaptive and maladaptive social-interpersonal functioning. Individuals low in AFF exhibit a lack of interpersonal connectedness, deficient empathy, and an exploitative-aggressive social style that may be expressed transdiagnostically in antagonistic externalizing or distress psychopathology. Specific aims were to (1) integrate trait scale and brain potential indicators into a multimodal measure of AFF and (2) evaluate associations of this multimodal measure with criterion variables of different types. Results demonstrated (1) success in creating a multimodal measure of AFF from self-report and neural indicators, (2) effectiveness of this measure in predicting both clinical-diagnostic and neurophysiological criterion variables, and (3) transdiagnostic utility of the multimodal measure at both specific-disorder and broad symptom-dimension levels. Our findings further illustrate the value of psychoneurometric operationalizations of biobehavioral trait dimensions as referents for clarifying transdiagnostic relationships between biological systems variables and empirically defined dimensions of psychopathology.

The difference between trait disinhibition and impulsivity-and why it matters for clinical psychological science

In the psychological science field, there is substantial interest in quantifying individual differences in self-regulatory capacity because of its transdiagnostic relevance to various forms of psychopathology. Trait disinhibition and impulsiveness are popular conceptualizations of dispositions reflecting self-regulation of behavioral and emotional responding. In the literature, these constructs are often treated interchangeably because of their shared focus on general disconstraint and a lack of direct comparisons between measures of each. The current work used structural modeling to examine conceptual and empirical differences between 2 popular operationalizations of these traits in 2 samples (Ns = 400, 308), and employed regression and dominance analyses to compare their predictive relations with criterion measures of externalizing problems and negative affectivity (NA). Impulsigenic traits were related both to externalizing problems and NA, whereas trait disinhibition was selectively associated with externalizing. In a dominance analysis, trait disinhibition exhibited complete dominance over all impulsigenic traits in predicting externalizing problems. Conversely, multiple impulsigenic traits evidenced complete dominance over trait disinhibition in prediction of NA. The current work provides evidence that (a) disinhibition and impulsigenic traits are not interchangeable, (b) disinhibition specifically indexes propensity for externalizing problems, and (c) impulsigenic traits reflect a blend of externalizing and NA that appears relevant to diverse forms of psychopathology. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Derivation and assessment of the opioid use disorder severity scale: prediction of health, psychological and social adjustment problems

Background: Severity of substance use disorder (SUD) is typically evaluated by tabulating the number of symptoms. The resulting estimate of disorder severity is, however, biased due to intercorrelations among symptoms and their unequal salience. Objective. Employing item response theory (IRT) methodology, opioid use disorder symptoms were calibrated to derive the Opioid Use Disorder Severity Scale (OUDSS) and assess its predictive ability in men and women separately. Methods: A two-parameter IRT model was utilized to derive the OUDSS from DSM-IV symptoms recorded on the Structured Clinical Interview for DSM-IV (SCID) in 438 men and 429 women who reported at least one lifetime opioid consumption event. The predictive ability of the OUDSS was evaluated using the 10 health, psychological, and social adjustment domains of the revised Drug Use Screening Inventory (DUSI-R) assessed 2 years later. Results: The OUDSS score predicted the severity of problems in all 10 DUSI-R domains in men and women. The OUDSS also predicted the DUSI-R diagnostic cutoff score of overall problem density score in men and women (OR = 2.21 and OR = 4.83, respectively). Withdrawal was the most frequently endorsed symptom in this sample of opioid users. The other symptoms' frequencies, while somewhat lower than withdrawal's, did not differ from it substantially, indicating a similar severity threshold. Conclusions: OUDSS enables dimensional measurement of opioid use severity on an interval scale. The OUDSS and DUSI-R together can identify problem areas requiring prevention or treatment.

A nonparametric Bayesian model for estimating spectral densities of resting-state EEG twin data

Electroencephalography (EEG) is a noninvasive neuroimaging modality that captures electrical brain activity many times per second. We seek to estimate power spectra from EEG data that ware gathered for 557 adolescent twin pairs through the Minnesota Twin Family Study (MTFS). Typically, spectral analysis methods treat time series from each subject separately, and independent spectral densities are fit to each time series. Since the EEG data were collected on twins, it is reasonable to assume that the time series have similar underlying characteristics, so borrowing information across subjects can significantly improve estimation. We propose a Nested Bernstein Dirichlet prior model to estimate the power spectrum of the EEG signal for each subject by smoothing periodograms within and across subjects while requiring minimal user input to tuning parameters. Furthermore, we leverage the MTFS twin study design to estimate the heritability of EEG power spectra with the hopes of establishing new endophenotypes. Through simulation studies designed to mimic the MTFS, we show our method out-performs a set of other popular methods.

