Impact of asthma medication and familial factors on the association between childhood asthma and attention-defict/hyperactivity disorder : a combined twin- and register-based study

BACKGROUND: Asthma and attention-deficit/hyperactivity disorder (ADHD) are prevalent in childhood and may cause functional impairment and stress in families. Previous research supports an association between asthma and ADHD in children, but several aspects of this relationship are unclear. OBJECTIVE: Our aim was to study whether the association between asthma and ADHD is restricted to either the inattentive or the hyperactive/impulsive symptoms of ADHD, to explore the impact of asthma severity and asthma medication and the contribution of shared genetic and environmental risk factors on the asthma-ADHD relationship. METHODS: Data on asthma, ADHD, zygosity and possible confounders were collected from parental questionnaires at 9 or 12 years on 20 072 twins through the Swedish Twin Register, linked to the Swedish Medical Birth Register, the National Patient Register and the Prescribed Drug Register. The association between asthma and ADHD, the impact of asthma severity and medication, was assessed by generalized estimating equations. Cross-twin-cross-trait correlations (CTCT) were estimated to explore the relative importance of genes and environment for the association. RESULTS: Asthmatic children had a higher risk of also having ADHD [odds ratio (OR) 1.53, 95% confidence interval (CI): 1.16-2.02]. The association was not restricted to either of the two dimensions of ADHD. The magnitude of the association increased with asthma severity (OR 2.84, 95% CI: 1.86-4.35) for ≥ 4 asthma attacks in the last 12 months and was not affected by asthma treatment. The CTCTs possibly indicate that the genetic component in overlap of the disorders is weak. CONCLUSIONS AND CLINICAL RELEVANCE: Childhood asthma, especially severe asthma, is associated with ADHD. Asthma medication seems not to increase the risk of ADHD. Clinicians should be aware of the potential of ADHD in asthma. Optimal asthma care needs to be integrated with effective evaluation and treatment of ADHD in children with co-existing disordersNoneNoneAccepte

Birth weight as an independent predictor of ADHD symptoms : a within-twin pair analysis

BACKGROUND: Studies have found an association between low birth weight and ADHD, but the nature of this relation is unclear. First, it is uncertain whether birth weight is associated with both of the ADHD dimensions, inattentiveness and hyperactivity-impulsivity. Second, it remains uncertain whether the association between birth weight and ADHD symptom severity is confounded by familial factors. METHOD: Parents of all Swedish 9- and 12-year-old twins born between 1992 and 2000 were interviewed for DSM-IV inattentive and hyperactive-impulsive ADHD symptoms by the Autism - Tics, AD/HD and other Comorbidities (A-TAC) inventory (N= 21,775 twins). Birth weight was collected prospectively through the Medical Birth Registry. We used a within-twin pair design to control for genetic and shared environmental factors. RESULTS: Reduced birth weight was significantly associated with a mean increase in total ADHD (beta = -.42; 95% CI: -.53, -.30), inattentive (beta = -.26; 95% CI: -.33, -.19), and hyperactive-impulsive (beta = -.16; 95% CI: -.22, -.10) symptom severity. These results imply that a change of one kilogram of birth weight corresponded to parents rating their child nearly one unit higher (going from "no" to "yes, to some extent" on a given symptom) on the total ADHD scale. These associations remained within pairs of MZ and DZ twins, and were also present when restricting the analyses to full term births. CONCLUSIONS: There is an independent association between low birth weight and all forms of ADHD symptoms, even after controlling for all environmental and genetic confounds shared within twin pairs. These results indicate that fetal growth restriction (as reflected in birth weight differences within twin pairs) and/or the environmental factors which influence it is in the casual pathway leading to ADHD.The Swedish Council for Working Life and Social ResearchThe Swedish Research CouncilManuscrip

Motor function and perception in children with neuropsychiatric and conduct problems : results from a population based twin study.

