Long-term behavioural outcomes after paediatric convulsive status epilepticus: a population-based cohort study

AIM

To describe behavioural and psychiatric outcomes of children within 10 years of convulsive status epilepticus (CSE).

METHOD

Children originally identified by the population-based North London Convulsive Status Epilepticus in Childhood Surveillance Study were followed-up between July 2009 and February 2013. They were grouped into epilepsy- and non-epilepsy-related CSE, and compared with population norms and healthy controls using the Strengths and Difficulties Questionnaire; the Autism Spectrum Screening Questionnaire; and the Swanson, Nolan, and Pelham questionnaire. Children who scored above recommended clinical cut-offs on any scale were invited for a neuropsychiatric assessment. Regression models were fitted to identify clinically relevant covariates associated with behavioural outcomes.

RESULTS

At a mean follow-up of 8.1 years post-CSE, 28% of enrolled children were found to have a psychiatric disorder. Children with epilepsy-related CSE scored higher than norms on all scales and children with non-epilepsy-related CSE scored higher than norms on the Strengths and Difficulties Questionnaire and the Autism Spectrum Screening Questionnaire. Presence of seizures at baseline and recurrence of CSE was associated with worse outcomes in the group with epilepsy. Intellectual abilities were associated with behavioural outcomes in all participants.

INTERPRETATION

A large proportion of children manifest behavioural issues 8 years after CSE. The present data highlight the need for behavioural screening in children with neurodevelopmental impairments post-CSE.

WHAT THIS PAPER ADDS

Eight years post convulsive status epilepticus (CSE), 37% of parents report behavioural issues. Of enrolled children, 28% were found to have a Diagnostic and Statistical Manual mental disorder. Intellectual abilities are strongly associated with behavioural outcomes in children post-CSE.

Symptoms of depression, anxiety, and stress in parents of young children with epilepsy: A case controlled population-based study

The objective was to provide population-based data on depression, anxiety, and stress in parents of young children with epilepsy and to compare findings with those of parents of developmental-, age-, and gender-matched children with nonepilepsy-related neurodisability (neurological and/or neurodevelopmental concerns). The parents (mothers and fathers) of 47 (89% ascertainment) young children (1-7years) with epilepsy in a defined geographical area of the UK completed the Depression Anxiety Stress Scales - Short Form (DASS-21), a screening measure for depression, anxiety, and stress. The responses of parents of children with epilepsy were compared with parents of developmental-, age-, and gender-matched children with nonepilepsy-related neurodisability (n=48). Factors associated with parental symptoms were analyzed using regression. In the group with epilepsy, 47 mothers and 39 fathers completed the DASS-21. Seventy-two percent of mothers scored in the at-risk range on at least one DASS-21 subscale (Fathers 49%). Mothers of children with epilepsy were significantly more likely to score in the at risk range than fathers on depression (55% vs. 33%), anxiety (47% vs. 26%), and stress (55% vs. 31%) subscales (all p<0.05). Mothers of children with epilepsy were also significantly more likely to score in the at-risk range than mothers of children with neurodisability on measures of depression (p=0.005) and stress (p=0.03). There was not a significant difference between fathers in both groups on any measures. In the group with epilepsy, increased child emotional-behavioral difficulties were associated with increased DASS-21 scores on multivariable analysis (p=0.04). Mothers of young children with epilepsy are at high risk for mental health difficulties, and all should be screened for such difficulties. There is a need to explore what parent and/or child focused interventions might be useful to reduce the mental health difficulties reported by mothers of young children with epilepsy.

[Not Available]

Pupils in the 6th grade of compulsory schools (age 11-12 years) in representative municipalities in Sweden, participated in a study of cognitive capacity and "neurodevelopmental functioning" in relation to the new Swedish educational goals, set up by the National Agency for Education. Results from four subtests of the WISC-IV, the ESSENCE-Questionnaire, covering concerns regarding different developmental areas, information about educational support and about final subject grades were analysed. Of a total of 396 pupils, 229 (58%) agreed to participate. Pupils who had failed at least one subject had significantly lower cognitive test results and significantly more ESSENCE concerns, compared to those who passed in all subjects. In the group of pupils who had at least one failed subject, 89% had been given special educational support. The knowledge requirements in the new national curriculum need to be reviewed and adapted to these circumstances.

Examining the Association Between Autistic Traits and Atypical Sensory Reactivity: A Twin Study

OBJECTIVE

Atypical responses to sensory stimuli are common features of autism spectrum disorders (ASD). Consequently, atypical sensory reactivity (SR) is now a diagnostic feature of ASD. Quantitative genetic research on ASD has overlooked these symptoms, however. We therefore investigated the association between autistic traits and SR using twin methods.

