Early adolescent aggression predicts antisocial personality disorder in young adults: a population-based study

Association between trajectories of the neighborhood social exposome and mental health in late adolescence: A FinnTwin12 cohort study

BACKGROUND

Adolescent mental health problems impose a significant burden. Exploring evolving social environments could enhance comprehension of their impact on mental health. We aimed to depict the trajectories of the neighborhood social exposome from middle to late adolescence and assess the intricate relationship between them and late adolescent mental health.

METHODS

Participants (n = 3965) from the FinnTwin12 cohort with completed questionnaires at age 17 were used. Nine mental health measures were assessed. The social exposome comprised 28 neighborhood social indicators. Trajectories of these indicators from ages 12 to 17 were summarized via latent growth curve modeling into growth factors, including baseline intercept. Mixture effects of all growth factors were assessed through quantile-based g-computation. Repeated generalized linear regressions identified significant growth factors. Sex stratification was performed.

RESULTS

The linear-quadratic model was the most optimal trajectory model. No mixture effect was detected. Regression models showed some growth factors saliently linked to the p-factor, internalizing problems, anxiety, hyperactivity, and aggression. The majority of them were baseline intercepts. Quadratic growth factors about mother tongues correlated with anxiety among sex-combined participants and males. The linear growth factor in the proportion of households of couples without children was associated with internalizing problems in females.

LIMITATIONS

We were limited to including only neighborhood-level social exposures, and the multilevel contextual exposome situation interfered with our assessment.

CONCLUSIONS

Trajectories of the social neighborhood exposome modestly influenced late adolescent mental health. Tackling root causes of social inequalities through targeted programs for living conditions could improve adolescent mental health.

Proteomic insights into mental health status: plasma markers in young adults

Global emphasis on enhancing prevention and treatment strategies necessitates an increased understanding of the biological mechanisms of psychopathology. Plasma proteomics is a powerful tool that has been applied in the context of specific mental disorders for biomarker identification. The p-factor, also known as the "general psychopathology factor", is a concept in psychopathology suggesting that there is a common underlying factor that contributes to the development of various forms of mental disorders. It has been proposed that the p-factor can be used to understand the overall mental health status of an individual. Here, we aimed to discover plasma proteins associated with the p-factor in 775 young adults in the FinnTwin12 cohort. Using liquid chromatography-tandem mass spectrometry, 13 proteins with a significant connection with the p-factor were identified, 8 of which were linked to epidermal growth factor receptor (EGFR) signaling. This exploratory study provides new insight into biological alterations associated with mental health status in young adults.

Intervention format and therapist-child agreement associated with therapeutic alliance and outcomes

OBJECTIVE

The study examined the effects of therapeutic alliance (TA; relational bond, task collaboration) on externalizing behavior outcomes, how TA can operate differently when children are seen in individual versus group sessions, and how therapist-child disagreement in perceptions of TA affects outcomes.

METHOD

Three hundred sixty children (Ages 9.2-11.8; 65% male; 78.1% Black) identified as having high rates of aggressive behavior by the fourth-grade teachers, and their 20 elementary schools were randomized to group versus individual delivery of the cognitive behavioral intervention, Coping Power. TA ratings were collected from children and therapists at mid and end of intervention using the Therapeutic Alliance Scale for Children. Teacher ratings of children's externalizing and internalizing behavior problems were collected prior to intervention and at 1-year follow-up after intervention using the Behavior Assessment System for Children.

RESULTS

Children receiving the intervention individually reported significantly higher trait-like levels of task collaboration than did children seen in groups. Independent of intervention format, higher trait-like levels of therapist-rated bond and task collaboration predicted reduced levels of externalizing problems, and higher trait-like levels of child- and therapist-rated task-collaboration and therapist-rated bond predicted reduced levels of internalizing problems. Differences between therapist and child reports of bond predicted weaker reductions in internalizing behavior for children seen in groups.