BACKGROUND: Children with early symptomatic psychiatric disorders such as Attention-Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) have been found to have high rates of motor and/or perception difficulties. However, there have been few large-scale studies reporting on the association between Conduct Disorder (CD) and motor/perception functions. The aim of the present study was to investigate how motor function and perception relate to measures of ADHD, ASD, and CD. METHODS: Parents of 16,994 Swedish twins (ages nine and twelve years) were interviewed using the Autism-Tics, ADHD and other Comorbidities inventory (A-TAC), which has been validated as a screening instrument for early onset child psychiatric disorders and symptoms. Associations between categorical variables of scoring above previously validated cut-off values for diagnosing ADHD, ASD, and CD on the one hand and motor and/or perception problems on the other hand were analysed using cross-tabulations, and the Fisher exact test. Associations between the continuous scores for ADHD, ASD, CD, and the subdomains Concentration/Attention, Impulsiveness/Activity, Flexibility, Social Interaction and Language, and the categorical factors age and gender, on the one hand, and the dependent dichotomic variables Motor control and Perception problems, on the other hand, were analysed using binary logistic regression in general estimated equation models. RESULTS: Male gender was associated with increased risk of Motor control and/or Perception problems. Children scoring above the cut-off for ADHD, ASD, and/or CD, but not those who were 'CD positive' but 'ADHD/ASD negative', had more Motor control and/or Perception problems, compared with children who were screen-negative for all three diagnoses. In the multivariable model, CD and Impulsiveness/Activity had no positive associations with Motor control and/or Perception problems. CONCLUSIONS: CD symptoms or problems with Impulsiveness/Activity were associated with Motor control or Perception problems only in the presence of ASD symptoms and/or symptoms of inattention. Our results indicate that children with CD but without ASD or inattention do not show a deviant development of motor and perceptual functions. Therefore, all children with CD should be examined concerning motor control and perception. If problems are present, a suspicion of ADHD and/or ASD should be raised.The Swedish Research CouncilThe Swedish Research Council for Health, Working Life and WelfarePublishe

Childhood attention-deficit/hyperactivity disorder symptoms and the development of adolescent alcohol problems : a prospective, population-based study of Swedish twins.

Children with attention-deficit/hyperactivity disorder (ADHD) are at increased risk of problematic alcohol and other substance use in adolescence. This study used data from an ongoing, prospective, population-based twin study of Swedish children and adolescents to evaluate the extent to which the association between ADHD symptoms and alcohol problems reflects a unique source of genetic or environmental risk related to ADHD versus a broader predisposition to youth externalizing behavior. We used all available data from same-sex MZ and DZ twins on ADHD symptoms in childhood (age 9/12; N = 15,549) and alcohol problems in late adolescence (age 18; N = 2,564). Consistent with prior longitudinal studies, the phenotypic association between hyperactive/impulsive ADHD symptoms and alcohol problems was small in magnitude, whereas the association for inattentive symptoms was even weaker. Additive genetic influences explained 99.8% of the association between hyperactive/impulsive symptoms and alcohol problems. Furthermore, we found that the genetic risk specifically associated with hyperactive/impulsive symptoms was attenuated when estimated in the context of externalizing behavior liability during childhood, of which ADHD symptoms were specific expressions. In sensitivity analyses exploring hyperactivity in mid-adolescence, we found a similar pattern of genetic associations. These results are consistent with previous findings of genetically driven overlap in the etiology of ADHD and problematic alcohol use. At least some of this cooccurrence may result from a general predisposition to externalizing behaviors in youth.National Institutes of Health (NIH), MH102221, TR001107Swedish Initiative for Research on Microdata in the Social and Medical Sciences (SIMSAM)Swedish Research Council for Health Working Life & Welfare (Forte)Swedish Research CouncilSöderström-Königska FoundationEuropean Commission, 602768NIH National Center for Advancing Translational Sciences (NCATS), TL1TR001107, UL1TR001108NIH National Institute of Mental Health (NIMH), R01MH102221Manuscrip

