The implications of the COVID-19 pandemic on eating disorder features and comorbid psychopathology among adolescents with anorexia nervosa and matched controls: a comparative cohort design study.

PURPOSE: To examine implications of the COVID-19 pandemic on eating disorder (ED) features and psychopathology in female adolescents with anorexia nervosa (AN). METHOD: In total 79 females with first-onset AN (aged 12-22 years) were included and were followed up across a period of 1 year. We assessed AN participants recruited pre-pandemic (n = 49) to those recruited peri-pandemic (n = 30). Pre- (n = 37) and peri-pandemic (n = 38) age-, and education-matched typically developing (TD) girls (n = 75) were used as a reference cohort. ED features and psychopathology were assessed at baseline. After 1 year of follow-up the association between pandemic timing and clinical course was assessed. Analyses of covariance were used to examine differences in ED features and psychopathology. RESULTS: Peri-pandemic AN participants experienced less ED symptoms at baseline compared to pre-pandemic AN participants. In particular, they were less dissatisfied with their body shape, and experienced less interpersonal insecurity. In addition, the peri-pandemic AN group met fewer DSM-IV criteria for comorbid disorders, especially anxiety disorders. In contrast, peri-pandemic AN participants had a smaller BMI increase over time. In TD girls, there were no differences at baseline in ED features and psychopathology between the pre- and peri-pandemic group. CONCLUSION: Overall, peri-pandemic AN participants were less severely ill, compared to pre-pandemic AN participants, which may be explained by less social pressure and peer contact, and a more protective parenting style during the pandemic. Conversely, peri-pandemic AN participants had a less favorable clinical course, which may be explained by reduced access to health care facilities during the pandemic. LEVEL OF EVIDENCE: Level III: Evidence obtained from well-designed cohort or case-control analytic studies.

Children with Autism Spectrum Disorder in Times of COVID-19: Examining Emotional and Behavioral Problems, Parental Well-Being, and Resilience.

This longitudinal study assessed the impact of the COVID-19 pandemic on children with autism spectrum disorder (ASD; n = 62; Mage = 13 years) by measuring emotional and behavioral problems before and during the pandemic, and by comparing this change to a matched sample of children without ASD (n = 213; Mage = 16 years). Moreover, we examined whether indicators of parental well-being promoted resilience of children with ASD. Results showed that the mean change in problems did not differ between children with and without ASD. Importantly, some children showed an increase in problems, while others showed resilience. Parental well-being indicators were not related to resilience among children with ASD. The interindividual variability in responses, particularly among children with ASD, highlights the need for personalized support.

Associations between autism traits and family functioning over time in autistic and non-autistic children.

LAY ABSTRACT: Little is known about family functioning over time when raising a child with autism traits, with or without a clinical autism diagnosis. Therefore, we asked caregivers-mostly parents-of a group of 168 children about the family functioning and the child's emotional and behavioral characteristics, as well as autistic traits, twice with about 1 year in between. For numerous reasons, the children were referred to youth mental health care centers, including child and adolescent psychiatric services. Care as usual was offered after the diagnostic assessment if a clinical diagnosis was the assessment outcome. Caregivers reported less problematic family functioning in children with fewer autism traits over time. The child's additional emotional or behavioral characteristics did not seem to influence this relation. Furthermore, we split the whole group into autistic children with a clinical autism diagnosis (58%) and non-autistic children with autism traits but without a clinical diagnosis (42%) to see whether we would find the same results in both groups. Surprisingly, the relation between family functioning and the level of a child's autism traits only held for the subgroup of non-autistic children with autism traits. Thus, raising children with autism traits without a clinical diagnosis may affect family functioning over time. We think that families might have difficulty understanding and adjusting to the autism traits of their children but are lacking the support that is exclusively offered to families of children with a clinical autism diagnosis. We must be cautious because we do not know whether there is a causal relation. Although further research is needed to explore and learn to understand this result, clinicians might consider offering support to families of children with subthreshold autism to prevent problems in family functioning. Because high autism trait levels in non-autistic children may be of a different origin than autism, for example, other neurodevelopmental or mental health problems, family training or support should be tailored to the child's underlying difficulties.