CONCLUSIONS

It is essential to train therapists to develop and assess for TA by midintervention with children with aggressive behavior problems, especially if they are seen in small groups, and to determine if therapists may misperceive the strength of TA. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Psychosocial factors as predictors of aggressive behaviors among primary school learners

The study investigated psychosocial factors as predictors of aggressive behaviors among primary school learners in Ekiti State, Nigeria. The study used a survey research design. All public primary school learners in Ekiti State formed the target population. A sample size of one thousand three hundred and fifty (1350) respondents was selected using a multistage sampling procedure, consisting of 641 males (47.5%) and 709 females (52.5%), ages 9-13 years, who participated in the study. A self-report instrument tagged "Learners' Aggressive Behaviours Questionnaire" (α indexes of .81, .70, .77, and .84 for the four components respectively) was used for data collection. The data were analyzed using multiple regression analysis at a 5% level of significance. The empirical findings revealed that parenting styles, peer influence, and self-control significantly predicted learners' aggressive behavior. Recommendations for curbing aggressive behavior among learners were highlighted.

Association of greenness surrounding school with aggression among adolescents: A multi-site study in China

Association of greenness surrounding school with aggression among adolescents was not well understood. This study aimed to investigate the associations of greenness surrounding school with adolescents' total and sub-types of aggression and explore potential mediators underlying these associations. A multi-site study of 15,301 adolescents aged 11-20 years were recruited through a multistage, random cluster sampling across 5 representative provinces in mainland China. Satellite-derived Normalized Difference Vegetation Index (NDVI) values within circular buffers of 100 m, 500 m, and 1000 m surrounding school were used to indicate the adolescents' greenness exposure. We used the Chinese version of Buss and Warren's Aggression Questionnaire to assess total and sub-types of aggression. Daily concentrations of PM2.5, and NO2 were obtained from the China High Air Pollutants datasets. Per IQR increment of NDVI 100 m and 500 m surrounding school was associated with lower odds of total aggression; odds ratio [OR] with 95% CI was 0.958 (0.926-0.990) for the 100 m buffer and 0.963 (0.932-0.996) for the 500 m buffer, respectively. Similar associations can be observed in two sub-types of aggression, including verbal (NDVI 100 m: 0.960 (0.925-0.995); NDVI500m: 0.964 (0.930-0.999)) and indirect aggression (NDVI 100 m: 0.956 (0.924-0.990); NDVI500m: 0.953 (0.921-0.986)). There were no sex and age differences in the associations of school surrounding greenness with aggression, except that the beneficial associations of greenness exposure with total aggression (0.933(0.895-0.975) vs.1.005(0.956-1.056)), physical aggression (0.971(0.925-1.019) vs.1.098(1.043-1.156)), and hostility (0.942(0.901-0.986) vs.1.016(0.965-1.069)) were greater among participants aged ≥16 years than those aged<16 years. PM2.5 (proportion mediated estimates: 0.21; 95% CI: 0.08, 0.94) and NO2 (-0.78, 95% CI: -3.22, -0.37) mediated the association of NDVI 500 m surrounding school with total aggression. Our data indicated that exposure to greenness in school surroundings was associated with reduced aggression, particularly in verbal and indirect aggression. The presence of PM2.5 and NO2 partially mediated these associations.

Psychiatric and non-psychiatric population vulnerabilities in time of a crisis: the unsuspected aggression factor

OBJECTIVES

In March 2020, France faced a health crisis due to the COVID-19 outbreak that, like previous infectious disease crises, involved high psychological and emotional stress, a series of factors that influenced the ongoing mental health crisis.

METHODS

We recruited 384 respondents to complete an online questionnaire during the second month of isolation: 176 psychotherapy recipients (68 were currently attending psychiatric care) and 208 healthy controls. We measured demographic characteristics, impulsivity, aggression, hopelessness, suicidal risk, and the global level of anxiety and depression in order to estimate potential discrepancies in clinical measures across these populations.

