ADHD, autism spectrum disorder, temperament, and character: phenotypical associations and etiology in a Swedish childhood twin study

Using the Infant Sibling-Design to Explore Associations Between Autism and ADHD Traits in Probands and Temperament in the Younger Siblings

The purpose of the current study was to use the infant sibling design to explore whether proband traits of autism and ADHD could provide information about their infant sibling's temperament. This could help us to gain information about the extent to which infant temperament traits are differentially associated with autism and ADHD traits. We used parent-ratings of autistic traits and ADHD traits (CRS-3) in older siblings diagnosed with autism (age range 4 to 19 years), and their infant siblings' temperament traits (IBQ) at 9 months of age in 216 sibling pairs from two sites (BASIS, UK, and EASE, Sweden) to examine associations across siblings. We found specific, but modest, associations across siblings after controlling for sex, age, developmental level and site. Proband autistic traits were specifically related to low levels of approach in the infant siblings, with infant developmental level explaining part of the variance in infant approach. Proband ADHD traits were specifically related to high levels of infant activity even after controlling for covariates. Our findings suggest that proband traits of autism and ADHD carry information for infant sibling's temperament, indicating that inherited liability may influence early emerging behaviours in infant siblings. The impact of sex, age, developmental level and site are discussed.

Continuity of temperament subgroup classifications from infancy to toddlerhood in the context of early autism traits

Our previous cross-sectional investigation (Chetcuti et al., 2020) showed that infants with autism traits could be divided into distinct subgroups based on temperament. This longitudinal study builds on this existing work by exploring the continuity of temperament subgroup classifications and their associations with behavioral/clinical phenotypic features from infancy to toddlerhood. 103 infants (68% male) showing early signs of autism were referred to the study by community healthcare professionals and seen for assessments when aged around 12-months (Time 1), 18-months (Time 2), and 24-months (Time 3). Latent profile analysis revealed inhibited/low positive, active/negative reactive, and sociable/well-regulated subgroups at each timepoint, and a unique reactive/regulated subgroup at Time 3. Cross-tabulations indicated a significant likelihood of children having a recurrent subgroup classification from one timepoint to the next, and no apparent patterns to the movement of children who did change from one subgroup to another over time. Temperament subgroups were associated with concurrent child social-emotional functioning and autism traits, but unrelated to child age, sex, or developmental level. These findings suggest that temperament subgroup classifications might represent a reliable and very early indicator of autism characteristics and social-emotional functioning among infants/toddlers with autism traits.

Lower Risk of Burn Injury in Children and Adolescents with Autism Spectrum Disorder: A Nationwide Population-Based Study

Little research has examined burn injury in the pediatric population with autism spectrum disorder (ASD). We used data from Taiwan's National Health Insurance Research Database to identify 15,844 participants aged <18 years with ASD and 130,860 participants without ASD. Our results revealed that the hazard ratios differed across three age ranges. The ASD group had a lower risk of burn injury than the non-ASD group when they were less than 6 years of age, a higher risk from 6 years to 12 years of age, and no difference when they were older than 12 years of age. More research is required to study the characteristics and causes of burn injury in the pediatric population with ASD.

Exploring the Link between ADHD and Obesity: A Focus on Temperament

Multiple studies support the relationship between ADHD and overweight/obesity in youth. Different mechanisms may be involved, such as temperamental and psychopathological factors. The aim of this study was to test the hypothesis that specific temperamental and psychopathological dimensions could mediate the relationship between ADHD and obesity. The sample included 100 children and adolescents (78 males and 22 females; age range 6 to 18 years; mean age 9.90 ± 2.5 years). The assessment procedure included Conners' Parent Rating Scale-Long (CPRS-R:L) as the inclusion criterion for ADHD diagnosis, the Child Behavior Checklist (CBCL), a dimensional measure for psychopathology, and the Junior Temperament and Character Inventory, which describes four temperamental dimensions: novelty seeking (NS), harm avoidance (HA), reward dependence (RD), and persistence (P). While in the whole ADHD sample, the highest scores were found in NS and the lowest in P, ADHD with overweight/obesity, compared to ADHD with normal weight, showed higher HA and RD, lower NS, and higher CBCL Internalizing scores. These findings suggest that ADHD youth with overweight/obesity present specific temperamental and psychopathological features compared to those without overweight/obesity. If confirmed in larger samples, using a control group without ADHD, these temperamental and psychological features may be helpful for an earlier recognition of ADHD patients at higher risk for obesity, and may represent possible targets for temperament-based preventive interventions and tailored treatment programs. These features should be included in the routine assessment of children and adolescents with ADHD and/or are overweight/obese.

Is the temperamental trait of high persistence protective in siblings? - A comparative, exploratory study of healthy siblings, and attention deficit hyperactivity disorder probands

BACKGROUND

Study of temperament in first-degree relatives is an important line of inquiry to substantiate temperament as an etiological marker.

AIM

This study aims to compare temperament in children with attention deficit hyperactivity disorder (ADHD) and their healthy siblings and to assess the association between ADHD symptoms and temperament dimensions in healthy siblings.