METHOD

Autistic traits and SR were assessed by 2 separate scales in 12,419 Swedish twin pairs (n = 3,586 monozygotic [MZ], n = 8,833 dizygotic [DZ]) when the twins were 9 or 12 years of age. The classic twin design estimated the degree to which etiological factors associated with autistic traits were also associated with SR, and the degree to which such shared factors explained the covariance between these phenotypes. DeFries-Fulker analysis estimated the genetic correlation between screening diagnoses of ASD, defined broadly and strictly, and SR.

RESULTS

Autistic traits and SR were both highly heritable (62%-75% and 66%-71%, respectively). There was a moderate phenotypic correlation between autistic traits and SR (r = 0.47). Genetic influences on these phenotypes correlated moderately (genetic correlation = 0.60). These overlapping genetic factors explained most of the correlation between autistic traits and SR. Genetic correlations with SR increased for broad ASD (genetic correlation = 0.72) and strict ASD (genetic correlation = 0.80).

CONCLUSION

The genetic overlap observed between autistic traits and SR lends quantitative genetic support to the notion that ASD and SR are strongly linked. Such symptoms may thus comprise part of the ASD genotype, as well as phenotype. Associations persisted across all definitions of ASD, indicating a genetic link between the broader ASD phenotype and SR.

Young children who screen positive for autism: Stability, change and "comorbidity" over two years

BACKGROUND

Autism spectrum disorder (ASD) is a developmental disorder with a wide variety of clinical phenotypes and co-occurrences with other neurodevelopmental conditions. Symptoms may change over time.

AIMS

The aim of the present study was to prospectively follow 96 children, initially assessed for suspected ASD at an average age of 2.9 years.

METHODS AND PROCEDURES

All children had been identified with autistic symptoms in a general population child health screening program, and had been referred to the Child Neuropsychiatry Clinic in Gothenburg, Sweden for further assessment by a multi-professional team at Time 1 (T1). This assessment included a broad neurodevelopmental examination, structured interviews, a cognitive test and evaluations of the child́s adaptive and global functioning. Two years later, at Time 2 (T2), the children and their parents were invited for a follow-up assessment by the same team using the same methods.

OUTCOMES AND RESULTS

Of the 96 children, 76 had met and 20 had not met full criteria for ASD at T1. Of the same 96 children, 79 met full ASD criteria at T2. The vast majority of children with ASD also had other neurodevelopmental symptoms or diagnoses. Hyperactivity was observed in 42% of children with ASD at T2, and Intellectual Developmental Disorder in 30%. Borderline Intellectual Functioning was found in 25%, and severe speech and language disorder in 20%. The children who did not meet criteria for ASD at T2 had symptoms of or met criteria for other neurodevelopmental/neuropsychiatric disorders in combination with marked autistic traits. Changes in developmental profiles between T1 and T2 were common in this group of young children with ASD. The main effect of Cognitive level at T1 explained more than twice as much of the variance in Vineland scores as did the ASD subtype; children with IDD had significantly lower scores than children in the BIF and AIF group. Co-existence with other conditions was the rule.

CONCLUSIONS AND IMPLICATIONS

Reassessments covering the whole range of these conditions are necessary for an optimized intervention-adapted to the individual child's needs.

Children with autism spectrum disorders and selective mutism

BACKGROUND

It has been suggested that autism spectrum disorder (ASD) might be a "comorbid" condition in selective mutism (SM).

METHODS

In this retrospective study, we examined medical records of children with SM diagnosis (n=97) at a medical center specializing in assessment of ASD.

RESULTS

Mean age for onset of SM symptoms was 4.5 years and mean age at SM diagnosis was 8.8 years. SM was more common among girls (boy:girl ratio=2.7:1). We found that 63% of the study group had an ASD (no gender difference). The SM group with combined ASD had later onset of symptoms, higher age at diagnosis, more often a history of speech delay, and a higher proportion of borderline IQ or intellectual disability.

CONCLUSION

The results highlight the risk of overlap between ASD and SM.

Children screening positive for language delay at 2.5 years: language disorder and developmental profiles

PURPOSE

To characterize language disorder and developmental profiles in children who screened positive for language delay but negative for autism at 2.5 years of age.