RESULTS

Our results indicate that the group currently undergoing psychiatric care was prone to loneliness and social isolation. Regarding clinical and nonclinical population, there were differences in suicidal risk, depression, anxiety, and hopelessness but mainly in aggression. Regression analysis also demonstrated that aggression surprisingly influenced anxiety levels. Patients undergoing therapy compared with patients who were not displayed differences only in suicidal risk, anxiety, and hopelessness, with those undergoing therapy having higher scores. The outpatient group undergoing therapy had a significantly lower level of impulsivity. Moreover, the regression to predict anxiety and depression levels from correlated factors highlighted the potentially heightened role of aggression in predicting anxiety in the clinical group.

CONCLUSION

New research into stress reactions should assess other clinical signals, such as aggression, and examine preventive mental health interventions in times of crisis.

Elevated levels of serotonin 5-HT2A receptors in the orbitofrontal cortex of antisocial individuals

Antisocial behavior (ASB) is characterized by frequent violations of the rights and properties of others, as well as aggressive conduct. While ample evidence points to a critical role of serotonin in the emotional modulation of social responses, the implication of this neurotransmitter in ASB is unclear. Here, we performed the first-ever postmortem analysis of serotonergic markers in the orbitofrontal cortex (OFC) of male subjects with ASB (n = 9). We focused on this brain region, given its well-recognized role in social response and ASB pathophysiology. Given that all individuals also had a substance use disorder (SUD) diagnosis, two age-matched control groups were used: SUD only and unaffected controls. Tissues were processed for immunoblotting analyses on eight key serotonergic targets: tryptophan hydroxylase 2 (TPH2), the rate-limiting enzyme of brain serotonin synthesis; serotonin transporter (SERT), the primary carrier for serotonin uptake; monoamine oxidase A (MAOA), the primary enzyme for serotonin catabolism; and five serotonin receptors previously shown to influence social behavior: 5-HT1A, 5-HT1B, 5-HT2A, 5-HT2C, and 5-HT4. Our analyses documented a significant increase in 5-HT2A receptor levels in the ASB + SUD group compared to SUD-only controls. Furthermore, TPH2 levels were significantly reduced in the SUD group (including SUD only and ASB + SUD) compared to unaffected controls. No difference was detected in the expression of any other serotonergic target. These results are in keeping with previous evidence showing high 5-HT2A receptor binding in the OFC of pathologically aggressive individuals and point to this molecule as a potential target for ASB treatment.

Integrative Multi-omics Analysis of Childhood Aggressive Behavior

This study introduces and illustrates the potential of an integrated multi-omics approach in investigating the underlying biology of complex traits such as childhood aggressive behavior. In 645 twins (cases = 42%), we trained single- and integrative multi-omics models to identify biomarkers for subclinical aggression and investigated the connections among these biomarkers. Our data comprised transmitted and two non-transmitted polygenic scores (PGSs) for 15 traits, 78,772 CpGs, and 90 metabolites. The single-omics models selected 31 PGSs, 1614 CpGs, and 90 metabolites, and the multi-omics model comprised 44 PGSs, 746 CpGs, and 90 metabolites. The predictive accuracy for these models in the test (N = 277, cases = 42%) and independent clinical data (N = 142, cases = 45%) ranged from 43 to 57%. We observed strong connections between DNA methylation, amino acids, and parental non-transmitted PGSs for ADHD, Autism Spectrum Disorder, intelligence, smoking initiation, and self-reported health. Aggression-related omics traits link to known and novel risk factors, including inflammation, carcinogens, and smoking.