SETTINGS AND DESIGN

The study was carried out in the outpatient department of psychiatry in a tertiary care teaching hospital. A cross-sectional design with nonprobabilistic sampling technique was used for data collection.

MATERIALS AND METHODS

A hundred children (50 children with ADHD and 50 siblings-one for each child with ADHD) were assessed retrospectively on temperament measurement schedule (TMS) and conners parent rating scale-revised: short form (CPRS-R: S).

STATISTICAL ANALYSIS

IBM SPSS Statistics for Windows, Version 20.0 was used for statistical analysis. Mean and standard deviation and frequency and percentage were computed for continuous and categorical variables, respectively. Student's t-test was computed to compare means of the two groups and regression analysis was computed to see for the variance in ADHD subscale scores explained by temperament scores on TMS.

RESULTS

Siblings scored highest on the intensity of reaction and lowest on threshold of responsiveness. Compared to probands, siblings scored significantly higher on persistence and lower on activity level, even after controlling for gender. Persistence trait had a significant negative correlation with and explained 7.4% to 21% of variance of all CPRS-R: S subscales. Persistence and distractibility together explained 23.2% of inattention scores.

CONCLUSION

Higher persistence in siblings appears to offer protection to these at-risk individuals who do not have ADHD; favoring the dual pathway model of ADHD.

Temperament in individuals with Autism Spectrum Disorder: A systematic review

The study of temperament in Autism Spectrum Disorder (ASD) has the potential to provide insight regarding variability in the onset, nature, and course of both core and co-morbid symptoms. The aim of this systematic review was to integrate existing findings concerning temperament in the context of ASD. Searches of Medline, PsychInfo and Scopus databases identified 64 relevant studies. As a group, children and adolescents with ASD appear to be temperamentally different from both typically developing and other clinical non-ASD groups, characterized by higher negative affectivity, lower surgency, and lower effortful control at a higher-order level. Consistent with research on typically developing children, correlational findings and emerging longitudinal evidence suggests that lower effortful control and higher negative affect are associated with increased internalizing and externalizing problems in ASD samples. Longitudinal studies suggest there may be temperamental differences between high familial risk infants who do and do not develop ASD from as early as 6-months of age. Limitations of existing research are highlighted, and possible directions for future research to capitalize on the potential afforded through the study of temperament in relation to ASD are discussed.

Right Posterior Insula and Putamen Volume Mediate the Effect of Oxytocin Receptor Polygenic Risk for Autism Spectrum Disorders on Reward Dependence in Healthy Adults

Much evidence indicates the influence of the oxytocin receptor (OXTR) gene on autism spectrum disorders (ASDs), a set of disorders characterized by a range of deficits in prosocial behaviors, which are closely related to the personality trait of reward dependence (RD). However, we do not know the effect of the OXTR polygenic risk score for ASDs (OXTR-PRSASDs) on RD and its underlying neuroanatomical substrate. Here, we aimed to investigate associations among the OXTR-PRSASDs, gray matter volume (GMV), and RD in two independent datasets of healthy young adults (n = 450 and 540). We found that the individuals with higher OXTR-PRSASDs had lower RD and significantly smaller GMV in the right posterior insula and putamen. The GMV of this region showed a positive correlation with RD and a mediation effect on the association between OXTR-PRSASDs and RD. Moreover, the correlation map between OXTR-PRSASDs and GMV showed spatial correlation with OXTR gene expression. All results were highly consistent between the two datasets. These findings highlight a possible neural pathway by which the common variants in the OXTR gene associated with ASDs may jointly impact the GMV of the right posterior insula and putamen and further affect the personality trait of RD.

The nature and nurture of ADHD and its comorbidities: A narrative review on twin studies

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in children worldwide, and also the recognition of its persistence into adulthood is increasing. While ADHD in childhood is highly heritable and mostly driven by familial factors, during adulthood it appears to show a lower heritability, even if there is not total agreement on this yet. This disorder often co-occurs with many other conditions, which also vary across the different stages of development, and several studies have used the twin design to investigate these comorbidities, giving valuable insights into the origins of the observed co-occurrence. This review aims to summarize the main results of twin research, according to the following domains: individual traits, cognitive impairment, behavioral manifestations, clinical conditions and psychosocial risk factors. Individual features seem to play a role in this symptomatology and include personality traits such as negative emotionality, personality disorders and temperamental dimensions with a predominance of novelty seeking. At a lower level, ADHD is associated with both functional and anatomic brain characteristics. ADHD is also associated with some forms of cognitive impairment, such as sluggish cognitive tempo, and learning disabilities, with a specific predisposition to reading disability. In addition, ADHD is strongly associated with externalizing disorders such as conduct disorder and oppositional defiant disorder, and some behavioral outcomes, particularly substance use and abuse both in adolescence and adulthood. Moreover, ADHD symptoms often overlap with other psychological disorders, namely affective and internalizing disorders, as well as autism spectrum disorder and autistic-like traits in a wider sense. Notably, a genetic overlap has been found between asthma and ADHD, particularly with respect to hyperactivity/impulsivity dimensions. ADHD also appears to represent a risk factor for disordered eating, and, more specifically, for binge eating and bulimia nervosa. Finally, among psychosocial factors, an association has been proposed between childhood maltreatment and ADHD symptoms.

