High-dose vitamin D3 supplementation in pregnancy and risk of neurodevelopmental disorders in the children at age 10: A randomized clinical trial.

BACKGROUND: Vitamin D deficiency in pregnancy may increase the risk of autism and attention deficit hyperactivity disorder (ADHD). OBJECTIVE: The objective of this study was to estimate the effect of vitamin D3 supplementation in pregnancy on risk of autism and ADHD. DESIGN: This randomized clinical trial was part of the COpenhagen Prospective Study on Neuro-PSYCHiatric Development (COPYCH) project nested within the Copenhagen Prospective Studies on Asthma in Childhood 2010 (COPSAC2010) cohort comprising a population-based sample of 700 healthy mother-child pairs enrolled at week 24 of pregnancy. Maternal 25-hydroxy-vitamin D (25(OH)D) was measured at inclusion and 623 mothers were randomized 1:1 to either high-dose (2800 IU/d) or standard dose (400 IU/d) vitamin D3 until 1 wk postpartum (315 received high-dose, 308 standard dose). At age 10, diagnoses and symptom load of autism and ADHD, respectively, were established using the Kiddie-Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version. RESULTS: The psychopathologic evaluation was completed by 591 children aged 10 y, and 16 children (2.7%) were diagnosed with autism and 65 (11.0%) with ADHD. Hereof, 496 children participated in the vitamin D3 trial (246 received high-dose, 250 standard dose). Of these, 12 children (2.4%) were diagnosed with autism and 58 (11.7%) with ADHD. Higher maternal preintervention 25(OH)D levels were associated with a decreased risk of autism [odd ratio (OR) per 10 nmol/L: 0.76 (0.59,0.97); P = 0.034], lower autistic symptom load [ß per 10 nmol/L: -0.03 (-0.05,0.00); P = 0.024), and decreased risk of ADHD diagnosis (OR per 10 nmol/L: 0.88 (0.78,0.99); P = 0.033]. High-dose vitamin D3 supplementation was not associated with risk of autism or ADHD. CONCLUSIONS: Higher maternal preintervention 25(OH)D was associated with a decreased risk of autism, lower autistic symptom load, and decreased risk of ADHD diagnosis, but high-dose vitamin D3 supplementation in pregnancy had no effect on risk of autism and ADHD. This trial was registered at clinicaltrials.gov as NCT00856947.

Suicidal Ideation and Non-Suicidal Self-Injury Following Early Childhood Psychotic Experiences in Preadolescent Children at Familial High Risk of Schizophrenia or Bipolar Disorder-The Danish High Risk and Resilience Study, VIA 11.

BACKGROUND AND HYPOTHESIS: Suicide is a leading cause of death in youth and is often preceded by suicidal ideation (SI) and non-suicidal self-injury (NSSI). Identifying early markers of risk for SI and NSSI could improve timely identification of at-risk individuals. STUDY DESIGN: Children (mean age 11.9, SD 0.2) at familial high risk of schizophrenia (N = 171), or bipolar disorder (N = 104), and controls (N = 174) were assessed for psychotic experiences (PE), SI, NSSI, and Axis I mental disorders in face-to-face interviews in early and middle childhood (age 7 and 11). STUDY RESULTS: Having 2 types of early childhood PE predicted middle childhood SI after accounting for previous SI, NSSI, and mental disorders (OR 2.8, 95% CI 1.1-6.9; P = .03). Two PE predicted NSSI (OR 3.0, 95% CI 1.2-7.7; P = .02) in excess of previous SI, NSSI, mental disorders, and familial risk. Persistent and incident PE predicted SI (OR 3.2, 95% CI, 1.1-8.8; P = .03; OR 3.8, 95% CI, 1.3-11.5; P = .02) in the fully adjusted model. Nineteen percent of children with persistent PE reported middle childhood SI vs 3.8% of those who never reported PE. In children with early childhood mental disorders, those who reported 2 PE had 4.4-fold increased odds of later SI (95% CI, 1.2-16.7; P = .03) after adjustments. PE were nondifferentially associated with outcomes across familial risk groups. CONCLUSIONS: Early childhood PE index elevated risk for subsequent SI and NSSI beyond what can be attributed to presence of mental disorders. Mental health screenings and clinical assessments should include early childhood PE.