The influence of NOS1AP gene polymorphisms and childhood abuse on antisocial personality disorder in Chinese male violent inmates

Antisocial personality disorder (ASPD) is a common behavioral pattern that causes sufferers to ignore or violate the rights of others. Though its cause is still unclear, previous studies have shown that childhood maltreatment is closely related to ASPD. The NOS1AP gene is associated with various neuropsychiatric diseases, but a linkage between it and ASPD has not yet been discovered. This study recruited ASPD and non-ASPD male subjects who had committed violent crimes from a prison in Nanjing, China. By comparing the two groups' genotypes, allele frequencies, and histories of childhood abuse, we explored the interaction between the NOS1AP gene and childhood maltreatment on the pathogenesis of ASPD. The results showed that polymorphism rs945713 in the NOS1AP gene was associated with ASPD and furthermore that this SNP may be involved in regulating the effect of childhood abuse on ASPD. This study found that childhood trauma increases the risk of ASPD in violent adult male inmates; for prisoners with ASPD, it is critical to pay attention to their childhood trauma and take early psychological intervention.

Branched-chain amino acids linked to depression in young adults

Depression is a heterogeneous mental health problem affecting millions worldwide, but a majority of individuals with depression do not experience relief from initial treatments. Therefore, we need to improve our understanding of the biology of depression. Metabolomic approaches, especially untargeted ones, can suggest new hypotheses for further exploring biological mechanisms. Using the FinnTwin12 cohort, a longitudinal Finnish population-based twin cohort, with data collected in adolescence and young adulthood including 725 blood plasma samples, we investigated associations between depression and 11 low–molecular weight metabolites (amino acids and ketone bodies). In linear regression models with the metabolite (measured at age 22) as the dependent variable and depression ratings (measured at age 12, 14, 17, or 22 from multiple raters) as independent variables [adjusted first for age, sex, body mass index (BMI), and additional covariates (later)], we initially identified a significant negative association of valine with depression. Upon further analyses, valine remained significantly negatively associated with depression cross-sectionally and over time [meta-analysis beta = −13.86, 95% CI (−18.48 to −9.25)]. Analyses of the other branched-chain amino acids showed a significant negative association of leucine with depression [meta-analysis beta = −9.24, 95% CI (−14.53 to −3.95)], while no association was observed between isoleucine and depression [meta-analysis beta = −0.95, 95% CI (−6.00 to 4.11)]. These exploratory epidemiologic findings support further investigations into the role of branched-chain amino acids in depression.

The protective role of mindful parenting against child maltreatment and aggressive behavior: an exploratory study among Chinese parent-adolescent dyads

BACKGROUND

It is well-established that child maltreatment practiced by parents is associated with adolescent aggression. Emerging evidence has suggested that higher levels of mindful parenting are associated with fewer negative parenting practices. However, the relationships among mindful parenting, child maltreatment, and adolescent aggression remain unclear.

AIM

To examine the association between mindful parenting, child maltreatment, and adolescent aggressive behavior among Chinese parent-adolescent dyads.

METHODS

Survey data from 554 Chinese parent-adolescent dyads were used for the analysis. Parents reported mindful parenting, and adolescents reported three forms of child maltreatment (i.e., physical abuse, psychological aggression, and neglect) by their parents and aggressive behavior. Path models were used to analyze whether higher levels of mindful parenting were associated with decreased likelihood of parent-to-adolescent maltreatment that were further related to lower levels of adolescent aggression.

RESULTS

Mindful parenting and its two factors (i.e., interaction with full attention and compassion and acceptance) were associated with lower likelihood of physical abuse and psychological aggression, which were related to decreased levels of adolescent aggressive behavior. Stratified analyses by parent gender showed that the path from interaction with full attention to adolescent aggression through psychological aggression was also significant or marginally significant in both mother-adolescent and father-adolescent dyads. Stratified analyses by adolescent gender demonstrated that the paths from interaction with full attention to physical abuse and psychological aggression were significant, which were also significantly correlated with adolescent aggression among male adolescents, whereas the mindful parenting-child maltreatment-adolescent aggression paths were not significant among female adolescents.

CONCLUSIONS

The findings contributed to the existing literature by assessing mindful parenting as a multifaceted construct and exploring the gender differences in the relationships. Gender-tailored interventions to improve mindful parenting, specifically focusing on the parents' ability of interacting with adolescents providing full attention, compassion, and acceptance may work towards preventing child maltreatment and promoting adolescent behavioral health.

