Combining developmental and sleep health measures for autism spectrum disorder screening: an ECHO study.

BACKGROUND: Sleep problems are reported for up to 80% of autistic individuals. We examined whether parsimonious sets of items derived from the Modified Checklist for Autism in Toddlers, Revised (M-CHAT-R) and the Brief Infant Sleep Questionnaire (BISQ) are superior to the standard M-CHAT-R in predicting subsequent autism spectrum disorder (ASD) diagnoses. METHODS: Participants from 11 Environmental influences on Child Health Outcomes (ECHO) cohorts were included. We performed logistic LASSO regression models with 10-fold cross-validation to identify whether a combination of items derived from the M-CHAT-R and BISQ are superior to the standard M-CHAT-R in predicting ASD diagnoses. RESULTS: The final sample comprised 1552 children. The standard M-CHAT-R had a sensitivity of 44% (95% CI: 34, 55), specificity of 92% (95% CI: 91, 94), and AUROC of 0.726 (95% CI: 0.663, 0.790). A higher proportion of children with ASD had difficulty falling asleep or resisted bedtime during infancy/toddlerhood. However, LASSO models revealed parental reports of sleep problems did not improve the accuracy of the M-CHAT-R in predicting ASD diagnosis. CONCLUSION: While children with ASD had higher rates of sleep problems during infancy/toddlerhood, there was no improvement in ASD developmental screening through the incorporation of parent-report sleep metrics. IMPACT: Parental-reported sleep problems are common in autism spectrum disorder (ASD). We investigated whether the inclusion of parental-reports of infant/toddler sleep patterns enhanced the effectiveness of developmental screening for autism. We reported higher rates of difficulty falling asleep and resisting bedtime during infancy and toddlerhood among children later diagnosed with ASD; however, we did not find an improvement in ASD developmental screening through the incorporation of parent-report sleep metrics. In our sample, the standard M-CHAT-R had a sensitivity of 39% among children of mothers with government insurance compared with a sensitivity of 53% among children of mothers with employer-based insurance.

Scoping Review: Digital Mental Health Interventions for Children and Adolescents Affected by War.

OBJECTIVE: More than 200 million children and adolescents live in countries affected by violent conflict, are likely to have complex mental health needs, and struggle to access traditional mental health services. Digital mental health interventions have the potential to overcome some of the barriers in accessing mental health support. We performed a scoping review to map existing digital mental health interventions relevant for children and adolescents affected by war, to examine the strength of the evidence base, and to inform the development of future interventions. METHOD: Based on a pre-registered strategy, we systematically searched MEDLINE, Embase, Global Health, APA PsychInfo, and Google Scholar from the creation of each database to September 30, 2022, identifying k = 6,843 studies. Our systematic search was complemented by extensive consultation with experts from the GROW Network. RESULTS: The systematic search identified 6 relevant studies: 1 study evaluating digital mental health interventions for children and adolescents affected by war, and 5 studies for those affected by disasters. Experts identified 35 interventions of possible relevance. The interventions spanned from universal prevention to specialist-guided treatment. Most interventions directly targeted young people and parents or carers/caregivers and were self-guided. A quarter of the interventions were tested through randomized controlled trials. Because most interventions were not culturally or linguistically adapted to relevant contexts, their implementation potential was unclear. CONCLUSION: There is very limited evidence for the use of digital mental health interventions for children and adolescents affected by war at present. The review provides a framework to inform the development of new interventions. DIVERSITY & INCLUSION STATEMENT: We actively worked to promote sex and gender balance in our author group. STUDY PREREGISTRATION INFORMATION: Digital mental health interventions for children and young people affected by war: a scoping review; https://osf.io/; hrny9.

A review of information sources and analysis methods for data driven decision aids in child and adolescent mental health services.