An Explorative Study of Atypical Social Interaction Styles in Adult Men with Autism Spectrum Disorder, Men with Personality Disorders and Men from the General Population.

Different atypical social interaction styles (SISs) were defined and tested in children and adolescents with autism spectrum disorder (ASD). Whether these styles can also be distinguished in adults with ASD has not yet been explored. In men with ASD, men with personality disorder (PD), and men from the general population (N = 90), aged 18-65 years, we tested which SISs can be distinguished and how they relate to the presence of PD traits. We found a significant distinction in allocation to atypical SISs between the three groups. This study shows the presence of atypical SISs in adults with ASD, and complements previous SIS findings in children and adolescents with ASD.Trial registration The Netherlands National Trial Register NTR6391. Registered 04 May 2017.

Autism Symptoms in Children and Young Adults With Fragile X Syndrome, Angelman Syndrome, Tuberous Sclerosis Complex, and Neurofibromatosis Type 1: A Cross-Syndrome Comparison.

Objective: The etiology of autism spectrum disorder (ASD) remains unclear, due to genetic heterogeneity and heterogeneity in symptoms across individuals. This study compares ASD symptomatology between monogenetic syndromes with a high ASD prevalence, in order to reveal syndrome specific vulnerabilities and to clarify how genetic variations affect ASD symptom presentation. Methods: We assessed ASD symptom severity in children and young adults (aged 0-28 years) with Fragile X Syndrome (FXS, n = 60), Angelman Syndrome (AS, n = 91), Neurofibromatosis Type 1 (NF1, n = 279) and Tuberous Sclerosis Complex (TSC, n = 110), using the Autism Diagnostic Observation Schedule and Social Responsiveness Scale. Assessments were part of routine clinical care at the ENCORE expertise center in Rotterdam, the Netherlands. First, we compared the syndrome groups on the ASD classification prevalence and ASD severity scores. Then, we compared individuals in our syndrome groups with an ASD classification to a non-syndromic ASD group (nsASD, n = 335), on both ASD severity scores and ASD symptom profiles. Severity scores were compared using MANCOVAs with IQ and gender as covariates. Results: Overall, ASD severity scores were highest for the FXS group and lowest for the NF1 group. Compared to nsASD, individuals with an ASD classification in our syndrome groups showed less problems on the instruments' social domains. We found a relative strength in the AS group on the social cognition, communication and motivation domains and a relative challenge in creativity; a relative strength of the NF1 group on the restricted interests and repetitive behavior scale; and a relative challenge in the FXS and TSC groups on the restricted interests and repetitive behavior domain. Conclusion: The syndrome-specific strengths and challenges we found provide a frame of reference to evaluate an individual's symptoms relative to the larger syndromic population and to guide treatment decisions. Our findings support the need for personalized care and a dimensional, symptom-based diagnostic approach, in contrast to a dichotomous ASD diagnosis used as a prerequisite for access to healthcare services. Similarities in ASD symptom profiles between AS and FXS, and between NF1 and TSC may reflect similarities in their neurobiology. Deep phenotyping studies are required to link neurobiological markers to ASD symptomatology.

Impact of the COVID-19 pandemic on children and adolescents with autism spectrum disorder and their families: a mixed-methods study protocol.

BACKGROUND: The COVID-19 pandemic is a challenge for everyone, particularly for children and adolescents with autism spectrum disorder (ASD). ASD is a developmental disorder characterised by limitations in social communication, repetitive behavioural patterns, and limited interests, and activities. It is expected that many families with children with ASD will experience more problems due to the COVID-19 pandemic and the related public health restrictions. At the same time, some may experience improved functioning, due to fewer expectations and social demands. METHODS/DESIGN: In a mixed-method study to identify the impact of the COVID-19 pandemic, parents of children with ASD (ages 4-21) who were in care pre-COVID-19 at one of three large mental healthcare institutions in the region of Rotterdam participated (68 for T0, 57 for T1). The aims are (1) to investigate the impact of the COVID-19 pandemic on overall functioning and autistic symptoms of the child/adolescent with ASD, as well as parental and family functioning (QUANT-QUAL), in both the short term and longer term, and (2) to investigate risk and protective factors (in light of resilience) (QUANT-qual) and (3) to investigate care and informational needs (QUAL-quant). Pre-COVID-19 baseline data will be retrieved from clinical records. Participants will fill out two surveys (one during a COVID-19 peak-January-May 2021-and one thereafter). Survey participants were invited to participate in interviews (n=27). Surveys include measures thar were included pre-COVID-19 (ie, overall functioning and autism symptoms) as well as specific measures to identify family functioning and COVID-19 impact. The semistructured interviews focus on child, parent and family functioning and care-and informational needs. ETHICS AND DISSEMINATION: The Medical Ethics Committee of the Erasmus MC has approved the study. Findings will be available to families of children with ASD, their care providers, the funders, autism societies, the government and other researchers.