The remediating effect of Attention Bias Modification on aggression in young offenders with antisocial tendency: A randomized controlled trial

BACKGROUND AND OBJECTIVES

An attention bias toward hostile stimuli is associated with an increased risk of aggressive behavior. Thus, reducing hostile attention bias may help to reduce aggression in young offenders. We evaluated the remediating effects of Attention Bias Modification (ABM) on hostile attention bias and aggressive behavior in Chinese male young offenders with antisocial tendencies.

METHODS

Institutionalized male young offenders (ages 16-18) were recruited and randomly assigned to ABM (n = 28), placebo (n = 28), or waiting list (n = 28). The ABM group received four weeks of training using visual search of emotional faces; the placebo group underwent similar training using visual search of neutral objects. Before and after treatment, aggressive behavior, attention bias toward positive stimuli and hostile stimuli were assessed.

RESULTS

Linear mixed models and hierarchical multiple regression analyses showed that the intervention effect of ABM was moderated by participants' initial attention bias. Young offenders with a high level of initial hostile attention bias, or with a low level of initial positive attention bias, benefitted most from ABM.

LIMITATIONS

The small sample size impedes investigation of the mechanism of the intervention's effects. Further research can determine whether the current results can be extrapolated to the population of female young offenders.

CONCLUSION

The results of the present study suggest that ABM is helpful for young offenders who show the greatest bias toward hostile stimuli and away from positive stimuli. These findings highlight the importance of matching the intervention and the participant.

TRIAL REGISTRATION

osf.io/vj5rk.

Adolescents' Attachment to Parents and Reactive-Proactive Aggression: The Mediating Role of Alexithymia

Aggressive behaviors can serve different functions, which might be understood by distinguishing between reactive (RA) and proactive (PA) aggression. Few studies were conducted on adolescents’ family precursors and emotional processes associated with RA or PA. Accordingly, the current study compared RA and PA by evaluating their association with adolescents’ attachment to parents and alexithymia. N = 453 Italian adolescents aged 15–19 years (Mage = 16.48; SD = 0.69; 33.6% males) participated in the study filling in self-report measures. Results showed that PA and RA are significantly associated and that PA was higher among males. Moreover, four mediational models were performed to assess the influence of adolescents’ attachment to mothers vs. fathers on RA or PA, considering the mediating role of alexithymia. Gender was included as a covariate. Mediational models’ results showed a direct and indirect effect, through lower alexithymia, of adolescents’ attachment to mothers and fathers on RA. Differently, only attachment to mothers showed a direct effect on PA, while attachment to fathers only an indirect effect, mediated by lower alexithymia, on PA was shown. Findings support the greater relevance of emotional processes for RA while highlighting the differential contribution of adolescents’ attachment to mothers vs. fathers upon PA. Implications are discussed, and suggestions for future research are provided.

A systematic review of the persistence of childhood mental health problems into adulthood

Many adult mental disorders have their origins in childhood yet our knowledge about this largely comes from studies assessing adults utilising retrospective recall of age of onset. In this systematic review we evaluate the current state of knowledge of how childhood exposure to mental health problems is associated with adult mental disorders using data from prospective longitudinal studies. We identified 40 studies that assessed mental health in childhood or adolescence and reassessed adults for mental disorders. Although there was substantial heterogeneity across studies in terms of methodology and findings, there was a clear pattern that experiencing mental health problems prior to 14 years of age increases risk of adult mental disorder. Importantly, elevated symptoms rather than diagnosis in childhood were generally more strongly associated with adult disorder. These findings provide strong support for the argument that prevention needs to be targeted to children in the primary school years and early intervention efforts to those who are beginning to experience elevated symptoms rather than waiting until a diagnosable disorder is evident.