OBJECTIVE: Clinical data analysis relies on effective methods and appropriate data. Recognizing distinctive clinical services and service functions may lead to improved decision-making. Our first objective is to categorize analytical methods, data sources, and algorithms used in current research on information analysis and decision support in child and adolescent mental health services (CAMHS). Our secondary objective is to identify the potential for data analysis in different clinical services and functions in which data-driven decision aids can be useful. MATERIALS AND METHODS: We searched related studies in Science Direct and PubMed from 2018 to 2023(Jun), and also in ACM (Association for Computing Machinery) Digital Library, DBLP (Database systems and Logic Programming), and Google Scholar from 2018 to 2021. We have reviewed 39 studies and extracted types of analytical methods, information content, and information sources for decision-making. RESULTS: In order to compare studies, we developed a framework for characterizing health services, functions, and data features. Most data sets in reviewed studies were small, with a median of 1,176 patients and 46,503 record entries. Structured data was used for all studies except two that used textual clinical notes. Most studies used supervised classification and regression. Service and situation-specific data analysis dominated among the studies, only two studies used temporal, or process features from the patient data. This paper presents and summarizes the utility, but not quality, of the studies according to the care situations and care providers to identify service functions where data-driven decision aids may be relevant. CONCLUSIONS: Frameworks identifying services, functions, and care processes are necessary for characterizing and comparing electronic health record (EHR) data analysis studies. The majority of studies use features related to diagnosis and assessment and correspondingly have utility for intervention planning and follow-up. Profiling the disease severity of referred patients is also an important application area.

Adaptation of the Strength and Difficulties Questionnaire for Use in the Republic of Georgia.

Background: Children in low-resource countries like Georgia often have limited access to assessment measures for mental health care services. This study adapts and validates the mental health screening tool the Strength and Difficulties Questionnaire for use in Georgian children. Methods: A total of 16 654 children were assessed by a parent and/or teacher using Georgian-adapted Strength and Difficulties Questionnaire. Receiver operating characteristic analyses were performed to assess the discriminative validity of the Strength and Difficulties Questionnaires and to establish an optimal cutoff score. Results: Data from 15 738 parents- and 13 560 teachers-administered Strength and Difficulties Questionnaire were analyzed. The internal consistency analysis showed Cronbach's alpha to be 0.625 and 0.621 for parent- and teacher-administered Strength and Difficulties Questionnaire, respectively. The area under the curve (95% CI) shows that the Strength and Difficulties Questionnaire can differentiate risk group children from typically developing peers: parent-administered questionnaires-0.629 (0.556-0.702) and teacher-administered questionnaires-0.680 (0.611-0.789). Parent-administered Strength and Difficulties Questionnaire has a cutoff value of 16 or more with 92.5% of sensitivity and teacher-administered Strength and Difficulties Questionnaire-14 or more with a sensitivity of 85.6%. Conclusion: The study finds that the Strength and Difficulties Questionnaire is a valid screening instrument and does not depend on the informant-parent or teacher. It suggests that with appropriate cultural adaptation, the SDQ can be used in the Republic of Georgia to identify children at risk for mental disorders and help guide resource allocation.

Neurodevelopmental profiles of 4-year-olds in the Navajo Birth Cohort Study.

Objective: Native American children disproportionally face many risk factors for poor developmental outcomes; these factors include poverty, environmental toxicant exposure, and limited medical, and intervention services. To understand these risks, comprehensive documentation of developmental and behavioral phenotypes are needed. In the current descriptive study, we assessed the neurodevelopment of young Diné (Navajo) children using standardized assessment instruments in combination with expert clinician judgment. Methods: As part of an ongoing, population-based, prospective birth cohort study, we conducted comprehensive neurodevelopmental assessments of 138, 3-5-year-old, Diné children residing on or near the Navajo Nation. We report results from standardized parent reports, psychiatric examinations, and direct assessments of children's language, cognitive, adaptive, and social-emotional development, as well as best estimate clinical diagnoses. Results: Forty-nine percent of our sample met DSM-5 criteria for a neurodevelopmental disorder (NDD) diagnosis. Language and speech sound disorders were most common, although autism spectrum disorder (ASD) was also elevated compared to the general population. Though language performance was depressed amongst all groups of children with, and without, NDDs, those meeting criteria for certain NDDs performed significantly lower on all language measures, when compared to those without. Social-emotional, behavioral, and nonverbal cognitive ability were in the average range overall. Conclusions: Diné children in our study were found to have a high percentage of clinically significant developmental delays. Overall, children presented with a pervasive pattern of depressed language performance across measures, irrespective of diagnosis (or no diagnosis), while other domains of functioning were similar to normative samples. Findings support the need to identify appropriate intervention and educational efforts for affected youth, while also exploring the causes of the specific developmental delays. However, longitudinal studies are necessary to establish best practices for identifying delays and delineating resilience factors to optimize development of Diné children.