Hair cortisol concentrations and daily life stress in 7-year-old children at familial high-risk of schizophrenia or bipolar disorder. The Danish High Risk and Resilience Study - VIA 7.

BACKGROUND: Dysregulation of the HPA-axis, perceived stress and interpersonal trauma are associated with an elevated risk for schizophrenia and bipolar disorder. Being at familial high-risk of these two mental disorders also constitutes an increased risk. In this study, we aimed to investigate hair cortisol concentrations and perceived stress among 7-year-old children at familial high-risk of schizophrenia (FHR-SZ), bipolar disorder (FHR-BP), and population-based controls (controls). METHODS: A total of 515 children (mean age 7.8, SD 0.2) from baseline assessment of the Danish High Risk and Resilience Study - VIA 7 participated in this study. Hair cortisol concentrations were analyzed among 322 children (FHR-SZ; N = 111, FHR-BP; N = 82, controls; N = 129). Perceived stress was assessed with the Daily Life Stressor Scale including 512 children (FHR-SZ; N = 195, FHR-BP; N = 118, controls; N = 199). Interpersonal trauma was measured with face-to-face interviews. RESULTS: Seven-year-old children at FHR-SZ or FHR-BP did not have a higher level of hair cortisol concentrations compared with controls (FHR-SZ: mean: 5.10, 95%CI 3.69-6.52; FHR-BP: mean: 5.01, 95%CI 3.27-6.72; controls: mean: 4.51, 95%CI 3.61-5.40; p = 0.77). Self-reported perceived stress was higher among children at FHR-SZ and FHR-BP compared with controls (FHR-SZ: mean: 12.09, 95%CI 10.99-13.19; FHR-BP: mean: 10.69, 95%CI 9.38-11.99; controls: mean: 8.90, 95%CI 8.13-9.68; p < 0.001). There was no significant association between hair cortisol concentrations and perceived stress (p = 0.84). Exploratory analyses revealed that interpersonal trauma exposure was neither associated with elevated hair cortisol nor perceived stress. CONCLUSIONS: Children at FHR-SZ and FHR-BP did not exhibit higher levels of hair cortisol concentrations at age 7, while both FHR-groups had higher level of self-reported perceived stress compared with controls. Early attention to stress in children at FHR is crucial and these vulnerabilities should be targeted in future interventions studies.

Effects of methylphenidate on mismatch negativity and P3a amplitude of initially psychostimulant-naïve, adult ADHD patients.

BACKGROUND: Deficient information processing in ADHD theoretically results in sensory overload and may underlie the symptoms of the disorder. Mismatch negativity (MMN) and P3a amplitude reflect an individual's detection and subsequent change in attention to stimulus change in their environment. Our primary aim was to explore MMN and P3a amplitude in adult ADHD patients and to examine the effects of methylphenidate (MPH) on these measures. METHODS: Forty initially psychostimulant-naïve, adult ADHD patients without comorbid ASD and 42 matched healthy controls (HC) were assessed with an MMN paradigm at baseline. Both groups were retested after 6 weeks, in which patients were treated with MPH. RESULTS: Neither significant group differences in MMN nor P3a amplitude were found at baseline. Although 6-week MPH treatment significantly reduced symptomatology and improved daily functioning of the patients, it did not significantly affect MMN amplitude; however, it did significantly reduce P3a amplitude compared to the HC. Furthermore, more severe ADHD symptoms were significantly associated with larger MMN amplitudes in the patients, both at baseline and follow-up. CONCLUSION: We found no evidence for early information processing deficits in patients with ADHD, as measured with MMN and P3a amplitude. Six-week treatment with MPH decreased P3a but not MMN amplitude, although more severe ADHD-symptoms were associated with larger MMN amplitudes in the patients. Given that P3a amplitude represents an important attentional process and that glutamate has been linked to both ADHD and MMN amplitude, future research should investigate augmenting MPH treatment of less responsive adults with ADHD with glutamatergic antagonists.