Genetic association study of childhood aggression across raters, instruments, and age

Childhood aggressive behavior (AGG) has a substantial heritability of around 50%. Here we present a genome-wide association meta-analysis (GWAMA) of childhood AGG, in which all phenotype measures across childhood ages from multiple assessors were included. We analyzed phenotype assessments for a total of 328 935 observations from 87 485 children aged between 1.5 and 18 years, while accounting for sample overlap. We also meta-analyzed within subsets of the data, i.e., within rater, instrument and age. SNP-heritability for the overall meta-analysis (AGGoverall) was 3.31% (SE = 0.0038). We found no genome-wide significant SNPs for AGGoverall. The gene-based analysis returned three significant genes: ST3GAL3 (P = 1.6E-06), PCDH7 (P = 2.0E-06), and IPO13 (P = 2.5E-06). All three genes have previously been associated with educational traits. Polygenic scores based on our GWAMA significantly predicted aggression in a holdout sample of children (variance explained = 0.44%) and in retrospectively assessed childhood aggression (variance explained = 0.20%). Genetic correlations (rg) among rater-specific assessment of AGG ranged from rg = 0.46 between self- and teacher-assessment to rg = 0.81 between mother- and teacher-assessment. We obtained moderate-to-strong rgs with selected phenotypes from multiple domains, but hardly with any of the classical biomarkers thought to be associated with AGG. Significant genetic correlations were observed with most psychiatric and psychological traits (range [Formula: see text]: 0.19-1.00), except for obsessive-compulsive disorder. Aggression had a negative genetic correlation (rg = ~-0.5) with cognitive traits and age at first birth. Aggression was strongly genetically correlated with smoking phenotypes (range [Formula: see text]: 0.46-0.60). The genetic correlations between aggression and psychiatric disorders were weaker for teacher-reported AGG than for mother- and self-reported AGG. The current GWAMA of childhood aggression provides a powerful tool to interrogate the rater-specific genetic etiology of AGG.

Teacher-rated aggression and co-occurring behaviors and emotional problems among schoolchildren in four population-based European cohorts

Aggressive behavior in school is an ongoing concern. The current focus is on specific manifestations such as bullying, but the behavior is broad and heterogenous. Children spend a substantial amount of time in school, but their behaviors in the school setting tend to be less well characterized than at home. Because aggression may index multiple behavioral problems, we used three validated instruments to assess means, correlations and gender differences of teacher-rated aggressive behavior with co-occurring externalizing/internalizing problems and social behavior in 39,936 schoolchildren aged 7-14 from 4 population-based cohorts from Finland, the Netherlands, and the UK. Correlations of aggressive behavior were high with all other externalizing problems (r: 0.47-0.80) and lower with internalizing problems (r: 0.02-0.39). A negative association was observed with prosocial behavior (r: -0.33 to -0.54). Mean levels of aggressive behavior differed significantly by gender. Despite the higher mean levels of aggressive behavior in boys, the correlations were notably similar for boys and girls (e.g., aggressive-hyperactivity correlations: 0.51-0.75 boys, 0.47-0.70 girls) and did not vary greatly with respect to age, instrument or cohort. Thus, teacher-rated aggressive behavior rarely occurs in isolation; boys and girls with problems of aggressive behavior likely require help with other behavioral and emotional problems. Important to note, higher aggressive behavior is not only associated with higher amounts of other externalizing and internalizing problems but also with lower levels of prosocial behavior.

Exploring the Influence of Parenting Style on Adolescents’ Maladaptive Game Use through Aggression and Self-Control

Adolescent aggression manifests in problematic game use and ultimately undermines life quality. This study deals with the mechanisms behind adolescents’ perception of parenting, maladaptive game use, self-control, and life satisfaction within the context of integrated supportive-positive parenting and harsh-negative parenting. Using 778 valid panel data from the Korea Creative Content Agency (KOCCA), we reached the conclusions that both supportive-positive parenting and harsh-negative parenting, mediated by self-control and maladaptive game use, are major predictors of adolescents’ life satisfaction. PLS-SEM analysis was used for the hypothesized model test. This study helped bridge the gap in existing research by finding clues to recovering parent–child relationships from the side effects of youth game use.