Low blood lead levels and attention-deficit hyperactivity disorder in children: a systematic review and meta-analysis

Attention-deficit hyperactivity disorder (ADHD) of children is one of the most common neurodevelopmental diseases; the etiology remains unclear. We reviewed and meta-analyzed case-control studies to assess the effects of blood lead levels in children on ADHD symptoms. Relevant studies were identified by searching electronic databases. A meta-analysis was performed using the fixed model of Review Manager 5.3 software. Seven relevant studies were identified. The case groups exhibited significant increases in ADHD symptoms [mean difference (MD), 0.59; 95% confidence interval (CI), 0.50-0.68; p < 0.0001]. Subgroup assessment showed that even children with blood lead levels <3 μg/dL exhibited significant increases in ADHD symptoms (MD, 0.47; 95% CI, 0.39-0.56; p < 0.0001). Subgroup assessment also showed that children aged 5-12 years exhibited more significant increases in ADHD symptoms (MD, 1.35; 95% CI, 0.28-2.41; p < 0.0001) than children aged >12 years. Our findings suggest that low blood lead levels may be associated with ADHD symptoms in children. However, caution is needed when interpreting the results because among-study heterogeneity was in play. Primary interventions should focus on children with low blood lead levels.

Psychiatric genetics and the structure of psychopathology

For over a century, psychiatric disorders have been defined by expert opinion and clinical observation. The modern DSM has relied on a consensus of experts to define categorical syndromes based on clusters of symptoms and signs, and, to some extent, external validators, such as longitudinal course and response to treatment. In the absence of an established etiology, psychiatry has struggled to validate these descriptive syndromes, and to define the boundaries between disorders and between normal and pathologic variation. Recent advances in genomic research, coupled with large-scale collaborative efforts like the Psychiatric Genomics Consortium, have identified hundreds of common and rare genetic variations that contribute to a range of neuropsychiatric disorders. At the same time, they have begun to address deeper questions about the structure and classification of mental disorders: To what extent do genetic findings support or challenge our clinical nosology? Are there genetic boundaries between psychiatric and neurologic illness? Do the data support a boundary between disorder and normal variation? Is it possible to envision a nosology based on genetically informed disease mechanisms? This review provides an overview of conceptual issues and genetic findings that bear on the relationships among and boundaries between psychiatric disorders and other conditions. We highlight implications for the evolving classification of psychopathology and the challenges for clinical translation.

Imprisoning Yoga: Yoga Practice May Increase the Character Maturity of Male Prison Inmates

Background: A specific personality profile, characterized by low character maturity (low scores on the self-directedness and cooperativeness character dimensions) and high scores on the novelty seeking temperament dimension of the temperament and character inventory (TCI), has been associated with aggressive antisocial behavior in male prison inmates. It has also been shown that yoga practiced in Swedish correctional facilities has positive effects on the inmates' well-being and on risk factors associated with criminal recidivism (e.g., antisocial behavior). In this study, we aimed to investigate whether the positive effect of yoga practice on inmates' behaviors could be extended to include eventual changes in their personality profile. Methods: Male prison inmates (N = 111) in Sweden participated in a randomized controlled 10-week long yoga intervention trial. Participants were randomly assigned to either a yoga group (one class a week; n = 57) or a control group (free of choice weekly physical activity; n = 54). All the inmates completed the TCI questionnaire before and after the intervention period as part of an assessment battery. Results: After the 10-week-long intervention period male inmates scored significantly lower on the novelty seeking and the harm avoidance and significantly higher on the self-directedness dimensions of the TCI. There was a significant medium strong interaction effect between time and group belonging for the self-directedness dimension of character favoring the yoga group. Conclusion: A 10-week-long yoga practice intervention among male inmates in Swedish correctional facilities increased the inmates' character maturity, improving such abilities as their capability to take responsibility, feel more purposeful, and being more self-acceptant-features that previously were found to be associated with decreased aggressive antisocial behavior.

Temperament and character profiles for children with ADHD with and without tic disorders

There is no research about whether ADHD with tic disorder that temperamental features that differ from the ADHD. This research aimed to identify temperament and character profiles for children with ADHD according to tic disorder by comparing them with a healthy control group. A discriminant analysis was conducted to identify whether temperament and character profiles can discriminate comorbidity. The sample consisted of three groups (N = 40 per group): ADHD alone, ADHD with tic disorder and age- and sex- matched healthy control. The parents of 120 children (mean age 8.57 ± 1.71 years) completed the Junior Temperament and Character Inventory (JTCI). The two ADHD groups showed higher novelty seeking and low persistence, self-directedness and cooperativeness than the control group. The ADHD alone group had lower scores for persistence and self-directedness than the other two groups. Temperament and character profiles were useful for discriminating ADHD from the control group. However, their discriminating power was relatively low for all three groups. Results indicated that differences in temperament and character in ADHD children were present according to comorbid tic disorders. JTCI's discriminating power for ADHD alone and ADHD with tic disorder was relatively lower than that of the combined ADHD group and the control group.