Effects of autism spectrum disorders on outcome in teenage-onset anorexia nervosa evaluated by the Morgan-Russell outcome assessment schedule: a controlled community-based study

Background: The purpose of the study was to evaluate time trends and effects of co-existing autism spectrum disorders (ASD) on outcome in an ongoing long-term follow-up study of anorexia nervosa (AN). Methods: The Morgan-Russell Outcome Assessment Schedule (MROAS) was used at 6-, 10- and 18-year follow-up of a representative sample of 51 individuals with teenage-onset AN and a matched group of 51 healthy comparison cases. The full multinomial distribution of responses for the full scale and each of the subscales was evaluated using exact nonparametric statistical methods. The impact of diagnostic stability of ASD on outcome in AN was evaluated in a dose–response model. Results: There were no deaths in either group. Food intake and menstrual pattern were initially poor in the AN group but normalised over time. MROAS ‘mental state’ was much poorer in the AN group and did not improve over time. The psychosexual MROAS domains ‘attitudes’ and ‘aims’ showed persistent problems in the AN group. In the MROAS socioeconomic domain, the subscales ‘personal contacts’, ‘social activities’ and ‘employment record’ all showed highly significant between-group differences at all three follow-ups. A statistically significant negative dose–response relationship was found between a stable diagnosis of ASD over time and the results on the subscales ‘mental state’, ‘psychosexual state’ and ‘socio-economic state’. Conclusions: Outcome of teenage-onset AN is favourable with respect to mortality and persisting eating disorder, but serious problems remain in the domains ‘mental state’, ‘psychosexual function’ and ‘socioeconomic state’. Outcome is considerably worse if ASD is present. Treatment programmes for AN need to be modified so as to accommodate co-existing ASD

Offenders in emerging adulthood : School maladjustment, childhood adversities, and prediction of aggressive antisocial behaviors

Early psychosocial adversities and maladjustment, such as childhood maltreatment and school adjustment problems, have been linked to an increased risk of aggressive antisocial behaviors. Yet, clinical studies of subjects at the highest risk of persistence in such behaviors are rare, especially during the life-changing transition years of emerging adulthood. This study describes early predictors of aggressive antisocial behaviors in a large, nationally representative cohort of Swedish, male violent offenders in emerging adulthood (age range = 18-25 years; N = 270). First, data on psychosocial background characteristics and aggressive antisocial behaviors (including age at onset) are provided. Second, early predictors of aggressive antisocial behaviors are tested in bivariate and multivariate interactive models. The offenders demonstrated a diversity of early onset adversities and disruptive behaviors, in line with established risk factors for subsequent criminality and adverse outcomes in a variety of life domains. Severe school adjustment problems, especially bullying others and early onset truancy, were important and interrelated predictors of aggressive antisocial behaviors over the lifetime, whereas childhood adversities such as parental substance or alcohol abuse and repeated exposure to violence at home during childhood were interrelated predictors of aggressive antisocial behaviors, albeit with less statistical importance. The findings stress the importance of early identification of individuals in the risk zone of developing severe and persistent aggressive antisocial behaviors and of early preventive interventions directed toward families with high-risk profiles. The findings also provide initial guidelines on which psychosocial background risk factors that need to be considered first-hand in early interventions. (PsycINFO Database Recor