Caring for Children with an Autism Spectrum Disorder: Factors Associating with Health- and Care-Related Quality of Life of the Caregivers.

This study investigated the association of child, caregiver, and caregiving measurements with the quality of life (QoL) in 81 caregivers (mostly parents) of clinically referred children with autism spectrum disorder (ASD). We used the EuroQol five-dimensional (EQ-5D) questionnaire and the care-related QoL questionnaire (CarerQol) to respectively assess health-related QoL and care-related QoL. Health-related QoL was associated with the caregiver's internalizing problems and adaptive coping, explaining 38% of the variance. Parenting stress and adaptive coping were associated with the care-related QoL and explained 60% of the variance. Child variables were not associated with the caregiver's health- and care-related QoL if caregiver and caregiving variables were taken into account. Findings indicate the importance of the caregiver's mental health, coping, and parenting stress in caring for children with ASD.

Children with an Autism Spectrum Disorder and Their Caregivers: Capturing Health-Related and Care-Related Quality of Life.

This study investigated health-related QoL (HRQoL) and care-related quality of life (CarerQol) in clinically referred children with an autism spectrum disorder (ASD), and their primary and secondary caregivers. The EuroQol five-dimensional (EQ-5D) and the CarerQol questionnaires were used to respectively measure health-related QoL and care-related QoL. Primary caregivers reported pain/discomfort (42%) and anxiety/depression (40%). In caring, they mostly experienced problems in the relationship with the child (84%), and in combining care with daily activities (51%). Children with ASD had a relevantly lower QoL. Despite negative effects, almost all caregivers (96%) derived fulfillment from caring for their affected children. HRQoL and CarerQol reports of primary caregivers and children were correlated, both providing useful information to ASD measurement and treatment.

Emotional and behavioral problems in children with dilated cardiomyopathy.

BACKGROUND: Dilated cardiomyopathy (DCM) in children is an important cause of severe heart failure and carries a poor prognosis. Adults with heart failure are at increased risk of anxiety and depression and such symptoms predict adverse clinical outcomes such as mortality. In children with DCM, studies examining these associations are scarce. AIMS: We studied whether in children with DCM: (1) the level of emotional and behavioral problems was increased as compared to normative data, and (2) depressive and anxiety problems were associated with the combined risk of death or cardiac transplantation. METHODS: To assess emotional and behavioral problems in children with DCM, parents of 68 children, aged 1.5-18 years (6.9±5.7 years), completed the Child Behavior Checklist. RESULTS: Compared to normative data, more young children (1.5-5 years) with DCM had somatic complaints (24.3% vs. 8.0%; p < .001), but fewer had externalizing problems (5.4% vs. 17.0%; p = .049). Overall internalizing problems did not reach significance. Compared to normative data, more older children (6-18 years) showed internalizing problems (38.7% vs. 17.0%; p = .001), including depressive (29.0% vs. 8.0%; p < .001) and anxiety problems (19.4% vs. 8.0%; p = .023), and somatic complaints (29.0% vs. 8.0%; p < .001). Anxiety and depressive problems, corrected for heart failure severity, did not predict the risk of death or cardiac transplantation. CONCLUSION: Children of 6 years and older showed more depressive and anxiety problems than the normative population. Moreover, in both age groups, somatic problems were common. No association with outcome could be demonstrated.

Systematic Review and Meta-analysis of Virtual Reality in Pediatrics: Effects on Pain and Anxiety.