Temperament and character in men with autism spectrum disorder: A reanalysis of scores on the Temperament and Character Inventory by individual case matching

BACKGROUND

Interest in autism spectrum disorders (ASD) in adulthood is increasing. Although a person may be diagnosed with ASD, the diagnosis reveals little about the individual's temperament, character, and personality. Also, relatively little is known about the personality of adults with ASD.

METHOD

A reanalysis of scores on the Temperament and Character Inventory (TCI) administered to a group of 66 normally intelligent men aged 18-63 years, diagnosed with ASD, by individual case matching to a comparison group of 66 men from the general population drawn from the TCI manual.

RESULTS

Compared to the comparison group, men with ASD scored significantly higher on the scale for Harm Avoidance, and lower on Novelty Seeking, Reward Dependence, Self-Directedness, and Cooperativeness.

CONCLUSIONS

In this study the score pattern for temperament and character found in men with ASD by individual case matching confirms and strengthens earlier general group matching findings emerging from our 2012 study and from studies from Sweden and the Netherlands.

The Relations Between Temperament, Character, and Executive Functions in Children With ADHD and Clinical Controls

OBJECTIVE

The purpose of this study was to investigate the overlap between executive functions and temperament as measured by two questionnaires and to examine characteristic profiles in children with ADHD and clinical controls.

METHOD

Parents of 111 clinically referred children, half of whom were diagnosed with ADHD and half with other or no diagnoses, completed the Behavior Rating Inventory of Executive Function (BRIEF) and the Cloninger Junior Temperament and Character Inventory (JTCI).

RESULTS

Factor analysis of both instruments resulted in three common factors representing aspects of (1) cognitive regulation, (2) behavioral regulation, and (3) anxious/rigid tendencies. Factor (4) represented strengths and positive resources and loaded on JTCI scales only. Both instruments discriminated significantly between ADHD and non-ADHD children. Conduct disorder/oppositional defiant disorder (CD/ODD) but not ADHD accounted for problems in BRIEF Emotional Control and Self-Monitor and JTCI low Cooperativeness.

CONCLUSION

The two instruments only partially overlap and may complement each other.

Ratings of Broader Autism Phenotype and Personality Traits in Optimal Outcomes from Autism Spectrum Disorder

The study examines whether "optimal outcome" (OO) children, despite no longer meeting diagnostic criteria for Autism Spectrum Disorder (ASD), exhibit personality traits often found in those with ASD. Nine zero acquaintance raters evaluated Broader Autism Phenotype (BAP) and Big Five personality traits of 22 OO individuals, 27 high functioning individuals with ASD (HFA), and 23 typically developing (TD) peers. HFA children displayed higher ratings than their peers on all BAP traits. OO were indistinguishable from TD, with the exception of greater extraversion (e.g., increased talkativeness), a potential tendency to be less emotionally stable, and pragmatic language deficits such as getting sidetracked in conversation. Overall, OO individuals are not showing BAP characteristics, but may be subject to other mild ADHD-like characteristics.

The protective effect of character maturity in child aggressive antisocial behavior

BACKGROUND

Childhood aggressive antisocial behavior (CD) is one of the strongest predictors of mental health problems and criminal behavior in adulthood. The aims of this study were to describe personality profiles in children with CD, and to determine the strength of association between defined neurodevelopmental symptoms, dimensions of character maturity and CD.

METHODS

A sample of 1886 children with a close to equal distribution of age (9 or 12) and gender, enriched for neurodevelopmental and psychiatric problems were selected from the nationwide Child and Adolescent Twin Study in Sweden. Their parents rated them according to the Junior Temperament and Character Inventory following a telephone interview during which information about the children's development and mental health was assessed with the Autism-Tics, AD/HD and other Comorbidities inventory.

RESULT

Scores on the CD module significantly and positively correlated with scores on the Novelty Seeking temperament dimension and negatively with scores on character maturity (Self-Directedness and Cooperativeness). In the group of children with either neurodevelopmental or behavioral problems, the prevalence of low or very low character maturity was 50%, while when these two problems coexisted the prevalence of low or very low character maturity increased to 70%. Neurodevelopmental problems (such as: oppositional defiant disorder, symptoms of attention deficit/hyperactivity disorder and autism spectrum disorder) and low scores on character maturity emerged as independently significant predictors of CD; in a multivariable model, only oppositional defiant symptoms and impulsivity significantly increased the risk for coexisting CD while a mature self-agency in a child (Self-Directedness) remained a significant protective factor.

CONCLUSION

These results suggest that children's willpower, the capacity to achieve personally chosen goals may be an important protective factor - even in the presence of neurodevelopmental and psychiatric problems - against progressing into persistent negative outcomes, such as aggressive antisocial behaviors.