A Model-Based Strategy for Interfacing Traits of the DSM-5 AMPD With Neurobiology

The DSM-5 alternative model for personality disorders (AMPD) groups traits into domains based on factor analyses of self-report data. AMPD traits may need to be configured differently to interface with neurobiology. Focusing on biobehavioral risk for externalizing problems in 334 adults, the authors used structural modeling to evaluate how well alternative configurations of AMPD traits, operationalized using the Personality Inventory for DSM-5 (PID-5), interface with neural indicators of externalizing liability. A model specifying two correlated factors defined by traits within the PID-5 Disinhibition domain and brain-response indicators of externalizing proneness exhibited inadequate fit. However, a model using PID-5 traits with better coverage of biobehavioral externalizing liability evidenced good fit. Scores on this PID-5 trait factor, termed "PID-5 Externalizing Proneness," converged well with criterion measures of externalizing proneness and diverged from measures of threat sensitivity. Findings illustrate how AMPD traits can be configured for use in investigations of biobehavioral risk for psychopathology.

Heritability of overlapping impulsivity and compulsivity dimensional phenotypes

Impulsivity and compulsivity are traits relevant to a range of mental health problems and have traditionally been conceptualised as distinct constructs. Here, we reconceptualised impulsivity and compulsivity as partially overlapping phenotypes using a bifactor modelling approach and estimated heritability for their shared and unique phenotypic variance within a classical twin design. Adult twin pairs (N = 173) completed self-report questionnaires measuring psychological processes related to impulsivity and compulsivity. We fitted variance components models to three uncorrelated phenotypic dimensions: a general impulsive-compulsive dimension; and two narrower phenotypes related to impulsivity and obsessiveness.There was evidence of moderate heritability for impulsivity (A² = 0.33), modest additive genetic or common environmental effects for obsessiveness (A² = 0.25; C² = 0.23), and moderate effects of common environment (C² = 0.36) for the general dimension, This general impulsive-compulsive phenotype may reflect a quantitative liability to related mental health disorders that indexes exposure to potentially modifiable environmental risk factors.

Personality, romantic relationships, and alcohol use disorder symptoms in adolescence and young adulthood: An evaluation of personality × social context interplay

Prior research has shown that person-level characteristics (e.g., temperament, personality) correlate and interact with social-contextual factors (e.g., parent-child relationship quality, antisocial peer affiliation) to predict adolescent substance use, but less research has examined similar processes for adult substance use problems. We addressed this gap by testing for personality × romantic partner context interplay in relation to symptoms of alcohol use disorder (AUD) at ages 24 and 29. Participants were twins in the longitudinal Minnesota Twin Family Study (N = 2,769; 52% female). Results support the corresponsive principle of personality in that we found that key personality traits in late adolescence (low constraint, negative emotionality) predicted subsequent "selection" into key social contexts in early adulthood (poorer quality romantic relationships and greater romantic partner alcohol use), which subsequently reinforced those traits and associated outcomes (including correlated AUD symptoms) through late young adulthood. There were few meaningful gender differences in these associations. There was also no support for the personality × romantic partner context interaction as a significant predictor of AUD symptoms at ages 24 or 29. Taken together with prior studies, these results suggest that such interactions may be less relevant to the development of young adult AUD compared to adolescent substance use problems.

Sexual Development in Adolescence: An Examination of Genetic and Environmental Influences

Sexual development entails many experiences and is a major feature of adolescence. Most relevant behavioral genetic studies, however, focus primarily on sexual behaviors associated with health risks. We took a more normative, developmental perspective by examining genetic and environmental influences on five sexual behaviors ranging from dating to pregnancy in middle (M_age  = 14.90 years) and late adolescence (M_age  = 17.85 years) in a sample of twins (N = 3,762). Overall, behaviors that are more common and socially sanctioned (e.g., dating) were more heritable than behaviors that are less common and socially acceptable (e.g., sexual intercourse). That the etiology of different sexual behaviors is tied to their normativeness highlights the importance of considering the broader developmental context when studying sexual development.

Familial factors and the risk of borderline personality pathology: genetic and environmental transmission

BACKGROUND

Parental characteristics and practices predict borderline personality disorder (BPD) symptoms in children. However, it is difficult to disentangle whether these effects are genetically or environmentally mediated. The present study examines the contributions of genetic and environmental influences by comparing the effects of familial risk factors (i.e. parental psychopathology and borderline traits, maladaptive parenting, marital discord) on child BPD traits in genetically related (biological) and non-related (adoptive) families.

METHODS

Data are from 409 adoptive and 208 biological families who participated in the Siblings Interaction and Behavior Study (SIBS) and 580 twin families the Minnesota Twin Family Study (MTFS). Parent characteristics and practices included parental psychopathology (measured via structured clinical interviews), parental BPD traits, parenting behaviors, and marital discord. A series of multi-level regression models were estimated to examine the relationship of familial risk factors to child BPD traits and to test whether children's adoptive status moderated the association.

RESULTS

Symptom counts of parents' conduct disorder, adult antisocial behavior, nicotine, alcohol, and illicit drug dependence, and paternal BPD traits substantially predicted child BPD traits only in biological offspring, implying genetic transmission. Maternal BPD traits and both maternal and paternal conflict, lack of regard, and lack of involvement predicted offspring BPD traits regardless of the adoptive status, implying environmental transmission.