Developmental Pathways and Clinical Outcomes of Early Childhood Psychotic Experiences in Preadolescent Children at Familial High Risk of Schizophrenia or Bipolar Disorder: A Prospective, Longitudinal Cohort Study - The Danish High Risk and Resilience Study, VIA 11.

OBJECTIVE: Psychotic experiences are common in children and adolescents and are associated with concurrent and subsequent psychopathology. Most findings originate from general population studies, whereas little is known of the clinical outcomes of psychotic experiences in children and adolescents at familial high risk of psychosis. We examined the prevalence of psychotic experiences in middle childhood and whether early childhood psychotic experiences and developmental pathways of psychotic experiences predicted mental disorders in middle childhood in children at familial high risk of schizophrenia (FHR-SZ), bipolar disorder (FHR-BP), and a population-based control group. METHODS: In a longitudinal population-based cohort study children at FHR-SZ (N=170), FHR-BP (N=103), and the control group (N=174) were assessed for psychotic experiences and axis I disorders with face-to-face interviews in early and middle childhood (at 7 and 11 years of age). RESULTS: Psychotic experiences were more prevalent in children at FHR-SZ (31.8%, odds ratio 2.1, 95% CI 1.3-3.4) than in the control group (18.4%) in middle childhood. Early childhood psychotic experiences predicted mental disorders in middle childhood after adjusting for early childhood disorders and familial risk (odds ratio 2.0, 95% CI 1.2-3.1). Having three or more psychotic experiences increased odds the most (odds ratio 2.5, 95% CI 1.1-5.7). Persistent psychotic experiences were associated with increased odds of middle childhood disorders (odds ratio 4.1, 95% CI 2.1-8.4). Psychotic experiences were nondifferentially associated with mental disorders across the three familial risk groups. CONCLUSIONS: Early childhood psychotic experiences predict mental disorders in middle childhood. Psychotic experiences index vulnerability for psychopathology nondifferentially in children at familial high risk and the control group. Psychotic experiences should be included in mental health screenings including children at familial high risk.

Cohort profile: life with neurofibromatosis 1 - the Danish NF1 cohort.

PURPOSE: The Danish neurofibromatosis 1 (NF1) cohort was initiated to study health-related, socioeconomic and psychological consequences of living with the monogenetic disorder NF1 using a nationwide and population-based approach. PARTICIPANTS: The cohort includes all 2467 individuals in Denmark who were hospitalised with or due to NF1 from 1977 to 2013 or registered in the RAREDIS Database (1995-2013), a national clinical database for rare diseases, or both. A comparison cohort matched to individuals with NF1 on sex and date of birth was identified in the Civil Registration System (n=20 132). FINDINGS TO DATE: All cohort members were linked to the unique Danish registries to obtain information on hospital contacts, birth outcomes, education and partnership. A questionnaire was completed by 244 of the 629 adult cohort members with NF1 registered in the RAREDIS Database to evaluate the psychosocial and emotional burden. Further, neuropsychological tests were performed on 103 adult cohort members with NF1 and 38 adult population comparisons. To date, six studies have been published. Individuals with NF1 had an increased risk for (1) hospitalisation for disorders affecting all organ systems of the body throughout all decades of life, (2) psychiatric disorders, (3) attaining a short or medium long education and (4) not forming a life partner. Women with NF1 had an increased risk for spontaneous abortions and stillbirths. Finally, adults with NF1 had an impaired quality of life and a high need for professional support for physical, psychological and work-related problems, which was partly associated with disease severity and visibility. FUTURE PLANS: The cohort will regularly be updated with newly diagnosed patients in the RAREDIS Database as well as with outcome information in the Danish registries. New studies are in progress to assess other medical and socioeconomic dimensions of living with NF1.