The 1 % of the population accountable for 63 % of all violent crime convictions

PURPOSE: Population-based studies on violent crime and background factors may provide an understanding of the relationships between susceptibility factors and crime. We aimed to determine the distribution of violent crime convictions in the Swedish population 1973–2004 and to identify criminal, academic, parental, and psychiatric risk factors for persistence in violent crime. METHOD: The nationwide multi-generation register was used with many other linked nationwide registers to select participants. All individuals born in 1958–1980 (2,393,765 individuals) were included. Persistent violent offenders (those with a lifetime history of three or more violent crime convictions) were compared with individuals having one or two such convictions, and to matched non-offenders. Independent variables were gender, age of first conviction for a violent crime, nonviolent crime convictions, and diagnoses for major mental disorders, personality disorders, and substance use disorders. RESULTS: A total of 93,642 individuals (3.9 %) had at least one violent conviction. The distribution of convictions was highly skewed; 24,342 persistent violent offenders (1.0 % of the total population) accounted for 63.2 % of all convictions. Persistence in violence was associated with male sex (OR 2.5), personality disorder (OR 2.3), violent crime conviction before age 19 (OR 2.0), drug-related offenses (OR 1.9), nonviolent criminality (OR 1.9), substance use disorder (OR 1.9), and major mental disorder (OR 1.3). CONCLUSIONS: The majority of violent crimes are perpetrated by a small number of persistent violent offenders, typically males, characterized by early onset of violent criminality, substance abuse, personality disorders, and nonviolent criminality

Association between ASMT and autistic-like traits in children from a Swedish nationwide cohort

Persons with autism spectrum disorders (ASDs) often display low levels of melatonin, and it has been suggested that this decrease may be due to low activity of the acetylserotonin O-methyltransferase (ASMT), the last enzyme in the melatonin synthesis pathway. Moreover, genetic variants in ASMT have been associated with autism, as well as with low ASMT activity and melatonin levels, suggesting that the low ASMT activity observed in autism may partly be due to variation within the ASMT gene. In this study, we present a symptom-based approach to investigate possible associations between ASMT and autistic-like traits (ALTs) in the general population. To this end, continuous measures of ALTs were assessed in a nationally representative twin cohort (n=1771) from Sweden and six Single Nucleotide Polymorphisms (SNP) and a duplication of exon 2 to 8 in ASMT were genotyped. Our results show a nominally significant association, in girls, between one SNP (rs5949028) in the last intron of ASMT and social interaction impairments. No significant association, however, was observed with traits related to language impairment or restricted and repetitive behavior. In conclusion, our results support the possible involvement of the ASMT gene in ASDs and our finding that only one of three traits shows association suggests that genetic research may benefit from taking a symptom-specific approach to identify genes involved in autism psychopathology.VetenskapsrådetAccepte

Associations between oxytocin-related genes and autistic-like traits.

Oxytocin has repeatedly been shown to influence human behavior in social contexts; also, a relationship between oxytocin and the pathophysiology of autism spectrum disorder (ASD) has been suggested. In the present study, we investigated single-nucleotide polymorphisms (SNPs) in the oxytocin gene (OXT) and the genes for single-minded 1 (SIM1), aryl hydrocarbon receptor nuclear translocator 2 (ARNT2) and cluster of differentiation 38 (CD38) in a population of 1771 children from the Child and Adolescent Twin Study in Sweden (CATSS). Statistical analyses were performed to investigate any association between SNPs and autistic-like traits (ALTs), measured through ASD scores in the Autism-Tics, ADHD and other Co-morbidities inventory. Firstly, we found a statistically significant association between the SIM1 SNP rs3734354 (Pro352Thr) and scores for language impairment (p = .0004), but due to low statistical power this should be interpreted cautiously. Furthermore, nominal associations were found between ASD scores and SNPs in OXT, ARNT2 and CD38. In summary, the present study lends support to the hypothesis that oxytocin and oxytocin neuron development may have an influence on the development of ALTs and suggests a new candidate gene in the search for the pathophysiology of ASD.The Swedish Research CouncilThe Swedish Research Council for Health, Working Life and WelfareThe Swedish Brain FoundationSvenska Sällskapet för Medicinsk Forskning (SSMF)Fredrik and Ingrid Thurings stiftelseÅke Wibergs stiftelseÅhlén-stiftelsenJeanssons-stiftelsenMagnus Bergvalls stiftelseSöderström-Königska stiftelsenMärta Lundqvists stiftelsethe Novo Nordisk FoundationAccepte