CONCLUSIONS

Parental externalizing psychopathology and father's BPD traits contribute genetic risk for offspring BPD traits, but mothers' BPD traits and parents' poor parenting constitute environmental risks for the development of these offspring traits.

Adolescent Externalizing Psychopathology and Its Prospective Relationship to Marijuana Use Development from Age 14 to 30: Replication Across Independent Longitudinal Twin Samples

Externalizing psychopathology in early adolescence is a highly heritable risk factor for drug use, yet how it relates to marijuana use development is not well-characterized. We evaluate this issue in independent twin samples from Colorado (N = 2608) and Minnesota (N = 3630), assessed from adolescence to early adulthood. We used a biometric latent growth model of marijuana use frequency with data from up to five waves of assessment from ages 14 to 30, to examine change in marijuana use and its relationship with a factor model of adolescent externalizing psychopathology. The factor structure of adolescent externalizing psychopathology was similar across samples, as was the association between that common factor and early marijuana use (Minnesota r = 0.67 [0.60, 0.75]; Colorado r = 0.69 [0.59, 0.78]), and increase in use (Minnesota r = 0.18 [0.10, 0.26]; Colorado r = 0.20 [0.07, 0.34]). Early use was moderately heritable in both samples (Minnesota h² = 0.57 [0.37, 0.79]; Colorado h² = 0.42 [0.14, 0.73]). Increase in use was highly heritable in Minnesota (h² = 0.82 [0.72, 0.88]), less so in Colorado (h² = 0.22 [0.01, 0.66]), and shared environmental effects were larger in Colorado (c² = 0.55 [0.14, 0.83]) than Minnesota (c² = 0 [0, 0.06]). We found moderate genetic correlations between externalizing psychopathology and early use in both samples. Finally, additional analyses in the Minnesota sample indicated that marijuana use decreased during the late 20s. This decline is strongly heritable (h² = 0.73 [0.49, 0.91]) and moderately negatively correlated with adolescent externalizing psychopathology (r = - 0.41 [- 0.54, - 0.28]). Adolescent externalizing psychopathology is genetically correlated with change in late adolescent marijuana use (late teens, early 20s), as well as maintenance of use in early adulthood (late 20 s) even after controlling for the effects of early use.

Using a co-twin control design to evaluate alternative trait measures as indices of liability for substance use disorders

To establish a trait-dispositional variable as an indicator of liability for the development of substance use disorders (SUDs), the trait must share heritable variance with SUDs and its association should not be primarily attributable to a direct impact of SUDs on characteristics that define the trait. The current work applied a co-twin control (CTC) modeling approach to data from two monozygotic twin samples to investigate the degree to which different measures of trait-impulsiveness represent indicants of vulnerability to SUDs (liability indicators), or outcomes or concomitants of SUDs (exposure indicators). The Five Factor Model (FFM) trait of conscientiousness was assessed via self-report, and a counterpart neurobehavioral trait of disinhibition was assessed both through self-report and using self-report and brain response measures combined. FFM trait data were available for one twin sample (N = 298); data for variants of P3 brain response were available along with a scale measure of disinhibition in the other (N = 258). CTC analyses revealed only an exposure effect of SUD symptomatology on FFM conscientiousness, indicating that this self-report assessed trait does not index liability for SUDs. By contrast, the disinhibition scale measure showed pronounced liability and weaker exposure-based associations with SUDs - and when quantified using scale scores together with P3 brain response, the exposure-based association was eliminated, such that this disinhibition measure related to SUD symptoms exclusively as a function of liability influences. These findings highlight a distinct advantage of quantifying traits in neurobehavioral terms - namely, the capacity to effectively index dispositional liability for psychopathological outcomes.

Analysis of substance use and its outcomes by machine learning I. Childhood evaluation of liability to substance use disorder

BACKGROUND

Substance use disorder (SUD) exacts enormous societal costs in the United States, and it is important to detect high-risk youths for prevention. Machine learning (ML) is the method to find patterns and make prediction from data. We hypothesized that ML identifies the health, psychological, psychiatric, and contextual features to predict SUD, and the identified features predict high-risk individuals to develop SUD.

METHOD

Male (N = 494) and female (N = 206) participants and their informant parents were administered a battery of questionnaires across five waves of assessment conducted at 10-12, 12-14, 16, 19, and 22 years of age. Characteristics most strongly associated with SUD were identified using the random forest (RF)algorithm from approximately 1000 variables measured at each assessment. Next, the complement of features was validated, and the best models were selected for predicting SUD using seven ML algorithms. Lastly, area under the receiver operating characteristic curve (AUROC) evaluated accuracy of detecting individuals who develop SUD+/- up to thirty years of age.

RESULTS

Approximately thirty variables strongly predict SUD. The predictors shift from psychological dysregulation and poor health behavior in late childhood to non-normative socialization in mid to late adolescence. In 10-12-year-old youths, the features predict SUD+/- with 74% accuracy, increasing to 86% at 22 years of age. The RF algorithm optimally detects individuals between 10-22 years of age who develop SUD compared to other ML algorithms.

CONCLUSION

These findings inform the items required for inclusion in instruments to accurately identify high risk youths and young adults requiring SUD prevention.