A longitudinal resource for studying connectome development and its psychiatric associations during childhood.

Most psychiatric disorders are chronic, associated with high levels of disability and distress, and present during pediatric development. Scientific innovation increasingly allows researchers to probe brain-behavior relationships in the developing human. As a result, ambitions to (1) establish normative pediatric brain development trajectories akin to growth curves, (2) characterize reliable metrics for distinguishing illness, and (3) develop clinically useful tools to assist in the diagnosis and management of mental health and learning disorders have gained significant momentum. To this end, the NKI-Rockland Sample initiative was created to probe lifespan development as a large-scale multimodal dataset. The NKI-Rockland Sample Longitudinal Discovery of Brain Development Trajectories substudy (N = 369) is a 24- to 30-month multi-cohort longitudinal pediatric investigation (ages 6.0-17.0 at enrollment) carried out in a community-ascertained sample. Data include psychiatric diagnostic, medical, behavioral, and cognitive phenotyping, as well as multimodal brain imaging (resting fMRI, diffusion MRI, morphometric MRI, arterial spin labeling), genetics, and actigraphy. Herein, we present the rationale, design, and implementation of the Longitudinal Discovery of Brain Development Trajectories protocol.

Familial coaggregation of major psychiatric disorders in first-degree relatives of individuals with autism spectrum disorder: a nationwide population-based study.

BACKGROUND: Family coaggregation of attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), bipolar disorder (BD), major depressive disorder (MDD) and schizophrenia have been presented in previous studies. The shared genetic and environmental factors among psychiatric disorders remain elusive. METHODS: This nationwide population-based study examined familial coaggregation of major psychiatric disorders in first-degree relatives (FDRs) of individuals with ASD. Taiwan's National Health Insurance Research Database was used to identify 26 667 individuals with ASD and 67 998 FDRs of individuals with ASD. The cohort was matched in 1:4 ratio to 271 992 controls. The relative risks (RRs) and 95% confidence intervals (CI) of ADHD, ASD, BD, MDD and schizophrenia were assessed among FDRs of individuals with ASD and ASD with intellectual disability (ASD-ID). RESULTS: FDRs of individuals with ASD have higher RRs of major psychiatric disorders compared with controls: ASD 17.46 (CI 15.50-19.67), ADHD 3.94 (CI 3.72-4.17), schizophrenia 3.05 (CI 2.74-3.40), BD 2.22 (CI 1.98-2.48) and MDD 1.88 (CI 1.76-2.00). Higher RRs of schizophrenia (4.47, CI 3.95-5.06) and ASD (18.54, CI 16.18-21.23) were observed in FDRs of individuals with both ASD-ID, compared with ASD only. CONCLUSIONS: The risk for major psychiatric disorders was consistently elevated across all types of FDRs of individuals with ASD. FDRs of individuals with ASD-ID are at further higher risk for ASD and schizophrenia. Our results provide leads for future investigation of shared etiologic pathways of ASD, ID and major psychiatric disorders and highlight the importance of mental health care delivered to at-risk families for early diagnoses and interventions.

Parent-Reported Suicidal Ideation in Three Population-Based Samples of School-Aged Korean Children With Autism Spectrum Disorder and Autism Spectrum Screening Questionnaire Screen Positivity.