BACKGROUND: Medical procedures often evoke pain and anxiety in pediatric patients. Virtual reality (VR) is a relatively new intervention that can be used to provide distraction during, or to prepare patients for, medical procedures. This meta-analysis is the first to collate evidence on the effectiveness of VR on reducing pain and anxiety in pediatric patients undergoing medical procedures. METHODS: On April 25, 2018, we searched EMBASE, MEDLINE, CENTRAL, PubMed, Web of Science, and PsycINFO with the keywords "VR," "children," and "adolescents." Studies that applied VR in a somatic setting with participants ≤21 years of age were included. VR was defined as a fully immersive 3-dimensional environment displayed in surround stereoscopic vision on a head-mounted display (HMD). We evaluated pain and anxiety outcomes during medical procedures in VR and standard care conditions. RESULTS: We identified 2889 citations, of which 17 met our inclusion criteria. VR was applied as distraction (n = 16) during venous access, dental, burn, or oncological care or as exposure (n = 1) before elective surgery under general anesthesia. The effect of VR was mostly studied in patients receiving burn care (n = 6). The overall weighted standardized mean difference (SMD) for VR was 1.30 (95% CI, 0.68-1.91) on patient-reported pain (based on 14 studies) and 1.32 (95% CI, 0.21-2.44) on patient-reported anxiety (based on 7 studies). The effect of VR on pediatric pain was also significant when observed by caregivers (SMD = 2.08; 95% CI, 0.55-3.61) or professionals (SMD = 3.02; 95% CI, 0.79-2.25). For anxiety, limited observer data were available. CONCLUSIONS: VR research in pediatrics has mainly focused on distraction. Large effect sizes indicate that VR is an effective distraction intervention to reduce pain and anxiety in pediatric patients undergoing a wide variety of medical procedures. However, further research on the effect of VR exposure as a preparation tool for medical procedures is needed because of the paucity of research into this field.

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.

Development of emotional and behavioral problems in neurofibromatosis type 1 during young childhood.

This retrospective longitudinal study in young children with neurofibromatosis type 1 (NF1) aimed to identify if, and how early problems in behavior, intelligence, and language development are associated with later behavioral problems. At the first assessment at preschool age, we evaluated language skills, intelligence, and emotional and behavioral problems as reported by parents. The second assessment at school-age we evaluated intelligence, and emotional and behavioral problems as reported by parents and teachers. Association of baseline assessments with secondary assessment was evaluated using multivariable linear regression analysis. Of the 61 patients (25 males, 36 females; mean age 4;5 years [SD 1;1 years]) with NF1 who had a first assessment, 38 children (21 males, 17 females; mean age 7;11 years [SD 2;1 years]) had a second assessment after a mean period of 3;5 years. Longitudinal data on behavioral problems were collected for 23 of these children. Intelligence and language development were not associated with internalizing problems. Parent-rated internalizing behavioral problems significantly increased with age in this subgroup. Baseline internalizing problems predicted later internalizing problems (adjusted R2 = 0.33, p = 0.003). The presence of these problems at pre-school age may be predictive of internalizing problems at a later age.

Motor problems in children with neurofibromatosis type 1.

BACKGROUND: Children with the neurogenetic disorder neurofibromatosis type 1 (NF1) often have problems with learning and behaviour. In both parent reports and neuropsychological assessment, motor problems are reported in approximately one third to one half of the children with NF1. Studies using broad motor performance test batteries with relatively large groups of children with NF1 are limited. The aim of this cross-sectional observational study was to describe the severity of motor problems in children with NF1 and to explore the predictive value of demographics, intelligence, and behavioural problems. METHODS: From 2002 to 2014, 69 children with NF1, aged 4 to 16 years (age = 9.5 ± 2.8 years; 29 girls) had a motor, psychological, and neurological evaluation in an NF1 expertise centre. Data were collected about (1) motor performance (M-ABC: Movement Assessment Battery for Children), (2) intelligence, and (3) emotional and behavioural problems as rated by parents. RESULTS: Sixty-one percent of these children scored within the clinical range of the M-ABC. In ordinal logistic regression analyses, motor problems were associated with symptoms of attention-deficit/hyperactivity disorder (ADHD), symptoms of autism spectrum disorder (ASD), and externalising behavioural problems. Motor outcome was not predicted by age, intelligence, scoliosis, hypotonia, nor hypermobility. CONCLUSIONS: Motor problems are among the most common comorbid developmental problems in children with NF1, and these problems do not diminish with age. Because of their impact on daily functioning, motor problems need to be specifically addressed in diagnosis, follow-up, and treatment of NF1.

