Validity of the ESSENCE-Q neurodevelopmental screening tool in Japan.

AIM: To assess the validity of the Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations-Questionnaire (ESSENCE-Q), a simple screening tool for neurodevelopmental problems, in Japan. METHOD: Parents/caregivers completed the 11-item ESSENCE-Q for 77 612 children aged 2 years 6 months included in a national birth cohort study. Information about neurodevelopmental disorders (NDDs: autism spectrum disorder; intellectual disability and/or developmental language disorder; motor delay/motor disorder) was collected at age 3 years. Each ESSENCE-Q item was scored on a binary (0,1) scale, with a total score range of 0 to 11. Total scores and individual items were compared across children with and without NDDs. RESULTS: NDDs were recorded in 854 children (1.1%). With a total ESSENCE-Q score cut-off of ≥3, receiver operating characteristic curve analysis showed an area under the curve of 0.91, with sensitivity 84.9%, specificity 84.8%, positive predictive value 5.9%, and negative predictive value 99.8%. The proportion of parental concerns at 2 years 6 months differed significantly by NDD status for communication (89.5% vs 14.2%) and general development (80.2% vs 7.4%). ESSENCE-Q total scores were moderately negatively correlated (-0.36, p < 0.001) with Japanese Ages and Stages Questionnaire scores. INTERPRETATION: The parent/caregiver-completed ESSENCE-Q is useful as a tool for screening out children with neurotypical development at this early age. Further research into longer-term predictive validity will be possible as more NDD diagnoses are given as the children grow up.

The ESSENCE-Q: Can specialist supervision improve scoring agreement across specialist and public health nurses/nursery teachers?

AIM: This study aimed to explore whether the supervision of community public health nurses (PHNs) and nursery school teachers (NSTs) by a specialist, familiar with Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations (ESSENCE), improved the agreement of ESSENCE-Questionnaire (ESSENCE-Q) scoring, across raters. METHODS: A PHN, two NSTs, and a speech-language pathologist (SLP), familiar with ESSENCE, independently assessed 32 children. The ESSENCE-Q results were divided into the first (child 1-18) and second groups (the 19th child and the following children). Changes in score discrepancies were analysed for ESSENCE-Q cutoff scores and total ESSENCE-Q scores across raters. The SLP scores were used as a reference to evaluate sensitivity and specificity. RESULTS: The total ESSENCE-Q scores of the PHN and NSTs showed higher concordance in the second group (p < 0.05). Comparisons of the differences between the PHN/NSTs and SLP in total ESSENCE-Q scores showed a significantly smaller difference in the NSTs' scores in the second group (p < 0.05). CONCLUSION: The findings suggest that specialist supervision may lead to a better agreement between PHN and NSTs regarding ESSENCE-Q scores.

Vitamin D deficiency associated with neurodevelopmental problems in 2-year-old Japanese boys.

AIM: While associations between vitamin D deficiency and neurodevelopmental disorders have been found, large studies on child vitamin D, neurodevelopment, and sex differences among the general population are lacking. This study aimed to investigate the association between child serum 25-hydroxyvitamin D (25(OH)D)) levels and neurodevelopmental problems (NDPs). METHODS: Serum 25(OH)D and NDPs were measured at age two among the subcohort study of the Japan Environment and Children's Study. NDPs were assessed with the Kyoto Scale of Psychological Development 2001 (Kyoto scale). Adjusted odds ratios (aORs) for the Kyoto-scale developmental quotient scores <70 were calculated, for postural-motor, cognitive-adaptive, and language-social domains and overall scores, adjusted for test month, latitude, small for gestational age, maternal age, and daycare attendance. RESULTS: Among 2363 boys and 2290 girls, boys had higher 25(OH)D levels, but scored lower in the Kyoto scale. For boys in the vitamin D deficiency (<20 ng/mL) group, aORs of scoring the Kyoto-scale DQs <70 were 2.33 (p = 0.006) for overall DQs, 1.91 (p = 0.037) for cognitive-adaptive, and 1.69 (p = 0.024) for language-social domains. For girls, results were inconclusive. CONCLUSION: Only boys showed a clear and cross-modal association between vitamin D deficiency and NDPs.