OBJECTIVES: Higher prevalence of suicidality has been reported in individuals with ASD. This study aimed to (1) Estimate the prevalence of suicidal ideation (SI) in epidemiologically-ascertained, population-based, samples of children with ASD or Autism Spectrum Screening Questionnaire (ASSQ) Screen Positivity (ASP); (2) Determine whether ASD/ASP is an independent risk factor for SI, controlling for known SI risk factors; and, (3) Develop an explanatory model for SI in children with ASD/ASP. METHODS: Participants came from three epidemiologically-ascertained samples of school-aged Korean children (n = 14,423; 3,702; 4,837). ASSQ ≥ 14 was the cutoff for ASP. A subsample (n = 86) was confirmed to have ASD. SI was based on parents' endorsement of items on the Behavioral Assessment System for Children-2-Parent Report Scale-Children. Logistic regressions were used to assess associations between SI and ASD/ASP, controlling for demographics, peer victimization, behavior problems, and depression. To develop an explanatory model for SI within ASD/ASP, the associations between SI and child characteristics (comorbid conditions, ASD symptoms, IQ, adaptive function) were tested. RESULTS: SI was higher in children with ASD (14%) and ASP (16.6-27.4%) than ASSQ Screen Negative (ASN) peers (3.4-6.9%). ASD/ASP was strongly predictive of SI (ORs: 2.87-5.67), after controlling for known SI risk factors compared to ASN. Within the ASD and ASP groups, anxiety was the strongest predictor of SI. CONCLUSIONS: SI prevalence was higher in non-clinical samples of children with ASD and ASP, relative to ASN peers. These results underscore the need for routine screening for SI in children with ASD and social difficulties, particularly those with high anxiety. HighlightsPopulation-based, epidemiologically-ascertained, school-aged childrenASD and ASP are independent risk factors for SI in school-aged childrenAnxiety is an independent risk factor for SI in children with ASD or ASP.

Prenatal exposure to paternal smoking and likelihood for autism spectrum disorder.

LAY ABSTRACT: What is Already Known about This Subject: Genetics, (including de novo mutations), environmental factors (including toxic exposures), and their interactions impact autism spectrum disorder etiology. Paternal smoking is a candidate risk for autism spectrum disorder due to biological plausibility, high prevalence, and potential intervention.What This Study Adds: This original study and its replication confirms that paternal factors can substantially contribute to autism spectrum disorder risk for their offspring. It specifically indicates that paternal smoking both before and during pregnancy contributes significantly to autism spectrum disorder risk.Implications for practice, research, or policy: Smoking prevention, especially in pregnancy planning, may decrease autism spectrum disorder risk in offspring.

Differences in the Severity and Variability of Restricted and Repetitive Behaviors in ASD Children With and Without Service Experiences.

BACKGROUND: Despite the importance of restricted and repetitive behaviors (RRBs) in diagnosing autism spectrum disorder (ASD), specific RRBs that distinguish children with ASD who are receiving services from those who have ASD but are unidentified and untreated until school age remain unclear. This study examined the differences in the severity and variability of RRBs among three groups (ASD with service experiences [ASDws], ASD without service experiences [ASDwos], and No ASD) and investigated specific RRBs predicting group membership. METHOD: A total of 296 children who screened positive for ASD completed confirmative diagnostic assessments. The severity and variability scores of RRBs were obtained using 16 items of the Autism Diagnostic Interview-Revised. RESULTS: Both ASD groups had higher proportions of children with severe RRBs for the majority of RRBs and exhibited a greater number of RRBs than the No ASD group. However, discrepancies between the ASDwos and the No ASD groups were not as apparent as those between the ASDws and the No ASD groups. RRBs characterized by a repetitive motor/physical component and unusual sensory responses differentiated the ASDws group from the ASDwos group. Conversely, RRBs characterized by rigid adherence to routine, and ritualistic behavior increased the odds of membership in the ASDwos group over the No ASD group. CONCLUSIONS: Our results may improve the ability of clinicians and parents to detect ASD in the community by observing specific RRBs, especially in cognitively intact school-aged children who show significant compulsive/ritualistic behaviors and rigidity to routines/sameness RRBs, even in the absence of multiple RRBs or severe repetitive sensorimotor behaviors.