Personality and trait aggression profiles of male and female prison inmates

Gender specific personality profiles in association with the level of aggressive antisocial behavior in offenders have not been previously investigated. In the present study we analyzed data collected from 65 male and 50 female offenders using structured protocols regarding criminal history (by criminal register data), trait aggression (by the Life History of Aggression (LHA) questionnaire), and personality profiles (by the Temperament and Character Inventory (TCI)). Prison inmates differed significantly on several personality dimensions, most pronouncedly were they characterized with low character maturity (low scores in the Self-Directedness and Cooperativeness dimensions of TCI) when compared to gender and age matched controls of the general population. The majority of offenders scored distinctively high on trait aggression. There were moderate to strong associations between the personality dimensions and each of the subscales of LHA (Aggression, Self-directed Aggression and Antisocial behavior). These associations were stronger in the female offender sample. Trait aggression could be best explained by a model, which included male gender, younger age, high novelty seeking temperament and low character maturity. Our results suggest that therapies aiming at strengthening self-governance and increasing cooperativeness (focusing on character maturity) may alleviate aggressive antisocial behavior in offenders.

Attention-deficit/hyperactivity disorder and eating disorders across the lifespan: A systematic review of the literature

Attention-deficit/hyperactivity disorder (ADHD) and eating disorders are common and concerning mental health disorders. There is both empirical and theoretical support for an association between ADHD and eating disorders or disordered eating. This systematic review aims to summarize the extant literature on the comorbidity of ADHD and eating disorders across the lifespan, including the influences of sex, age, eating disorder diagnosis, and potential mediators. A total of 37 peer-reviewed studies on diagnosed ADHD and eating disturbances were identified through key research databases. Twenty-six studies supported a strong empirical association between ADHD and eating disorders or disordered eating. The systematic review findings suggest that children with ADHD are at risk for disordered eating, while adolescents, emerging adults, and adults are at risk for both eating disorders and disordered eating. Methodological considerations, future research, and clinical implications are discussed.

Self-regulated compliance in preschoolers with autism spectrum disorder: The role of temperament and parental disciplinary style

Regulatory difficulties are common in children with autism spectrum disorder. This study focused on an important aspect of self-regulation—the ability to willingly comply with frustrating demands of socialization agents, termed “self-regulated compliance.” We studied compliance to parental demands in 40 preschoolers with autism spectrum disorder and 40 matched typically developing preschoolers, during separate interactions with mother and father, while engaging in two paradigms: toy pick-up and delayed gratification, which tap the “do” and “don’t” aspects of self-regulated socialization at this age. Parents’ disciplinary style was micro-coded from the two paradigms and child temperament was parent reported. Compared to their typically developing peers, children with autism spectrum disorder showed more noncompliance and less self-regulated compliance to parental demands and prohibitions and greater temperamental difficulties across several domains. No group differences were found in parental disciplinary style. Child self-regulated compliance was associated with parental supportive disciplinary style and with child attention focusing. Findings highlight the importance of parental supportive presence in structuring the development of socialization in children with autism spectrum disorder. Implications for parent–child emotion regulation interventions are discussed.

The connection of temperament with ADHD occurrence and persistence into adulthood - An investigation in 18 year old males

BACKGROUND

This study intended to determine whether certain traits of temperament are associated with former and current ADHD symptomatology in a non-clinical sample of 18 year old males.

METHODS

We performed a cross sectional descriptive study of 3280 men during the examination for military service. The investigation included a socio-demographic questionnaire, screening for substance abuse, temperament (TEMPS-M), past (WURS) and current (ADHD symptom checklist) ADHD symptomatology.

RESULTS

We found a correlation of cyclothymic (p<.001), irritable (p<.001) and anxious (p<.05) temperament with occurrence and severity of past and present ADHD symptomatology. No significant correlation has been detected for hyperthymic and depressive temperament. Judged retrospectively, ADHD symptoms were strongly consistent over time.

LIMITATIONS

The sample consists of men only. These had to be fit enough to be enlisted for military service; men with severe mental or physical disorders were thus excluded. Furthermore, the cross-sectional study design does not allow making conclusions about the temporal relationships between ADHD symptoms and substance misuse.

CONCLUSIONS

These results indicate that a temperament based approach towards those affected by ADHD might be useful. Subtyping ADHD by integrating temperament profiles in diagnosis and treatment of the disorder could help explain some of the heterogeneity of the disease.

Personality profiles in adults with attention deficit hyperactivity disorder (ADHD)

BACKGROUND

Previous studies suggested that the presence of ADHD in children and young adolescents may affect the development of personality. Whether or not the persistence of ADHD in adult life is associated with distinct personality patterns is still matter for debate. To address this issue, we compared the profiles of the Temperament and Character Inventory (TCI) that assesses personality dimensions in 119 adults ADHD and 403 controls.

METHODS

ANCOVA were used to examine group differences (controls vs. ADHD and ADHD inattentive type vs. ADHD combined + hyperactive/impulsive types) in Temperaments and Characters. Partial correlation coefficients were used to assess correlation between TCI and expression and severity of symptoms of ADHD.