Childhood trauma in children at familial high risk of schizophrenia or bipolar disorder: A longitudinal study. The Danish High Risk and Resilience Study - VIA 7 and VIA 11.

OBJECTIVES: Childhood trauma increases the risk of developing mental illness as does being born to parents with schizophrenia or bipolar disorder. We aimed to compare prevalence of lifetime childhood trauma among 11-year-old children at familial high risk of schizophrenia (FHR-SZ) or bipolar disorder (FHR-BP) compared with population-based controls (PBCs). DESIGN: The study is a longitudinal, prospective cohort study of children at FHR-SZ, FHR-BP, and PBCs. METHODS: A cohort of 512 children at FHR-SZ (N = 199), FHR-BP (N = 118), and PBCs (N = 195) were examined at baseline (mean age 7.8, SD 0.2) and 451 children at FHR-SZ (N = 172), FHR-BP (N = 104), and PBCs (N = 175) were examined at four-year follow-up (mean age 11.9, SD 0.2, retention rate 87.3%). Childhood trauma was measured with a semi-structured interview. RESULTS: Children at FHR-BP had an elevated risk of exposure to any lifetime trauma (age 0-11 years) compared with PBCs (OR 2.082, 95%CI 1.223-3.545, p = .007) measured with binary logistic regression. One-way ANOVA revealed that both FHR-groups had a higher lifetime prevalence of exposure to a greater number of types of trauma compared with PBCs (FHR-SZ: observed mean: 1.53, 95%CI 1.29-1.77; FHR-BP: observed mean: 1.56, 95%CI 1.26-1.85; PBCs: observed mean: 0.99, 95%CI 0.82-1.17; p < .001). Binary logistic regression showed that the lifetime risk of exposure to interpersonal trauma (age 0-11 years) was elevated for both FHR-groups (FHR-SZ: OR 3.773, 95%CI 2.122-6.710, p < .001; FHR-BP: OR 3.602, 95%CI 1.913-6.783, p < .001). CONCLUSIONS: Children at FHR-SZ and FHR-BP are at increased risk for being exposed to childhood trauma compared with PBCs. This study underscores the need for early detection, support, and prevention of childhood trauma in children at FHR-SZ and FHR-BP.

Effects of prenatal nutrient supplementation and early life exposures on neurodevelopment at age 10: a randomised controlled trial - the COPSYCH study protocol.

INTRODUCTION: Nutrient deficiency and immune and inflammatory disturbances in early life may compromise neurodevelopment and be implicated in the aetiology of psychiatric disorders. However, current evidence is limited by its predominantly observational nature. COpenhagen Prospective Study on Neuro-PSYCHiatric Development (COPSYCH) is a research alliance between Copenhagen Prospective Studies on Asthma in Childhood (COPSAC) and Center for Clinical Intervention and Neuropsychiatric Schizophrenia Research with the overall aim to investigate effects of prenatal and early life exposures on neurodevelopment at 10 years. COPSYCH will investigate the impact of prenatal n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) and high-dose vitamin D supplementation on neurodevelopment reflected by brain development, neurocognition and psychopathology. Moreover, the neurodevelopmental impact of early life exposures such as infections, low grade inflammation and the gut microbiome will be scrutinised. METHODS AND ANALYSIS: COPSYCH is based on the prospective and ongoing COPSAC2010 birth cohort of 700 mother-child pairs. Randomised controlled trials of supplementation with n-3 LCPUFA and/or high-dose vitamin D or placebo in the third trimester were embedded in a factorial 2×2 design (ClinicalTrials.gov: NCT01233297 and NCT00856947). This unique cohort provides deep phenotyping data from 14 previous clinical follow-up visits and exposure assessments since birth. The ongoing 10-year visit is a 2-day visit. Day 1 includes a comprehensive neurocognitive examination, and assessment of psychopathological dimensions, and assessment of categorical psychopathology. Day 2 includes acquisition of brain structural, diffusion and functional sequences using 3 Tesla MRI. Study outcomes are neurocognitive, psychopathological and MRI measures. ETHICS AND DISSEMINATION: This study has been approved by the Danish National Committee on Health Research Ethics and The Danish Data Protection Agency. The study is conducted in accordance with the guiding principles of the Declaration of Helsinki. Parents gave written informed consent before enrolment.