PATIENTS AND METHODS

The first 100 children who screened positive for language delay - but negative for autism - in 2016 were assessed in detail by speech language pathologists. Parents completed a newly developed questionnaire covering eight domains - Motor, Executive functions, Perception, Memory, Language, Learning, Social skills and Child's behaviour - with impairment scored for each domain.

RESULTS

ICD-10 language disorder diagnoses were made in 87/100 children (29 girls, 58 boys). Of 52 children with mixed receptive-expressive language disorder, 32% had problems in other developmental areas according to the "global rating" in the impairment questions of the questionnaire. Of the 35 with expressive language disorder, 21% had problems in other areas according to the impairment questions. Thirteen children had isolated language delay with no other diagnoses according to the speech and language pathologists' assessment; however, 23% of them had problems according to the parental rating on the impairment questions.

CONCLUSION

Most children screening positive for language delay but negative for autism at age 2.5 years were diagnosed with ICD-10 language disorder diagnoses. Parents in about one in four cases reported impairing problems within other developmental areas. Possible explanations for the findings are discussed.

ESSENCE-Q: Slavic language versions for developmental screening in young children

PURPOSE

The Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations - Questionnaire (ESSENCE-Q) was developed as a brief screener to identify children with developmental concerns who might have neurodevelopmental disorders (NDDs). This study aimed to translate the ESSENCE-Q into south Slavic languages, namely, Bosnian, Bulgarian, Croatian, Macedonian, Montenegrin, Serbian, and Slovenian, and to evaluate its psychometric properties for screening purposes in clinical settings.

PATIENTS AND METHODS

In the study, the ESSENCE-Q was completed for 251 "typically developing" children and 200 children with 1 or more diagnosed NDDs, all aged 1-6 years. Internal consistency and construct validity were tested first, followed by generating receiver operating characteristic curves and the area under the curve. Optimal cutoff values were then explored.

RESULTS

The Cronbach's α coefficients were 0.91, 0.88, and 0.86 for ESSENCE-Q parent-completed form, and the telephone and direct interview forms administered by trained nurse or specialist, respectively. The 3 versions produced area under the curve values (95% confidence interval): 0.96 (0.93-0.99), 0.91 (0.86-0.95), and 0.91 (0.86-0.97), respectively. An optimal cutoff for ESSENCE-Q parent-completed form was found to be ≥3 points, while for the telephone and direct interviews, it was ≥5 points.

CONCLUSION

We found adequate measurement properties of the south Slavic languages versions of the ESSENCE-Q as a screener for NDDs in clinical settings. This study provided additional data supporting sound psychometric properties of the ESSENCE-Q.

Speech and language profiles in 4- to 6-year-old children with early diagnosis of autism spectrum disorder without intellectual disability

PURPOSE

This study aimed to present speech and language data from a community-representative group of 4- to 6-year-old children with early-diagnosed autism spectrum disorder (ASD) without intellectual disability (ID).

METHODS

The study group comprised 83 children 4-6 years of age with ASD without ID. They had been diagnosed with ASD before age 4.5 years and had received intervention at a specialized habilitation center. At 2-year follow-up, their language abilities were evaluated comprehensively by two speech-language pathologists using a battery of assessments. Receptive and expressive language and phonology were examined. The phonology evaluation included measures of phonological speech production and of phonological processing.

RESULTS

Results revealed that almost 60% had moderate-severe language problems. Nearly half exhibited combined expressive and receptive language problems, of which a majority also had phonology problems. Phonological speech problems were found in 21% of the total group.

CONCLUSION

The findings underscore the importance of considering speech/language disorders in children with ASD without ID, since they usually attend mainstream classes but need specific educational adaptations.

Autism traits: The importance of "co-morbid" problems for impairment and contact with services. Data from the Bergen Child Study

BACKGROUND

Co-occurring problems are common in individuals with clinical autism spectrum disorder (ASD) but their relevance for impairment and contact with health services in ASD is largely unexplored.

AIMS

We investigated the extent of co-occurring problems in children with high ASD traits from a total population sample. We explored the contribution of co-occurring problems to impairment and service contact, and whether there were children without co-occurring problems in this group; as proxy for "ASD only".

METHODS AND PROCEDURES

Children screening positive on the Autism Spectrum Screening Questionnaire (ASSQ) were used as proxy for ASD. Attention Deficit/Hyperactivity Disorder (ADHD) and Oppositional Defiant Disorder (ODD) were operationalised using symptom counts. A parent or teacher report above the 95th percentile counted as "problem" present for other symptom domains.