RESULTS

High novelty seeking (NS), harm avoidance (HA) and self-transcendence (ST) scores as well as low self-directedness (SD) and cooperativeness (C) scores were associated with ADHD diagnosis. Low SD was the strongest personality trait associated with adult ADHD. Cases with the ADHD inattentive type showed higher HA and lower SD scores compared to the combined and hyperactive/impulsive types. High HA scores correlated with inattention symptoms whereas high NS and ST scores were related to hyperactive symptoms. Finally low SD and high NS were associated with increased ADHD severity.

CONCLUSIONS

Distinct temperaments were associated with inattentive versus hyperactive/impulsive symptoms supporting the heterogeneous nature of the disorder.

Personality disorders and Axis I comorbidity in adolescent outpatients with ADHD

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a lifelong condition which carries great cost to society and has an extensive comorbidity. It has been assumed that ADHD is 2 to 5 times more frequent in boys than in girls. Several studies have suggested developmental trajectories that link ADHD and certain personality disorders. The present study investigated the prevalence of ADHD, common Axis I disorders, and their gender differences in a sample of adolescent outpatients. We also wanted to investigate the relationship between ADHD and personality disorders (PDs), as well as how this relationship was influenced by adjustment for Axis I disorders, age and gender.

METHODS

We used a sample consisting of 153 adolescents, aged 14 to 17 years, who were referred to a non-specialized mental health outpatient clinic with a defined catchment area. ADHD, conduct disorder (CD) and other Axis I conditions were assessed using the Mini International Neuropsychiatric Interview (MINI). PDs were assessed using the Structured Interview for DSM-IV Personality (SIDP-IV).

RESULTS

13.7 % of the adolescents met diagnostic criteria for ADHD, with no significant gender difference. 21.6 % had at least one PD, 17.6 % had CD, and 4.6 % had both ADHD and a PD. There was a significantly elevated number of PD symptoms in adolescents with an ADHD diagnosis (p = 0.001), and this relationship was not significantly weakened when adjusted for age, gender and other Axis I disorders (p = 0.026). Antisocial (χ (2) = 21.18, p = 0.002) and borderline (χ (2) = 6.15, p = 0.042) PDs were significantly more frequent in girls than in boys with ADHD.

CONCLUSIONS

We found no significant gender difference in the prevalence of ADHD in a sample of adolescents referred to a general mental health outpatient clinic. Adolescent girls with ADHD had more PDs than boys, with antisocial and borderline PDs significantly different. The present study suggests that ADHD in girls in a general outpatient population may be more prevalent than previously assumed. It especially highlights the importance of assessing antisocial and borderline personality pathology in adolescent girls presenting with ADHD symptoms.

Comorbidity of Personality Disorders and Adult Attention Deficit Hyperactivity Disorder (ADHD)--Review of Recent Findings

Children suffering from attention deficit hyperactivity disorder (ADHD) may remit until adulthood. But, more than 60-80% have persisting ADHD symptoms. ADHD as an early manifesting neurodevelopmental disorder is considered a major risk factor for the development of comorbid psychiatric disorders in later life. Particularly, personality disorders are oftentimes observed in adult patients suffering from ADHD. If ADHD and personality disorders share common etiological mechanisms and/or if ADHD as a severely impairing condition influences psychological functioning and learning and leads to unfavorable learning histories is unclear. The development of inflexible and dysfunctional beliefs on the basis of real and perceived impairments or otherness due to the core symptoms of ADHD is intuitively plausible. Such beliefs are a known cause for the development of personality disorders. But, why some personality disorders are more frequently found in ADHD patients as for example antisocial and borderline personality disorder remains subject of debate. Because of the high prevalence of ADHD and the high impact of personality disorders on daily functioning, it is important to take them into account when treating patients with ADHD. Research on the developmental trajectories leading to personality disorders in adult ADHD patients might open the door for targeted interventions to prevent impairing comorbid clinical pictures.

An update on the comorbidity of ADHD and ASD: a focus on clinical management

Attention deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) commonly co-occur. With the DSM-5, clinicians are permitted to make an ASD diagnosis in the context of ADHD. In earlier versions of the DSM, this was not acceptable. Both ASD and ADHD are reported to have had substantial increases in prevalence within the past 10 years. As a function of both the increased prevalence of both disorders as well as the ability to make an ASD diagnosis in ADHD, there has been a significant amount of research focusing on the comorbidity between ADHD and ASD in the past few years. Here, we provide an update on the biological, cognitive and behavioral overlap/distinctiveness between the two neurodevelopmental disorders with a focus on data published in the last four years. Treatment strategies for the comorbid condition as well as future areas of research and clinical need are discussed.

Aggressive Antisocial Behaviors Are Related to Character Maturity in Young Swedish Violent Offenders Independent of ADHD

BACKGROUND

Antisocial personality and psychopathic traits have constantly been found to accompany criminal and aggressive behaviors, but little attention has been given to aspects of character maturity and its relation to such behaviors. The present study investigated (1) whether level of character maturity (low, medium, and high) is associated with amount of aggressive antisocial behaviors (AABs) and psychopathic traits in young men imprisoned for violent criminality, and (2) whether such an association is independent of coexisting attention-deficit hyperactivity disorder (ADHD).