Inability to start or complete upper secondary school strongly predicts unemployment and psychosocial and psychiatric adversities - A register-based follow-up study from southwestern Sweden.

AIM: To study academic, social and psychiatric outcomes among adults in the general population in southwestern Sweden. Groups of individuals born in 1998 and ineligible, eligible but not completed, and eligible and completed upper secondary school were followed in 2020. METHODS: Data were retrieved from Statistics Sweden, the Swedish National Agency for Education, the Longitudinal Integrated Database for Health Insurance and Labour Market Studies, the Swedish National Crime Register and the National Patient Register. The four adverse outcomes neither engaging in post-secondary studies nor having a regular salary, needing social benefits, having any criminal conviction, and having a psychiatric disorder at age ≥16 were examined. RESULTS: Of the final sample of 2706 individuals who had attended 9th grade of compulsory school in 2014, 273 (10%) were ineligible for upper secondary school. Of eligible individuals, 82 (3%) never started, 282 (10%) did not complete and 2065 (77%) completed upper secondary school. Compared with completers, the odds ratios for adverse outcomes were markedly increased for all other groups up to 22 years old. CONCLUSION: Inability to start or complete upper secondary school strongly predicted unemployment and psychosocial and psychiatric adversities. School authorities should consider offering vocational programmes post compulsory school without grade restrictions.

Neurodevelopmental problems, general health and academic achievements in a school-based cohort of 11-year-old Swedish children.

AIM: Assessing rates of neurodevelopmental problems (NDPs) in 11-year-old children and possible association with other health complaints and school performance. METHODS: In-school study of 11-year-old children as an add-on assessment to the 4th grade regular health check-up, comprising a structured physical neurodevelopmental examination, neuropsychological assessment, behavioural ratings, maternal interview, review of medical records and academic achievements. RESULTS: Out of 348 children recruited from eight schools, 223 (64%) participated. Any physical condition was found in 102/222 (46%), most commonly atopy (18%). One in five had a BMI z-score >2 standard deviations over the reference mean. One or more NDP was found in 86/221 (40%) children. The number of failed national tests correlated positively with NDP severity rated with the clinical global impression severity instrument (Spearman's r = 0.41, p < 0.001). The majority of participants with failed national tests, also had co-occurring health complaints (≥2 of: stomach or extremity ache, headache, difficulties sleeping, internalising symptoms or obesity) and NDPs. CONCLUSION: Health complaints, physical conditions and NDPs are very common in 11-year-old children and warrant adequately staffed, thoroughly equipped school healthcare services.

Mental and physical health in children of women with a history of anorexia nervosa.

Few studies have investigated the offspring of women with anorexia nervosa (AN). The aim of this study was to examine perinatal status, mental and physical health in the offspring of mothers with a history of AN. Fifty-one individuals with adolescent-onset AN and 51 matched controls (COMP) have been followed prospectively. Presently, 30 years after AN onset, at a mean age of 44 years, female participants who had given birth (nAN = 40, nCOMP = 40) were interviewed regarding psychiatric health in their offspring using the Developmental and Well-Being Assessment and the MINI International Neuropsychiatric Interview. In addition, information on the offspring's perinatal status, psychiatric- and physical health was obtained from the Swedish Medical Birth Register and The Swedish National Patient Register. Data regarding mental and physical health were available for 83 and 86 offspring in the AN and COMP groups, respectively. At birth, all of weight, length, head circumference and ponderal index were significantly reduced in the offspring of mothers with a history of AN. In adolescence, parental interviews indicated an overrepresentation of current psychiatric diagnoses in the offspring of mothers with AN. Compared with the offspring in the COMP group, endocrinological, immune and metabolic disorders were much more common in the offspring of the AN group. In conclusion, a history of AN increases the risk of worse perinatal outcome of the offspring. Later on, in childhood and adolescence, psychiatric and physical morbidity may be overrepresented in the offspring of women with AN.

Neurodevelopmental and other psychiatric disorders in 22q11.2 deletion syndrome from childhood to adult age: Prospective longitudinal study of 100 individuals.