Mental disorders in preadolescent children at familial high-risk of schizophrenia or bipolar disorder - a four-year follow-up study: The Danish High Risk and Resilience Study, VIA 11.

BACKGROUND: Children at familial high-risk of schizophrenia and bipolar disorder have an elevated prevalence of mental disorders but studies of children within a narrow age range are lacking and there are few conjoint studies of these two groups. Knowledge on their mental health is important for prevention and early intervention. METHODS: The authors examined mental disorders and global functioning in children at familial high-risk of schizophrenia (FHR-SZ) and bipolar disorder (FHR-BP) compared with population-based controls. In a longitudinal cohort study, 450 children (FHR-SZ, n = 171; FHR-BP, n = 104; controls, n = 175), were assessed for Axis I disorders at baseline and four-year follow-up (mean age 11.9, SD 0.2) with the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children and for global functioning with Children's Global Assessment Scale. RESULTS: Cumulative incidence of Any Axis I disorder was elevated by age 11 in children at FHR-SZ (54.4%, OR 3.0, 95% CI 1.9-4.7, p < .001) and children at FHR-BP (52.9%, OR 2.8, 95% CI 1.7-4.7, p < .001) compared with controls (28.6%). Children at FHR-SZ and FHR-BP had higher rates of affective disorders (OR 4.4, 95% CI 1.4-13.5, p = .009; OR 5.1, 95% CI 1.6-16.4, p = .007), anxiety disorders (OR 2.1, 95% CI 1.1-4.0, p = .02; OR 3.0, 95% CI 1.5-6.1, p = .002), and stress and adjustment disorders (OR 3.3, 95% CI 1.4-7.5, p = .006; OR 5.3, 95% CI 2.2-12.4, p < .001). Disruptive behavior disorders (OR 2.8, 95% CI 1.0-7.3, p = .04) and ADHD (OR 2.9, 95% CI 1.6-5.3, p < .001) were elevated in children at FHR-SZ. Both FHR groups had lower global functioning than controls. Cumulative incidence of disorders increased equally across the three groups from early childhood to preadolescence and level of functioning did not change differentially. CONCLUSIONS: Children at FHR-SZ and FHR-BP have an elevated prevalence of mental disorders and poorer functioning than controls. Vulnerability in children at FHR manifests early and remains stable throughout childhood. Early attention toward their mental health and identification of those in need of intervention is warranted.

Development of visual attention from age 7 to age 12 in children with familial high risk for schizophrenia or bipolar disorder.