OUTCOMES AND RESULTS

92% of ASSQ high-scorers had a minimum of two other problems. Emotional problems, ADHD symptoms and learning problems were the most commonly reported problems, also predicting impairment and contact with services.

CONCLUSIONS AND IMPLICATIONS

Co-occurring problems were common in ASD screen positive children and contributed strongly to both impairment and to contact with services. Gender differences indicated that female symptoms were perceived as less impairing by parents and teachers.

The Autism-Tics, ADHD and other Comorbidities inventory (A-TAC): previous and predictive validity

BACKGROUND

Reliable and easy to administer screening instruments focusing on neurodevelopmental disorders and associated conditions are scarce. The Autism-Tics, AD/HD and other Comorbidities inventory (A-TAC) has previously been validated and reporting good- excellent validity for several disorders. This article aims to expand these findings by including more conditions in a substantially larger sample augmented with the Swedish National Patient Register (NPR).

METHODS

Since 2004 parents of all 9-year-old Swedish twins have been invited to participate in a telephone interview in the Child and Adolescent Twin Study in Sweden, CATSS. The CATSS is linked to the NPR which includes data from in- and outpatient care. Data on neurodevelopmental disorders (A-TAC) collected in CATSS were compared with diagnoses from the NPR. We investigated diagnoses that had been made both before (previous validity) and after (predictive validity) the interview.

RESULTS

Sensitivity and specificity of A-TAC scores for predicting earlier or later clinical diagnoses were mostly good-excellent, with values of the area under the curve for a clinical diagnosis of autism spectrum disorder (ASD) of .98, attention deficit hyperactivity disorder (ADHD) .93, learning disorder (LD) .92, and oppositional defiant disorder (ODD) .99, with small differences in terms of previous and predictive analyses. A-TAC provided little validity for eating disorders.

CONCLUSION

The result support previous claims: A-TAC is a broad screening instrument with a particular strength in assessing ASD, ADHD, LD, and ODD at ages 9 and 12, and also provides phenotypic information about other child psychiatric disorders.

Hypersensitivity to low intensity fearful faces in autism when fixation is constrained to the eyes

Previous studies that showed decreased brain activation in people with autism spectrum disorder (ASD) viewing expressive faces did not control that participants looked in the eyes. This is problematic because ASD is characterized by abnormal attention to the eyes. Here, we collected fMRI data from 48 participants (27 ASD) viewing pictures of neutral faces and faces expressing anger, happiness, and fear at low and high intensity, with a fixation cross between the eyes. Group differences in whole brain activity were examined for expressive faces at high and low intensity versus neutral faces. Group differences in neural activity were also investigated in regions of interest within the social brain, including the amygdala and the ventromedial prefrontal cortex (vmPFC). In response to low intensity fearful faces, ASD participants showed increased activation in the social brain regions, and decreased functional coupling between the amygdala and the vmPFC. This oversensitivity to low intensity fear coupled with a lack of emotional regulation capacity could indicate an excitatory/inhibitory imbalance in their socio-affective processing system. This may result in social disengagement and avoidance of eye-contact to handle feelings of strong emotional reaction. Our results also demonstrate the importance of careful control of gaze when investigating emotional processing in ASD. Hum Brain Mapp 38:5943-5957, 2017. © 2017 Wiley Periodicals, Inc.

Anxiety and depression in adolescents with ADHD and autism spectrum disorders; correlation between parent- and self-reports and with attention and adaptive functioning

BACKGROUND

Adolescents with attention-deficit/hyperactive disorder (ADHD) or autism spectrum disorder (ASD) are at high risk of anxiety and depression. This is important to identify in the clinical assessment to understand its impact.

AIMS

The aim of this study is to investigate the correlation between parent- and self-reports of anxiety and depression in adolescents with ADHD or ASD, as well as the correlation with adaptive functioning and performance on an attention test.

METHOD

A total of 65 adolescents with an ADHD diagnosis (n = 24) or an ASD diagnosis (n = 41) filled out Beck Youth Inventories of Emotional and Social Impairment (BYI) to assess depression and anxiety and completed a Continuous Performance Test (QbTest) measuring ADHD symptoms. Parents of the participants completed the internalizing domain in the Five to Fifteen questionnaire (FTF), measuring symptoms of anxiety and depression, and the Vineland Adaptive Behavior Scales (VABS) about the adolescent's adaptive functioning.

RESULTS

Approximately a third of the study group self-reported substantial internalizing mental symptoms not always recognized by parents, and not always obvious in adaptive function or performance at ADHD test. Correlations between BYI and FTF were low. The BYI depression inventory correlated negatively with VABS and positively with activity level in a subgroup medicated for ADHD. There was a stronger correlation between girls BYI and FTF results as compared with boys.