The 22q11.2 deletion syndrome (22q11.2DS), affects physical as well as cognitive and emotional functioning with increased risk for psychiatric and behavioral problems. This longitudinal study of 79 individuals (18-50 years) with 22q11.2DS investigated neurodevelopmental (NDD) and psychiatric disorders in adulthood, evaluated the stability of childhood diagnoses over time, and examined associations between clinical characteristics in childhood/adolescence and diagnostic outcome in adult age. Examination using validated instruments for cognitive, psychiatric, and global functional problems in the context of an in-depth clinical evaluation found adult age stability of NDD diagnoses made in childhood, however, rates increased at follow-up. Rates of anxiety, mood, and psychotic disorders were high, with a majority meeting diagnostic criteria for one or more psychiatric disorder. The rate of psychotic disorders was much lower compared to many other studies. Variability in functioning at follow-up was primarily associated with intellectual ability at T1. The findings obtained highlight the increased risk of NDD and psychiatric problems and of cognitive impairment and reduced levels of global functioning over time. Results emphasize the importance of clinical follow-up to enable appropriate support for the promotion of optimal health along with a need for future research on effective interventions and treatment strategies.

Evaluation of C4 Gene Copy Number in Pediatric Acute Neuropsychiatric Syndrome.

Pediatric acute-onset neuropsychiatric syndrome (PANS) is an abrupt-onset neuropsychiatric disorder. PANS patients have an increased prevalence of comorbid autoimmune illness, most commonly arthritis. In addition, an estimated one-third of PANS patients present with low serum C4 protein, suggesting decreased production or increased consumption of C4 protein. To test the possibility that copy number (CN) variation contributes to risk of PANS illness, we compared mean total C4A and total C4B CN in ethnically matched subjects from PANS DNA samples and controls (192 cases and 182 controls). Longitudinal data from the Stanford PANS cohort (n = 121) were used to assess whether the time to juvenile idiopathic arthritis (JIA) or autoimmune disease (AI) onset was a function of total C4A or C4B CN. Lastly, we performed several hypothesis-generating analyses to explore the correlation between individual C4 gene variants, sex, specific genotypes, and age of PANS onset. Although the mean total C4A or C4B CN did not differ in PANS compared to controls, PANS patients with low C4B CN were at increased risk for subsequent JIA diagnosis (hazard ratio = 2.7, p value = 0.004). We also observed a possible increase in risk for AI in PANS patients and a possible correlation between lower C4B and PANS age of onset. An association between rheumatoid arthritis and low C4B CN has been reported previously. However, patients with PANS develop different types of JIA: enthesitis-related arthritis, spondyloarthritis, and psoriatic arthritis. This suggests that C4B plays a role that spans these arthritis types.

A novel tablet-based motor coordination test performs on par with the Beery VMI subtest and offers superior temporal metrics: findings from children with pediatric acute-onset neuropsychiatric syndrome.

Neuropsychiatric and neurodevelopmental disorders are often associated with coordination problems. Pediatric Acute-onset Neuropsychiatric Syndrome (PANS) constitutes a specific example of acute and complex symptomatology that includes difficulties with motor control. The present proof-of-concept study aimed at testing a new, bespoke tablet-based motor coordination test named SpaceSwipe, providing fine-grained measures that could be used to follow-up on symptoms evolution in PANS. This test enables computationally precise and objective metrics of motor coordination, taking into account both directional and spatial features continuously. We used SpaceSwipe to assess motor coordination in a group of children with PANS (n = 12, assessed on in total of 40 occasions) and compared it against the motor coordination subtest from the Beery-Buktenica Developmental Test of Visual-Motor Integration (Beery VMI) 6th edition, traditionally used to follow-up symptomatology. Using a bivariate linear regression, we found that 33 s of the directional offset from tracking a moving target in SpaceSwipe could predict the Beery VMI motor coordination (VMI MC) raw scores (mean absolute error: 1.75 points). Positive correlations between the predicted scores and the VMI MC scores were found for initial testing (radj = 0.87) and for repeated testing (radj = 0.79). With its short administration time and its close prediction to Beery VMI scores, this proof-of-concept study demonstrates the potential for SpaceSwipe as a patient-friendly tool for precise, objective assessment of motor coordination in children with neurodevelopmental or neuropsychiatric disorders.