METHODS

Swedish males (N = 270, aged 18-25) sentenced to prison for violent and/or sexual criminality in the western region of the Swedish Prison and Probation Service underwent a thorough clinical examination during their incarceration. Data on character maturity, as measured by the character dimensions Self-Directedness and Cooperativeness of the Temperament and Character Inventory, were available for n = 148 subjects and were used to divide these offenders into three groups with low, medium, and high character maturity. These groups were then compared for variables reflecting criminal history, a DSM-IV diagnosis of ADHD, conduct disorder (CD) and substance use disorders (SUD), aggressive behaviors, and psychopathic traits.

RESULTS

Character maturity was consistently associated with less AABs and psychopathic personality traits; the group with the highest character maturity showed: (i) a later age at onset of criminality, (ii) a smaller number of prior violent criminal acts, (iii) lower prevalence of ADHD, CD, and SUD, (iv) less self-rated and expert-rated aggressive behaviors, and (v) less psychopathic traits. The association between character maturity and aggressive behaviors/psychopathic personality traits remained even when ADHD was controlled for. The only exception was sexual criminality, where the group with the highest character maturity contained the largest amount of sexual offenders.

CONCLUSION

Higher character maturity appeared to be a protective factor among young male violent offenders, associated with less AABs, suggesting that character maturity is a promising target for treatment interventions for this group of individuals.

Social Novelty Investigation in the Juvenile Rat: Modulation by the μ-Opioid System

The drive to approach and explore novel conspecifics is inherent to social animals and may promote optimal social functioning. Juvenile animals seek out interactions with novel peers more frequently and find these interactions to be more rewarding than their adult counterparts. In the present study, we aimed to establish a behavioural paradigm to measure social novelty-seeking in juvenile rats and to determine the involvement of the opioid, dopamine, oxytocin and vasopressin systems in this behaviour. To this end, we developed the social novelty preference test to assess the preference of a juvenile rat to investigate a novel over a familiar (cage mate) conspecific. We show that across the juvenile period both male and female rats spend more time investigating a novel conspecific than a cage mate, independent of subject sex or repeated exposure to the test. We hypothesised that brain systems subserving social information processing and social motivation/reward (i.e. the opioid, dopamine, oxytocin, vasopressin systems) might support social novelty preference. To test this, receptor antagonists of each of these systems were administered i.c.v. prior to exposure to the social novelty preference test and, subsequently, to the social preference test, to examine the specificity of these effects. We find that μ-opioid receptor antagonism reduces novel social investigation in both the social novelty preference and social preference tests while leaving the investigation of a cage mate (social novelty preference test) or an object (social preference test) unaffected. In contrast, central blockade of dopamine D2 receptors (with eticlopride), oxytocin receptors (with des-Gly-NH2,d(CH2)5[Tyr(Me)2,Thr4]OVT) or vasopressin V1a receptors [with (CH2)5Tyr(Me2)AVP] failed to alter social novelty preference or social preference. Overall, we have established a new behavioural test to study social novelty-seeking behaviour in the juvenile rat and show that the μ-opioid system facilitates this behaviour, possibly by reducing risk avoidance and enhancing the hedonic and/or motivational value of social novelty.

Personality and intelligence: persistence, not self-directedness, cooperativeness or self-transcendence, is related to twins' cognitive abilities

Background. A person-centered approach focusing on the interaction of an individual’s temperament-character-life events is essential in the path of individuals’ well-being. In this context, three character traits, Self-directedness (e.g., self-acceptance, self-control, goal-directed behavior), Cooperativeness (e.g., social affiliation, social tolerance, empathy and helpfulness) and Self-transcendence (e.g., spiritual acceptance, transpersonal identification), measured using Cloninger’s model of personality are suggested to help the individual to regulate and resolve the conflicts derived from her/his temperament combinations as a reaction to life events. However, if character is related to the individual’s cognitive ability, then this association might limit any intervention that focuses on character development. We used data from the Child and Adolescent Twin Study in Sweden (CATSS) to investigate the relationship between personality and cognitive ability.

Method. The sample consisted of 370 15-year-old twins (159 girls/211 boys), 192 of whom screen-positive with various types of mental health problems. We used the Temperament and Character Inventory to measure personality and the Wechsler Intelligence Scales for Children (WISC-IV) to measure intelligence. The relationship was investigated using correlation analyses using random-selected twins from each dyad and separately for monozygotic and dizygotic twins. Additional analyses investigated the genetic and environmental effects on personality and cognitive ability in this specific sample.

Results. There were no significant correlations between the WISC-IV indices and any of the character traits (i.e., Self-directedness, Cooperativeness, and Self-transcendence). Persistence was significantly related, if weak, to four WISC-IV indices: Verbal Comprehension, Perceptual Reasoning, Working Memory, and the Full WISC-IV Scale. Post-hoc cross-twin/cross-trait analyses showed that the Persistence-cognitive ability correlation might depend on common genetic effects. The WISC-IV indices showed a relatively large genetic influence, while earlier findings about the etiology of temperament and character traits using the whole CATSS sample were replicated in this sub-sample of twins.