Using the Child Behavior Checklist and the Teacher's Report Form for identification of children with autism spectrum disorders.

This study evaluated the ability of the Child Behavior Checklist and the Teacher's Report Form to identify children with autism spectrum disorders (ASD), using a sample of children with ASD (n = 458), referred children without ASD (n = 1109) and children from the general population (n = 999). A ten items ASD scale was constructed using half of the sample and the ability of this scale to discriminate between children with ASD and the other children was tested for the CBCL and the TRF separately and together in the other half of the sample. Using a cut-off score of 8 the combined CBCL/TRF ASD scale demonstrated high predictive values (NPV 95%, PPV 73%) in identifying children with ASD and children in the general population sample. This might be an acceptable percentage of false positives in general screening, considering the chance that these children might have other behavioural, emotional, and developmental problems which also need psychiatric evaluation. In the referred population, using a cut-off of 13, PPV was 49% and NPV was 85%. The high NPV indicates that in a referred population the scale is especially good at identifying children who do not need evaluation with a more ASD-specific instrument.

The association of quality of social relations, symptom severity and intelligence with anxiety in children with autism spectrum disorders.

Limited quality of social relations, milder symptom severity and higher intelligence were shown to account for higher anxiety levels in autism spectrum disorders. The current study replicated and extended earlier findings by combining these three determinants of anxiety in autism spectrum disorders in one study. The sample consisted of 134 school-aged children with autism spectrum disorders, of whom 58 (43%) had a co-morbid anxiety disorder according to the Diagnostic Interview Schedule for Children-Parent version. In this sample, we tested associations between these determinants and anxiety univariately and multivariately to clarify the unique contribution of all determinants. Since we hypothesized that the association between limited quality of social relations and anxiety would be amplified by low symptom severity and/or high intelligence, we additionally tested for moderating effects. We found that higher anxiety levels were associated with a lower quality of social relations and lower symptom severity. In this mainly high-functioning sample, intelligence was not related to anxiety levels. No moderation effects were found. Since lower quality of social relations and lower symptom severity are associated with higher anxiety levels in children with autism spectrum disorders, therapeutic interventions aimed at reducing anxiety in autism spectrum disorders should pay attention to improving social relations, and presumably children with a lower symptom severity could benefit most from such interventions.

Empirically based phenotypic profiles of children with pervasive developmental disorders: interpretation in the light of the DSM-5.

This study aimed to contribute to the Diagnostic and Statistical Manual (DSM) debates on the conceptualization of autism by investigating (1) whether empirically based distinct phenotypic profiles could be distinguished within a sample of mainly cognitively able children with pervasive developmental disorder (PDD), and (2) how profiles related to diagnoses and co-occurring behavioral and emotional problems. Six classes with distinct profiles were discerned. Three classes showed profiles not completely in line with the proposed DSM-5 conceptualization of autism. These classes included relatively many cognitively able individuals with PDD-not otherwise specified. However, profiles seemed to suit other diagnostic categories, such as social communication disorder. These alternative diagnoses could retain eligibility for services, and might adequately fit more specifically targeted interventions.

The association between formal thought disorder and finger print asymmetry in children with a psychiatric disorder: an exploratory study.

Dermatoglyphics are the ridge constellations found on the hand palms and foot soles that are permanently formed by the 24th week of pregnancy. Associations have been found between adult schizophrenia and irregularities and asymmetries in dermatoglyphics. Children have not been studied before. The aim of this study was to assess the association between formal thought disorder (FTD), as a possible forerunner of schizophrenia, in children and asymmetry or discordance (DISC) of the finger prints. 222 children, aged 6-14, from an outpatient department of child psychiatry participated. Finger prints were rated with the three-pattern system (whorls, loops or arches). FTD criteria were illogical thinking (ILL), loose associations (LA), incoherence (INC), and poverty of content of speech (POC), as rated by the clinician. When boys with and without DISC were compared, no differences in FTD were found. In contrast, however, girls with DISC showed significantly more FTD than girls without DISC, t (72) = -2.39, p = 0.02. Further, for boys, only total FTD was positively correlated with DISC of the middle finger, r = 0.20, p = 0.02. For girls, total FTD was positively correlated with DISC of the index finger: r = 0.30, p = 0.02; DISC of the middle finger: r = 0.27, p = 0.03; and with total DISC dichotomous: r = 0.27, p = 0.02. In addition, total DISC correlated positively with ILL: r = 0.31, p = 0.01; LA: r = 0.23, p = 0.05; INC: r = 0.30, p = 0.01; and total FTD: r = 0.31, p = 0.01. Overall, the existence of finger print discordance, as a possible marker of prenatal instability, was associated with the occurrence of FTD in girls.