A randomized controlled trial of a new intervention in early symptomatic syndromes eliciting neurodevelopmental clinical examinations: PR-ESSENCE.

The need for effective intervention programs for youth with neurodevelopmental problems (ESSENCE) and challenging behaviour is great. This study examines Problem Resolution in ESSENCE (PR-ESSENCE), a newly developed model in which children and parents develop mutual problem resolution strategies. Ten-week randomized controlled trial of PR-ESSENCE for children and adolescents aged 5-18 years, compared to treatment as usual. Outcomes were assessed at baseline and randomized period endpoint. Primary outcome was the Clinical Global Impression-Improvement scale (CGI-I) rated by blinded assessors. Secondary outcomes were rated by parents-SNAP-IV, Eyberg Child Behavior Inventory (ECBI), Relationship Problems Questionnaire, Family Burden of Illness Module, and children-Beck Youth Inventories (BYI). ClinicalTrials.gov identifier: NCT03780413. The study enrolled 108 participants (active n = 72; controls n = 36, randomized 2:1), of whom 95 completed the randomized period. No clinically significant group differences were found in baseline characteristics. More than half had autism and 80% had ADD or ADHD. Large treatment effects were seen on CGI-I (ITT analysis, Effect Size 1.48). Treatment responders, much/very much improved on CGI-I, were 51.4% in active group and 5.6% of controls. Effect sizes were medium to large in parent ratings on SNAP-IV (ODD and ADHD symptoms), ECBI (behaviour problems), and in BYI child self-ratings of disruptive behaviour. PR-ESSENCE treatment improved global symptoms and functioning (CGI-I), behaviour problems, ADHD and ODD symptoms, and disruptive behaviour. Treatment effects were at least equivalent to those in previous studies of well-established Parent Management Training and Collaborative Problem Solving programs.

Perceived child impairment and the 'autism epidemic'.

BACKGROUND: The prevalence of diagnosed Autism Spectrum Disorder (ASD) has increased substantially across the world. Much - or even most - prevalence increase seems to reflect changes in diagnostic practice and ascertainment. A key part of ASD assessment is to document that the relevant symptoms are associated with clinical impairment. The aim of the present study is to capitalize on a nationwide longitudinal study spanning 15 consecutive birth year cohorts in order to investigate whether there has been a secular change in how parents perceive the impairment and suffering conferred by autism symptomatology in their children. METHODS: Data came from the Child and Adolescent Twin Study in Sweden (27,240 individuals), where parents had reported on their child's ASD symptoms and impairment. Impairment due to ASD symptoms was regressed on an ASD symptom score across time. This was done for five 3-year birth cohorts (1995-1997, 1998-2000, 2001-2003, 2004-2006, and 2007-2009). RESULTS: Reported impairment increased with consecutively later birth cohorts. This was evident across all levels of autism symptomatology. At clinically relevant levels of symptomatology, parents of those born 2007-2009 reported a 23% higher degree of impairment as compared with parents of those born in 1995-1997. The relative difference, however, was even greater at levels that previously would have been considered below the diagnostic threshold. DISCUSSION: The results presented here contribute to the notion of a growing diffuseness in the conceptualization of the ASD diagnosis by adding the element of secular changes in the parental perception of the consequences of ASD symptom expression.

Neuroimaging findings in children with cerebral palsy with autism and/or attention-deficit/hyperactivity disorder: a population-based study.

AIM: To compare neuroimaging patterns according to the Magnetic Resonance Imaging Classification System (MRICS) in children with cerebral palsy (CP) with and without autism and/or attention-deficit/hyperactivity disorder (ADHD). METHOD: This population-based study assessed 184 children (97 males, 87 females) with CP born from 1999 to 2006 from the CP register of western Sweden, who had completed comprehensive screening and clinical assessment for neuropsychiatric disorders and undergone neuroimaging. RESULTS: Autism (total prevalence 30%) and ADHD (31%) were common in all neuroimaging patterns, including normal. Autism and ADHD were not more prevalent in children with bilateral than unilateral lesions, contrary to other associated impairments. Children with predominant white matter injury, related to insults in the late second or early third trimester, had the highest prevalence of autism (40%). Children who had sustained a middle cerebral artery infarction had the highest prevalence of ADHD (62%). INTERPRETATION: Although autism and ADHD are common regardless of neuroimaging patterns, timing and localization of insult appear to be of importance for the occurrence of autism and ADHD in children with CP. Neuroimaging may be of prognostic value for these associated impairments. Further in-depth neuroimaging studies may lead to a better understanding of the association between CP and neuropsychiatric disorders.