BACKGROUND: Children with familial high risk of schizophrenia (FHR-SZ) or bipolar disorder (FHR-BP) are at increased risk of developing similar disorders and show cognitive deficits during childhood. The aim of this paper is to investigate visual attention and its developmental trajectories in children with FHR-SZ and with FHR-BP to increase our knowledge about potential cognitive endophenotypes of these two disorders. METHODS: We compared the performance of 89 children with FHR-SZ (N = 32), FHR-BP (N = 22), and population-based controls (PBC, N = 35) at age 7 to that at age 12 as well as including 133 12-year-old children with FHR-SZ (N = 50), FHR-BP (N = 43) and PBC (N = 40) to investigate visual attention, as part of the Danish High Risk and Resilience Study. We used the TVA-based whole report paradigm, based on the Bundesen's Theory of Visual Attention (TVA) to investigate visual attention. RESULTS: Children with FHR-SZ that showed deficits in visual processing speed at age 7 improved to a level that was not significantly different from controls at age 12. All children improved over time. We found no attentional deficits in FHR children at age 12. CONCLUSIONS: On visual attention, children with FHR-SZ did not show developmental deficits or lags and, together with children with FHR-BP, they develop similarly to control children between age 7 to age 12. This emphasizes the potential of beneficial neuroplastic changes in cognitive deficits found at younger ages in children with FHR-SZ. It also highlights the importance of identifying and characterizing cognitive developmental trajectories of high-risk children and provides hope that visual attention may develop appropriately in these groups.

Measuring movements in adolescents with psychosis using the Microsoft Kinect sensor: a pilot study exploring a new tool for assessing aspects of antipsychotic-induced parkinsonism.

BACKGROUND: The assessment of motor disturbances in antipsychotic-treated adolescent patients is often limited to the use of observer-based rating scales with interobserver variability. The objectives of this pilot study were to measure movement patterns associated with antipsychotic-induced parkinsonism in young patients with psychosis and initiating/treated with antipsychotics, using a computer application connected with the Microsoft Kinect sensor (Motorgame). METHOD: All participants were assessed by neurological examination, clinical side effect rating scales (Udvalg for Kliniske Undersøgelser Side Effect Rating Scale, Barnes Akathisia Rating Scale, Simpson Angus Scale (SAS), and Abnormal Involuntary Movement Scale), and the Motorgame. Furthermore, speed of information processing and motor speed with subtests from the Brief Assessment of Cognition in Schizophrenia test battery was assessed. RESULTS: We included 21 adolescents with first-episode psychosis (62% treated with antipsychotics; males 38%; mean age 16 ± 1.4 years) and 69 healthy controls (males 36%; mean age 16 ± 1.5 years). Prolonged time of motor performance (TOMP) in the Motorgame was associated with higher SAS scores for arm dropping (p = .009). A consistent practice effect was detected (p < .001). We found no significant associations between TOMP and age, height, body weight, sex, antipsychotic dosage, or information processing speed. CONCLUSIONS: We found an uncorrected significant association between prolonged TOMP and shoulder bradykinesia. The Motorgame was found useful in assessing parkinsonian symptoms in early-onset psychosis and accepted by participants. Future studies of larger cohorts, including patients with high scores in clinical motor side effect scales, are required to establish solid validity of the novel test.

Odor identification in 7-year-old children at familial high risk of schizophrenia or bipolar disorder - the Danish high risk and resilience study VIA 7.

BACKGROUND: Odor identification deficits occur in individuals with schizophrenia and their unaffected first-degree relatives, while deficits are less pronounced in individuals with bipolar disorder. We hypothesized that children at familial high-risk for schizophrenia (FHR-SZ) show odor identification deficits compared to population-based controls and that children at familial high-risk for bipolar disorder (FHR-BP) perform intermediate. METHODS: Odor identification was assessed at age 7 in 184 children with FHR-SZ, 106 children with FHR-BP, and 186 population-based controls with the Brief Smell Identification Test. Dimensional and predefined categorical outcomes were used in the analyses. Potential relationships with psychopathological, cognitive, and home environmental variables were conducted using hierarchical and logistic multiple regression analyses. RESULTS: ANOVA revealed no between-group differences in odor identification. Using the recommended cut-off (below 5), we found a significantly greater proportion of boys at FHR-SZ than population-based boys with an abnormal odor identification (p = .013). However, a supplementary analysis using a Danish-based cut-off (below 4) did not support this. All children showed significant, positive associations of odor identification with female gender, social responsiveness, and verbal working memory. Lower social responsiveness predicted abnormal odor identification in boys at FHR-SZ, only using the recommended cut-off. CONCLUSIONS: Odor identification efficacy and risk status appear independent in this early developmental phase. Using the recommended threshold, abnormal odor identification is more frequent in young boys at FHR-SZ than in population-based boys and is linked to lower social responsiveness. The validity of these results is questioned by non-significant differences in the rates when using an exploratory Danish-based threshold.