High 3D:5D ratio: A possible correlate ofexternalizing and internalizing problems. An exploratory study

Background and Objectives: The second to fourth (2D:4D) digit ratio is asexually dimorphic trait which has been studied to examine the association between fetal hormones and a variety of behaviors. Lower 2D:4D ratios, suggestive of exposure to higher levels of prenatal testosterone, have been associated with male-linked disorders, whilehigher 2D:4D ratios, suggestive of exposure to weaker prenatal androgen action, have been associated with female-linked disorders. Past research has concentrated on the 2D:4D ratio, whereas the relationship between other ratios, such as the 3D:5D ratio, and psychopathology has not much been studied before. Therefore, the aim of this study was to assess the correlation between the 2D:4D and 3D:5D ratio, and internalizing as well asexternalizing symptoms, in a large non-clinical sample (143 boys, 150 girls) of white Caucasianchildren aged 7 to 13 years. Methods: Externalizing and internalizing symptoms were assessed with the Child Behavior Checklist (CBCL). Results: The 3D:5D ratio in boys and in girls was positively associated with scores on Externalizing Problems. Further, in girls only, the 3D:5D ratio was positively correlated toscores on Internalizing Problems. Conclusions: The 3D:5D ratio can be considered a correlate of externalizing and internalizing problems in children from the general population (AU)

Autistic features in girls from a psychiatric sample are strongly associated with a low 2D:4D ratio.

Autistic features such as deficits in social interactions and communication have been associated with a low 2D:4D ratio in normal children.This study assessed this association in a large sample of children with a variety of psychiatric disorders (n = 35 girls and n = 147 boys). Autistic features were assessed with a highly valid and reliable measure (Autism Diagnostic Observation Schedule-Generic). Correlations between the 2D:4D ratio and autistic features were computed separately for boys and girls. Some small negative correlations (r = -0.17 and r = -0.19) were found in the right hand for boys; however, particularly in girls, large negative correlations (r = -0.51 to r = -0.64) were found in the left hand. A low 2D:4D ratio in girls was highly predictive of the presence of autistic features. Thus, a low ratio could possibly be used as a diagnostic predictor in clinical practice.

Classes of disruptive behavior problems in referred adolescents.

BACKGROUND: Previous studies have found considerable overlap between attention/hyperactivity problems, aggressive/oppositional problems and delinquent/conduct problems in adolescents. SAMPLING AND METHODS: Mothers of 1,965 11- to 18-year-olds (1,116 boys, 849 girls), referred to mental health agencies, completed the Child Behavior Checklist (CBCL). Latent class analysis was conducted on the Attention Problems scale (representing problems with attention, impulsivity and hyperactivity), Aggressive Behavior and Rule-Breaking Behavior scales of the CBCL. RESULTS: Six latent classes were found. One of these classes contained individuals who suffered predominantly from attention problems and to a far lesser degree from aggressive or rule-breaking behaviors. The other 5 classes represented individuals with varying degrees of attention problems, aggressive behaviors and rule-breaking behaviors. CONCLUSIONS: Contrary to previous studies, the present study indicated that, in a large referred sample, problems with attention, impulsivity and hyperactivity can be considered as a diagnostic construct that should be distinguished from aggressive or rule-breaking behaviors. However, the present study did not support the existence of diagnostic classes constituted by individuals who primarily suffer from aggressive behaviors or rule-breaking behaviors, and not from attention problems or hyperactivity. Implications of these findings for future research and clinical practice are discussed. The value of the study was limited by the use of parent reports only.