Attentional variability and avoidance of hostile stimuli decrease aggression in Chinese male juvenile delinquents

BACKGROUND

As a prominent issue worldwide, juveniles' aggressive and violent crimes have attracted much interest in recent years. Based on the social information processing model, the present study aimed to evaluate the Chinese male juvenile delinquents' attention bias towards hostile stimuli from both static and dynamic perspectives. Additionally, the predictive effect of attention bias on aggressive behavior and the moderating effect of group (juvenile delinquents and the controls with no criminal history) were also investigated.

METHODS

The hostile attention bias and aggressive behavior of 76 juvenile delinquents (M_age = 17.5 years, SD = 0.59 years) and 67 controls (M_age = 18.3 years, SD = 0.73 years) were measured with the emotional dot-probe task, emotional Stroop task, and the Chinese version of the Buss & Perry aggression questionnaire, respectively.

RESULTS

The results showed that compared with controls, juvenile delinquents showed more attention biases towards hostile faces and words, and demonstrated higher levels of physical aggression and anger. Furthermore, the type of participants moderated the relationship between hostile attention bias and aggressive behavior. For juvenile delinquents, attention bias away from hostile stimuli and attention variability negatively predicted anger, while for controls, attention variability positively predicted self-directed aggression.

CONCLUSION

Attentional variability and avoidance of hostile stimuli are expected to reduce the aggressive level of Chinese male juvenile delinquents. The relationship between attention bias and aggression should be further considered and applied in the clinical practice.

Ketone body 3-hydroxybutyrate as a biomarker of aggression

Human aggression is a complex behaviour, the biological underpinnings of which remain poorly known. To gain insights into aggression biology, we studied relationships with aggression of 11 low-molecular-weight metabolites (amino acids, ketone bodies), processed using ¹H nuclear magnetic resonance spectroscopy. We used a discovery sample of young adults and an independent adult replication sample. We studied 725 young adults from a population-based Finnish twin cohort born 1983-1987, with aggression levels rated in adolescence (ages 12, 14, 17) by multiple raters and blood plasma samples at age 22. Linear regression models specified metabolites as the response variable and aggression ratings as predictor variables, and included several potential confounders. All metabolites showed low correlations with aggression, with only one-3-hydroxybutyrate, a ketone body produced during fasting-showing significant (negative) associations with aggression. Effect sizes for different raters were generally similar in magnitude, while teacher-rated (age 12) and self-rated (age 14) aggression were both significant predictors of 3-hydroxybutyrate in multi-rater models. In an independent replication sample of 960 adults from the Netherlands Twin Register, higher aggression (self-rated) was also related to lower levels of 3-hydroxybutyrate. These exploratory epidemiologic results warrant further studies on the role of ketone metabolism in aggression.

Harmonizing behavioral outcomes across studies, raters, and countries: application to the genetic analysis of aggression in the ACTION Consortium

BACKGROUND

Aggression in children has genetic and environmental causes. Studies of aggression can pool existing datasets to include more complex models of social effects. Such analyses require large datasets with harmonized outcome measures. Here, we made use of a reference panel for phenotype data to harmonize multiple aggression measures in school-aged children to jointly analyze data from five large twin cohorts.

METHODS

Individual level aggression data on 86,559 children (42,468 twin pairs) were available in five European twin cohorts measured by different instruments. A phenotypic reference panel was collected which enabled a model-based phenotype harmonization approach. A bi-factor integration model in the integrative data analysis framework was developed to model aggression across studies while adjusting for rater, age, and sex. Finally, harmonized aggression scores were analyzed to estimate contributions of genes, environment, and social interaction to aggression. The large sample size allowed adequate power to test for sibling interaction effects, with unique dynamics permitted for opposite-sex twins.

RESULTS

The best-fitting model found a high level of overall heritability of aggression (~60%). Different heritability rates of aggression across sex were marginally significant, with heritability estimates in boys of ~64% and ~58% in girls. Sibling interaction effects were only significant in the opposite-sex twin pairs: the interaction effect of males on their female co-twin differed from the effect of females on their male co-twin. An aggressive female had a positive effect on male co-twin aggression, whereas more aggression in males had a negative influence on a female co-twin.