CONCLUSIONS

The results highlight the need for identification of anxiety and depression, using both self- and parent report. Present anxiety and depression symptoms do not seem to affect the clinical assessment of ASD and ADHD.

Preschool to School in Autism: Neuropsychiatric Problems 8 Years After Diagnosis at 3 Years of Age

The study presents neuropsychiatric profiles of children aged 11 with autism spectrum disorder, assessed before 4.5 years, and after interventions. The original group comprised a community sample of 208 children with ASD. Parents of 128 participated-34 with average intellectual function, 36 with borderline intellectual function and 58 with intellectual disability. They were interviewed using the Autism-Tics, AD/HD and other Comorbidities interview. Criteria for a clinical/subclinical proxy of ASD were met by 71, 89 and 95 %, respectively. Criteria for at least one of ASD, AD/HD, Learning disorder or Developmental Coordination Disorder were met by 82, 94 and 97 %. More than 90 % of children with a preschool diagnosis of ASD have remaining neuropsychiatric problems at 11, despite early intervention.

Asperger Syndrome and Schizophrenia: A Comparative Neuropsychological Study

There has been an increasing interest in possible connections between autism spectrum disorder (ASD) and schizophrenia in the last decade. Neuropsychological comparison studies have, however, been few. The present study examined similarities and differences in intellectual and executive functioning between adults with Asperger syndrome (AS) and adults with schizophrenic psychosis (SP). A group with AS and a group with SP were assessed neuropsychologically with WAIS-III and D-KEFS. Similarities were found between groups, as displayed by an uneven cognitive profile, limitations in working memory, processing speed and some aspects of executive functioning. Full Scale IQ was higher in the AS group. These results add to the current research illuminating similarities and differences between ASD and schizophrenia on a cognitive level.

[Organisation of health care for families with young children with autism in a multiethnic community in Gothenburg, Sweden]

Organisation of health care for families with young children with autism in a multiethnic community in Gothenburg, Sweden In a project in a multiethnic district in Gothenburg a local collaborative model with a multiprofessional team for families with young children with autism has been running for three years. The model allows assessments and intervention planning close to the family's local environment. The project has revealed that the time from identification of problems to assessment and intervention has been considerably shortened compared to the situation before the local collaborative model was started.

Parent- and Teacher-Reported Symptoms of ADHD in School-Aged Children With Active Epilepsy: A Population-Based Study

OBJECTIVE

Provide data on the distribution of parent- and teacher-reported symptoms of ADHD in childhood epilepsy and describe coexisting cognitive and behavioral disorders in children with both epilepsy and ADHD.

METHOD

Eighty-five (74% of those eligible) children (5-15 years) in a population-based sample with active epilepsy underwent psychological assessment. The ADHD Rating Scale-IV (ADHD-RS-IV) scale was completed by parents ( n = 69) and teachers ( n = 67) of participating children with an IQ > 34. ADHD was diagnosed with respect to Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.).

RESULTS

Parents reported significantly more symptoms of ADHD than teachers ( p < .001). Symptoms of inattention were more commonly reported than symptoms of hyperactivity-impulsivity ( p < .001). Neurobehavioral comorbidity was similar in those with ADHD and non-ADHD with the exception of oppositional defiant disorder (ODD) and developmental coordination disorder (DCD), which were more common in those with both epilepsy and ADHD.

CONCLUSION

Symptoms of ADHD are very common in childhood epilepsy but prevalence is influenced by informant.

Febrile Seizures and Epilepsy: Association With Autism and Other Neurodevelopmental Disorders in the Child and Adolescent Twin Study in Sweden

BACKGROUND

There is a recently well-documented association between childhood epilepsy and earlysymptomaticsyndromeselicitingneurodevelopmentalclinicalexaminations (ESSENCE) including autism spectrum disorder, but the relationship between febrile seizures and ESSENCE is less clear.

METHODS

The Child and Adolescent Twin Study in Sweden (CATSS) is an ongoing population-based study targeting twins born in Sweden since July 1, 1992. Parents of 27,092 twins were interviewed using a validated DSM-IV-based interview for ESSENCE, in connection with the twins' ninth or twelfth birthday. Diagnoses of febrile seizures (n = 492) and epilepsy (n = 282) were based on data from the Swedish National Patient Register. Prevalence of ESSENCE in individuals with febrile seizures and epilepsy was compared with prevalence in the twin population without seizures. The association between febrile seizures and ESSENCE was considered before and after adjustment for epilepsy. Age of diagnosis of febrile seizures and epilepsy was considered as a possible correlate of ESSENCE in febrile seizures and epilepsy.