Internalizing symptoms in adolescence are modestly affected by symptoms of anxiety, depression, and neurodevelopmental disorders in childhood.

BACKGROUND: Internalizing disorders, such as anxiety and depressive disorders, are common mental disorders in young people, but a detailed understanding of the symptom continuity from childhood to adolescence that additionally includes a variety of neurodevelopmental disorder (NDD) symptoms is lacking. We therefore aimed to assess the extent to which parent-reported anxiety, depression, and NDD symptoms in childhood predict parent-reported internalizing symptoms in adolescence. METHODS: We used the nation-wide population-based Child and Adolescent Twin Study in Sweden, comprising 4492 twins born in Sweden between 1998 and 2003 that were assessed at age 9, and then again at age 15. Linear regression in a structural equation modelling framework was used to analyze the data. RESULTS: Overall, our results indicate that 15.9% of the variance in internalizing symptoms at age 15 can be predicted by anxiety, depression, and NDD symptoms at age 9. Anxiety and NDD symptoms in childhood predicted the largest amount of internalizing symptoms in adolescence. CONCLUSIONS: Adolescent internalizing symptoms are modestly affected by childhood symptoms of anxiety, depression, and NDDs, suggesting that they may represent different constructs across age. Future studies should further empirically investigate differences in etiology and trajectories of childhood versus adolescent internalizing symptoms.

Paediatric Acute-onset Neuropsychiatric Syndrome (PANS) and intravenous immunoglobulin (IVIG): comprehensive open-label trial in ten children.

BACKGROUND: Treatment with intravenous immunoglobulin (IVIG) in children with Paediatric Acute-onset Neuropsychiatric Syndrome (PANS) has for many years been used on clinical indications, but the research evidence for its efficacy is insufficient. METHODS: Open-label prospective in-depth trial including ten children (median age 10.3 years) with PANS, who received IVIG treatment 2 g/kg monthly for three months. Primary outcomes were changes in symptom severity and impairment from baseline to first and second follow-up visits one month after first and one month after third treatment, using three investigator-rated scales: Paediatric Acute Neuropsychiatric Symptom (PANS) scale, Clinical Global Impression - Severity and Improvement (CGI-S and CGI-I) scales. Secondary outcomes reported here were changes in Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS) scores, and side effects. RESULTS: All ten children received three treatments at one-month intervals according to study plan. From baseline to second follow-up marked reductions were seen in mean total PANS scale scores (p = .005), and CGI-S scores (p = .004). CGI-I ratings showed much to very much global improvement (mean CGI-I 1.8). Nine children had clinical response defined as > 30% reduction in PANS Scale scores. Improvements were also noted for CY-BOCS scores (p = .005), and in school attendance. Three children suffered moderate to severe temporary side effects after the first treatment, and the remaining seven had mild to moderate side effects. Side effects were much less severe after second and third treatments. CONCLUSIONS: Considerable and pervasive improvements in symptoms and clinical impairments were seen in these ten children after three monthly IVIG treatments. Moderate to severe transient side effects occurred in three cases. TRIAL REGISTRATION: EudraCT no. 2019-004758-27, Clinicaltrials.gov no. NCT04609761, 05/10/2020.

Neurodevelopmental problems in children with febrile seizures followed to young school age: A prospective longitudinal community-based study in Sweden.