CONCLUSIONS

Opposite-sex twins displayed unique social dynamics of aggressive behaviors in a joint analysis of a large, multinational dataset. The integrative data analysis framework, applied in combination with a reference panel, has the potential to elucidate broad, generalizable results in the investigation of common psychological traits in children.

Impulsive and premeditated aggression in male offenders with antisocial personality disorder

INTRODUCTION

Aggression is a clinical symptom of various psychiatric disorders that can be conceptualised as a physical act towards another person with the intent to cause harm. In antisocial personality disorder (ASPD), aggression is a frequent manifestation that differently compromise therapeutic and prognostic goals according to its impulsive or premeditated categorisation. ASPD is characterised by high levels of impulsivity, psychopathic traits, and a high prevalence of co-morbid substance use disorders (SUDs). Aggression in ASPD patients may determine long and recurrent imprisonment thus representing a challenge clinicians and legal experts face.

OBJECTIVES

Our aims were to characterise impulsive and premeditated aggression in male ASPD offenders as well as to determine the potential role of SUDs, impulsivity, and psychopathic traits as predictors.

MATERIALS AND METHODS

In this cross-sectional study we evaluated a sample of ASPD offenders with a battery of clinical and psychometric, standardised instruments: the Psychopathy Checklist-Revised (PCL-R), the European Version of the Addiction Severity Index (EuropASI), the Barratt Impulsivity Scale Version 11 (BIS-11), and the Impulsive/Premeditated Aggression Scale (IPAS).

RESULTS

We used a total sample of 134 offenders, all of whom were male. ASPD patients (n = 96) had a 71.9% prevalence of impulsive aggression and a 28.1% prevalence of premeditated aggression. ASPD patients with impulsive aggression had significantly lower scores of total PCL-R (p<0.01) factor 1 and interpersonal facet 1 (p<0.05), compared with ASPD patients with premeditated aggression. ASPD patients with impulsive aggression and ASPD patients with premeditated aggression had comparable BIS-11 mean scores, and exhibited an equal prevalence of SUDs. The interpersonal facet 1of the PCL-R predicted the aggression type (p<0.05) in ASPD patients, and the exponential beta value for facet 1 was 1.42 (CI = 1.03; 1.95).

CONCLUSIONS

The aggression type that is associated with ASPD is mainly impulsive in nature. ASPD patients who have higher scores of psychopathic traits have a lower probability of exhibiting impulsive aggression and a higher probability of exhibiting premeditated aggression. Although ASPD patients have high levels of impulsivity and a high frequency of SUDs, these two variables were not predictors of the aggression type.

FinnTwin12 Cohort: An Updated Review

This review offers an update on research conducted with FinnTwin12 (FT12), the youngest of the three Finnish Twin Cohorts. FT12 was designed as a two-stage study. In the first stage, we conducted multiwave questionnaire research enrolling all eligible twins born in Finland during 1983-1987 along with their biological parents. In stage 2, we intensively studied a subset of these twins with in-school assessments at age 12 and semistructured poly-diagnostic interviews at age 14. At baseline, parents of intensively studied twins were administered the adult version of the interview. Laboratory studies with repeat interviews, neuropsychological tests, and collection of DNA were made of intensively studied twins during follow-up in early adulthood. The basic aim of the FT12 study design was to obtain information on individual, familial and school/neighborhood risks for substance use/abuse prior to the onset of regular tobacco and alcohol use and then track trajectories of use and abuse and their consequences into adulthood. But the longitudinal assessments were not narrowly limited to this basic aim, and with multiwave, multirater assessments from ages 11 to 12, the study has created a richly informative data set for analyses of gene-environment interactions of both candidate genes and genomewide measures with measured risk-relevant environments. Because 25 years have elapsed since the start of the study, we are planning a fifth-wave follow-up assessment.