RESULTS

The rate of ESSENCE in febrile seizures and epilepsy was significantly higher than in the total population without seizures (all P < 0.001). After adjusting for epilepsy, a significant association between febrile seizures and autism spectrum disorder, developmental coordination disorder, and intellectual disability remained. Earlier age of onset was associated with all ESSENCE except attention-deficit/hyperactivity disorder in epilepsy but not with ESSENCE in febrile seizures.

CONCLUSIONS

In a nationally representative sample of twins, there was an increased rate of ESSENCE in childhood epilepsy and in febrile seizures. Febrile seizures alone could occur as a marker for a broader ESSENCE phenotype.

Premorbid BMI predicts binge-purge symptomatology among individuals with anorexia nervosa

OBJECTIVE

A finding consistent with the transdiagnostic approach to eating disorders is that about half of those with restricting anorexia nervosa (AN) eventually undergo a transition to the binge/purge (BP) subtype or to bulimia nervosa. Given evidence that individuals with bulimic symptoms exhibit elevated weights premorbidly, we tested the hypothesis that among those with AN, highest premorbid BMI would predict which individuals with AN would develop AN-BP.

METHOD

The current study used longitudinal data from a community sample of adolescents with AN in Sweden. Premorbid weights were obtained from growth charts, and participants were re-assessed at 6, 10, and 18 years after first presentation with AN.

RESULTS

A greater highest premorbid BMI z score predicted a greater likelihood of developing binge/purge symptoms over 18 years.

DISCUSSION

Among individuals who develop an eating disorder, premorbid BMI may be implicated in the type and course of the eating disorder that emerges.

The role of cholesterol metabolism and various steroid abnormalities in autism spectrum disorders: A hypothesis paper

Based on evidence from the relevant research literature, we present a hypothesis that there may be a link between cholesterol, vitamin D, and steroid hormones which subsequently impacts on the development of at least some of the "autisms" [Coleman & Gillberg]. Our hypothesis, driven by the peer reviewed literature, posits that there may be links between cholesterol metabolism, which we will refer to as "steroid metabolism" and findings of steroid abnormalities of various kinds (cortisol, testosterone, estrogens, progesterone, vitamin D) in autism spectrum disorder (ASD). Further research investigating these potential links is warranted to further our understanding of the biological mechanisms underlying ASD. Autism Res 2017. © 2017 The Authors Autism Research published by Wiley Periodicals, Inc. on behalf of International Society for Autism Research. Autism Res 2017, 10: 1022-1044. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

Maltreatment-associated neurodevelopmental disorders: a co-twin control analysis

BACKGROUND

Childhood maltreatment (CM) is strongly associated with psychiatric disorders in childhood and adulthood. Previous findings suggest that the association between CM and psychiatric disorders is partly causal and partly due to familial confounding, but few studies have investigated the mechanisms behind the association between CM and neurodevelopmental disorders (NDDs). Our objective was to determine whether maltreated children have an elevated number of NDDs and whether CM is a risk factor for an increased NDD 'load' and increased NDD symptoms when controlling for familial effects.

METHODS

We used a cross-sectional sample from a population-representative Swedish twin study, comprising 8,192 nine-year-old twins born in Sweden between 1997 and 2005. CM was defined as parent-reported exposure to emotional abuse/neglect, physical neglect, physical abuse, and/or sexual abuse. Four NDDs were measured with the Autism-Tics, AD/HD, and other comorbidities inventory.

RESULTS

Maltreated children had a greater mean number of NDDs than nonmaltreated children. In a co-twin control design, CM-discordant monozygotic twins did not differ significantly for their number of NDDs, suggesting that CM is not associated with an increased load of NDDs when genetic and shared environmental factors are taken into account. However, CM was associated with a small increase in symptoms of attention-deficit/hyperactivity disorder and autism spectrum disorder in CM-discordant MZ twins, although most of the covariance of CM with NDD symptoms was explained by common genetic effects.

CONCLUSIONS

Maltreated children are at higher risk of having multiple NDDs. Our findings are, however, not consistent with the notion that CM causes the increased NDD load in maltreated children. Maltreated children should receive a full neurodevelopmental assessment, and clinicians should be aware that children with multiple NDDs are at higher risk of maltreatment.