Conclusions. The results indicate that what individuals make of themselves intentionally (i.e., their character) was not associated to intelligence. Persistence, a temperament dimension that measures heritable individual differences in eagerness of effort, ambition, perfectionism, and resistance to discouragement despite frustration and fatigue, was weakly linked to intelligence. Suggesting that, at least during adolescence, interventions targeting character development are not limited by the individual’s intelligence.

Relationship between temperament, character and the autistic trait in parents of children with autistic spectrum disorder

OBJECTIVE

Previous studies have revealed distinct features of autism, with higher harm avoidance and lower reward dependence and novelty seeking. It is assumed that high harm avoidance, and low novelty seeking, reward dependence, cooperativeness, and self-directedness are related with the broad autism phenotype, as seen in autistic individuals.

METHOD

This study examined the association between the Temperament and Character Inventory (TCI) and the Autism Spectrum Quotient (AQ), in parents of children with ASD.

RESULT

There was significant correlation between total AQ and total harm avoidance, cooperativeness, and self-directedness (p < 0.05). In the stepwise analysis, self-directedness and education emerged significantly (F(2,67) = 19.71, p < .005). This model modestly explained 35% of variance (Adjusted R(2) = .350).

CONCLUSION

Our findings suggest that self-directedness may be an autistic trait.

Increasing phenotypic and genetic variations in hyperactivity/inattention problems from age 3 to 13 years: a cross-sectional twin study

A twin design was used to examine the developmental nature of genetic, environmental, and phenotypic variations in hyperactivity and inattention problems (HIP). Mothers of 662 complete pairs of twins (273 monozygotic [MZ] pairs and 389 dizygotic [DZ] pairs) aged from 3 to 13 years (mean [SD] age = 8.3 [2.9] years) responded to the items of the HIP scale of the Strengths and Difficulties questionnaire via a telephone interview. Maximum likelihood MZ and DZ twin correlations in the total sample were 0.47 (95% CI: 0.37-0.55) and -0.01 (95% CI: -0.11-0.09). A standard univariate model incorporating age as a modifier was applied to the raw data. Results of model-fitting analyses showed that the phenotypic variation of HIP monotonically increased from age 3 to age 12 and that this increase was completely due to an increase in genetic variance, suggesting that it is genes that expand individual difference in ADHD symptoms with age during childhood. Child-specific environmental variance was constant during this age period. In terms of relative influences, total genetic factors increased from 33% (95% CI: 27-44%) at age 3 to 51% (95% CI: 28-71%) at age 13 and this increase was accompanied by a decrease in relative influences of child-specific environmental factors from 67% (95% CI: 56-73%) at age 3 to 49% (95% CI: 29-72%) at age 13. These estimates of genetic influences were somewhat lower than those found in most twin studies of ADHD symptoms. However, the increasing trend of genetic influences with age during childhood was consistent with the results of a recent meta-analysis of ADHD symptoms.

Advances in Genetic Discovery and Implications for Counseling of Patients and Families with Autism Spectrum Disorders

The prevalence of autism spectrum disorders (ASD) continues to increase. Genetic factors play an important role in the etiology of ASD, although specific genetic causes are identified in only a minority of cases. Recent advances have accelerated the discovery of genes implicated in ASD through convergent genomic analysis of genome-wide association studies, chromosomal microarray, exome sequencing, genome sequencing, and gene networks. Hundreds of candidate genes for ASD have been reported, yet only a handful have proven causative. Symptoms are complex and highly variable, and most cases are likely due to cumulative genetic factors, the interactions among them, as well as environmental factors. Here we summarize recent findings in genomic research regarding discovery of candidate genes, describe the major molecular processes in neural development that may be disrupted in ASD, and discuss the implication of research findings in clinical genetic diagnostic testing and counseling. Continued advances in genetic research will eventually translate into innovative approaches to prevention and treatment of ASD.

Self-directedness and cooperativeness, psychosocial dysfunction and suffering in ESSENCE

Background. The acronym ESSENCE (Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations) highlights that children seeking clinical treatment are often multiply impaired, thus requiring treatment from several specialties. The aim was to map and relate, on a population level, ESSENCE to two salient predictors of health and adaptation to adversities, namely, Self-Directedness and Cooperativeness and also to dysfunction and suffering. Methods. Participants were twins (N = 1892) aged 9 or 12 whose parents were interviewed with the Autism-Tics, ADHD and other Comorbidities inventory (A-TAC), and the Junior Temperament and Character Inventory (J-TCI). The A-TAC was first used to discern four ESSENCE-related screening diagnoses: autism spectrum disorders, attention deficit hyperactivity disorder, learning disabilities, and developmental coordination disorder; second, to quantify dysfunction and suffering in important social areas. Results. ESSENCE symptoms were continuously and categorically associated with deficiency in Self-Directedness and Cooperativeness and higher ratings of dysfunction and suffering. The impact of ESSENCE symptoms on these measures of mental health was found in a milder form in about 16% of all children and in a severe form in about 2%. Conclusion. Therapeutic interventions focusing on Self-Directedness and Cooperativeness might provide a novel method for child psychiatry in its approach to ESSENCE.