Hippocampal Volume, Cognitive Functions, Depression, Anxiety, and Quality of Life in Patients With Cushing Syndrome.

CONTEXT: Cushing syndrome (CS) is associated with hippocampal atrophy and psychopathology. OBJECTIVE: The primary objective of this systematic review was to assess hippocampal volume (HV) in patients with CS. The secondary objectives were to assess patients' cognitive functioning, depressive and anxiety symptoms, and quality of life. DATA SOURCES: PubMed, Embase, Cochrane, LILACs, and Scopus databases were searched for relevant studies until 1 May 2019. STUDY SELECTION: Case-control studies comparing patients with CS with healthy control subjects, or studies assessing patients with CS before and after surgery were included. The initial search resulted in 18 studies fulfilling the inclusion criteria. DATA EXTRACTION: Data extraction regarding all outcomes was performed independently by two reviewers. Quality assessment was assessed with the Newcastle-Ottawa Scale for case-control studies. DATA SYNTHESIS: Meta-analysis was performed using a random effect model. The right-side HV in patients with CS was reduced by a standard mean difference of 0.68 (95% CI, -1.12 to -0.24; P = 0.002; I2 = 0%) compared with healthy control subjects, but with no increase in HV after surgery. Patients had more depressive symptoms, impaired cognitive functions, and reduced health-related QoL (HRQoL), which all responded favorably to surgery. The data did not support the presence of anxiety in patients with CS. CONCLUSION: An overall reduction of HV in patients with CS was not suggested by the study findings. However, most cognitive domains were significantly affected and responded favorably to surgery. Depressive symptoms and reduced HRQoL were present in patients with CS and improved after surgery.

Auditory processing in autism spectrum disorder: Mismatch negativity deficits.

Children with autism spectrum disorders (ASD) often show changes in (automatic) auditory processing. Electrophysiology provides a method to study auditory processing, by investigating event-related potentials such as mismatch negativity (MMN) and P3a-amplitude. However, findings on MMN in autism are highly inconsistent, partly due to small sample sizes in the studies and differences in MMN paradigms. Therefore, in the current study, MMN and P3a amplitude were assessed in a relatively large sample of children with ASD, using a more extensive MMN paradigm and compared with that of typically developing children (TDC). Thirty-five children (aged 8-12 years) with ASD and 38 age and gender matched TDC were assessed with a MMN paradigm with three types of deviants, i.e., frequency, duration and a combination of these two. MMN elicited by duration and frequency-duration deviants was significantly reduced in the ASD group. P3a-amplitude elicited by duration deviants was significantly increased in the ASD group. Reduced MMN in children with ASD suggests that children with ASD may be less responsive to environmentally deviant stimuli at an early (sensory) level. P3a-amplitude was increased in ASD, implying a hyper-responsivity at the attentional level. In addition, as similar MMN deficits are found in schizophrenia, these MMN results may explain some of the frequently reported increased risk of children with ASD to develop schizophrenia later in life. Autism Res 2017, 10: 1857-1865. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Automatic detection of deviant sounds in the environment, such as upcoming traffic, is often affected in children with autism spectrum disorders (ASD). Mismatch negativity (MMN) is a way to quantify automatic deviancy detection, using electroencephalography. In this study, auditory MMN was assessed in 35 children with ASD and 38 matched control children, revealing significantly reduced MMN in the ASD group. This may indicate that children with ASD are less able to automatically detect environmentally deviant stimuli.