AIM: To estimate the accumulated prevalence of neurodevelopmental problems from preschool to school age in children with a history of febrile seizures (FS). METHODS: In a community-based cohort of children with previous FS, 25/73 clinically assessed children met diagnostic criteria for neurodevelopmental disorders or had major indications of such problems at the age of 4-5 years. Parents of 54 of the 73 children accepted to take part in an interview according to the Autism-Tics, ADHD and other Comorbidities (A-TAC) inventory, when the children were 9-10 years. RESULTS: There was a trend for ADHD symptom scores to be higher in the FS group. Non-participants at age 9-10 years had had much higher rates of neurodevelopmental problems at 4-5 years, and the total number of such problems at either 4-5 or age 9-10 was 41% (30/73). CONCLUSION: High rates of neurodevelopmental problems (41%) were found at either age 4-5 or 9-10 years or both in this group of 73 children with FS. Non-participants at 9-10 years had had much higher rates of neurodevelopmental problems at 4-5 years. Further follow-up of this cohort is needed before definite conclusions can be drawn about whether FS should be considered a marker for more complex neurodevelopmental problems.

Neurodevelopmental problems and quality of life in 6-year-olds with a history of developmental language disorder.

AIM: To explore family-reported neurodevelopmental functioning and quality of life in 6-year-olds who had screened positive for developmental language disorder at age 2.5 years. METHODS: Parents of 85 6-year-old children completed questionnaires about child neurodevelopmental difficulties and quality of life. The children were interviewed regarding quality of life, and their language was assessed by speech and language pathologists. Test results at 6 years identified three subgroups: children with developmental language disorder (n = 68) or speech sound disorder (n = 6) and children with no current language disorder (n = 11). RESULTS: Out of the 68 children with developmental language disorder, 33 (48%) had significant parent-rated problems with language, executive functions 17 (25%), perception 15 (22%) and/or motor skills 15 (22%). Four (67%) of the children with speech sound disorder had significant problems with language. Significant problems were reported with language in five (45%) and with perception in four (36%) children with no current language disorder. The parents reported no impaired quality of life, whereas the children themselves reported impairment mainly with school functioning. CONCLUSIONS: Overlap between language difficulties and other neurodevelopmental problems was higher in 6-year-olds who had screened positive for developmental language disorder about 3 years earlier, than in the general population. The parent and child reports of quality of life were not consistent.

Paediatric Acute onset Neuropsychiatric Syndrome: Exploratory study finds no evidence of HLA class II association but high rate of autoimmunity in first-degree relatives.

AIM: Paediatric acute-onset neuropsychiatric syndrome (PANS) is defined by an acute onset of obsessive-compulsive disorder and/or eating restrictions and at least two other severe neuropsychiatric symptoms. The condition is suspected to have an immune-mediated pathophysiology, but reliable biomarkers have not been identified. METHODS: We hypothesised that PANS, like narcolepsy, might have a human leucocyte antigen (HLA) association, as found in 95% of children developing narcolepsy after H1N1 immunisation. Low resolution genotyping of the MHC class II antigens HLA-DRB1 and HLA-DQB1 was performed using two different PCR-based methods. In addition, parents were interviewed regarding a detailed family history of autoimmune diseases in first-degree relatives. A total of 18 children, aged 5-14 (mean 8.2) years at onset of PANS met symptom criteria. RESULTS: No evident association between PANS and the specific HLA alleles examined was observed. In first-degree relatives of 10 of the 18 children, an autoimmune disease had been diagnosed, and three of the 18 children themselves had an autoimmune disease. CONCLUSION: No HLA allele association such as seen in children with narcolepsy after H1N1 immunisation could be confirmed in this group of children with PANS. However, more than half the group had a first-degree relative with a diagnosed autoimmune disease.

Development of a parent-reported screening tool for avoidant/restrictive food intake disorder (ARFID): Initial validation and prevalence in 4-7-year-old Japanese children.

The prevalence of avoidant/restrictive food intake disorder (ARFID) in the general child population is still largely unknown and validated screening instruments are lacking. The aims of this study were (1) to investigate the prevalence of children screening positive for ARFID in a Japanese birth cohort using a newly developed parent-reported screening tool, (2) to estimate the prevalence of children with ARFID experiencing physical versus psychosocial consequences of their eating pattern, and (3) to provide preliminary evidence for the validity of the new screening tool. Data were collected from 3728 4-7-year-old children born between 2011 and 2014 in Kochi prefecture, Japan (response rate was 56.5%); a sub-sample of the Japan Environment and Children's Study (JECS). Parents completed a questionnaire including the ARFID screener and several other measures to assess convergent validity. The point prevalence of children screening positive for ARFID was 1.3%; half of them met criteria for ARFID based on psychosocial impairment alone, while the other half met diagnostic criteria relating to physical impairment (and additional psychosocial impairment in many cases). Sensory sensitivity to food characteristics (63%) and/or lack of interest in eating (51%) were the most prevalent drivers of food avoidance. Children screening positive for ARFID were lighter in weight and shorter in height, they showed more problem behaviors related to mealtimes and nutritional intake, and they were more often selective eaters and more responsive to satiety, which together provides preliminary support for the validity of the new screening tool. This is the largest screening study to date of ARFID in children up to 7 years. Future studies should examine the diagnostic validity of the new ARFID screener using clinically ascertained cases. Further research on ARFID prevalence in the general population is needed.

Association of etiological factors across the extreme end and continuous variation in disordered eating in female Swedish twins.

BACKGROUND: Accumulating evidence suggests that many psychiatric disorders etiologically represent the extreme end of dimensionally distributed features rather than distinct entities. The extent to which this applies to eating disorders (EDs) is unknown. METHODS: We investigated if there is similar etiology in (a) the continuous distribution of the Eating Disorder Inventory-2 (EDI-2), (b) the extremes of EDI-2 score, and (c) registered ED diagnoses, in 1481 female twin pairs at age 18 years (born 1992-1999). EDI-2 scores were self-reported at age 18. ED diagnoses were identified through the Swedish National Patient Register, parent-reported treatment and/or self-reported purging behavior of a frequency and duration consistent with DSM-IV criteria. We differentiated between anorexia nervosa (AN) and other EDs. RESULTS: The heritability of the EDI-2 score was 0.65 (95% CI 0.61-0.68). The group heritabilities in DeFries-Fulker extremes analyses were consistent over different percentile-based extreme groups [0.59 (95% CI 0.37-0.81) to 0.65 (95% CI 0.55-0.75)]. Similarly, the heritabilities in liability threshold models were consistent over different levels of severity. In joint categorical-continuous models, the twin-based genetic correlation was 0.52 (95% CI 0.39-0.65) between EDI-2 score and diagnoses of other EDs, and 0.26 (95% CI 0.08-0.42) between EDI-2 score and diagnoses of AN. The non-shared environmental correlations were 0.52 (95% CI 0.32-0.70) and 0.60 (95% CI 0.38-0.79), respectively. CONCLUSIONS: Our findings suggest that some EDs can partly be conceptualized as the extreme manifestation of continuously distributed ED features. AN, however, might be more distinctly genetically demarcated from ED features in the general population than other EDs.

Anorexia nervosa and autism: a prospective twin cohort study.

BACKGROUND: Anorexia nervosa (AN) and autism spectrum disorder (ASD) may be phenotypically and etiologically linked. However, due to the absence of prospective studies, it remains unclear whether the elevation of autistic traits in AN is evident in early childhood. Here, we prospectively investigated autistic traits before and after the first diagnosis of AN. METHODS: In a population-based sample of 5,987 individuals (52.4% female) from the Child and Adolescent Twin Study in Sweden, parents reported autistic traits at ages 9 and 18. AN and ASD diagnoses were retrieved from the Swedish National Patient Register. In addition, AN diagnoses were ascertained by parent-reported treatment for AN. We compared whether individuals with and without AN differed in autistic traits before the first diagnosis of AN (age 9) and after the first diagnosis of AN (age 18). RESULTS: We did not find evidence for elevated autistic traits in 9-year-old children later diagnosed with AN. At age 18, however, there was a marked elevation in restricted/repetitive behavior and interests, but only in the subgroup of individuals with acute AN. A less pronounced elevation was observed for social communication problems. CONCLUSIONS: Coping strategies in individuals with ASD and the somewhat different female ASD phenotype may explain why we did not find elevated autistic traits in children who later developed AN. Alternatively, it is possible that elevated autistic traits were not present prior to the onset of AN, thus questioning the previously reported elevated prevalence of ASD in AN. Future studies should use tailored measurements in order to investigate whether autistic traits in individuals with AN are best conceptualized as an epiphenomenon of the acute AN phase or whether these symptoms indeed represent ASD as a clinically verifiable neurodevelopmental disorder.