Prevalence of and Factors Associated with School Bullying in Students with Autism Spectrum Disorder: A Cross-Cultural Meta-Analysis.

Through this meta-analysis, we sought to examine the prevalence of, risks for, and factors associated with bullying involvement (victimization, perpetration, perpetration-victimization) among students with autism spectrum disorder (ASD). Additionally, we attempted to examine sources of variance in the prevalence and effect sizes of bullying in students with ASD across studies. Systematic database and literature review identified 34 relevant studies (31 for Western countries, three for Eastern countries). Pooled prevalence estimates for victimization, perpetration, and perpetration-victimization in general were 67%, 29%, and 14%, respectively. The risk of victimization in students with ASD was significantly higher than that in typically developing students and students with other disabilities. Further, deficits in social interaction and communication, externalizing symptoms, internalizing symptoms, and integrated inclusive school settings were related to higher victimization, and externalizing symptoms were related to higher perpetration. Finally, moderation analyses revealed significant variations in the pooled prevalences thereof depending on culture, age, school settings, and methodological quality and in the pooled effect sizes according to publication year and methodological quality. Our results highlight needs for bullying intervention for students with ASD, especially those who are younger, are in an inclusive school setting, and have higher social difficulties and externalizing/internalizing symptoms; for intensive research of bullying experiences among students with ASD in Eastern countries; and for efforts to improve the methodological quality of such research.

Testing an individualized digital decision assist system for the diagnosis and management of mental and behavior disorders in children and adolescents.

BACKGROUND: Nearly half of all mental health disorders develop prior to the age of 15. Early assessments, diagnosis, and treatment are critical to shortening single episodes of care, reducing possible comorbidity and long-term disability. In Norway, approximately 20% of all children and adolescents are experiencing mental health problems. To address this, health officials in Norway have called for the integration of innovative approaches. A clinical decision support system (CDSS) is an innovative, computer-based program that provides health professionals with clinical decision support as they care for patients. CDSS use standardized clinical guidelines and big data to provide guidance and recommendations to clinicians in real-time. IDDEAS (Individualised Digital DEcision Assist System) is a CDSS for diagnosis and treatment of child and adolescent mental health disorders. The aim of IDDEAS is to enhance quality, competency, and efficiency in child and adolescent mental health services (CAMHS). METHODS/DESIGN: IDDEAS is a mixed-methods innovation and research project, which consists of four stages: 1) Assessment of Needs and Preparation of IDDEAS; 2) The Development of IDDEAS CDSS Model; 3) The Evaluation of the IDDEAS CDSS; and, 4) Implementation & Dissemination. Both qualitative and quantitative methods will be used for the evaluation of IDDEAS CDSS model. Child and adolescent psychologists and psychiatrists (n = 30) will evaluate the IDDEAS` usability, acceptability and relevance for diagnosis and treatment of attention-deficit/hyperactivity disorder. DISCUSSION: The IDDEAS CDSS model is the first guidelines and data-driven CDSS to improve efficiency of diagnosis and treatment of child and adolescent mental health disorders in Norway. Ultimately, IDDEAS will help to improve patient health outcomes and prevent long-term adverse outcomes by providing each patient with evidence-based, customized clinical care. TRIAL REGISTRATION: ISRCTN, ISRCTN12094788. Ongoing study, registered prospectively 8 April 2020 https://doi.org/10.1186/ISRCTN12094788.

Identifying the Medical Lethality of Suicide Attempts Using Network Analysis and Deep Learning: Nationwide Study.

BACKGROUND: Suicide is one of the leading causes of death among young and middle-aged people. However, little is understood about the behaviors leading up to actual suicide attempts and whether these behaviors are specific to the nature of suicide attempts. OBJECTIVE: The goal of this study was to examine the clusters of behaviors antecedent to suicide attempts to determine if they could be used to assess the potential lethality of the attempt. To accomplish this goal, we developed a deep learning model using the relationships among behaviors antecedent to suicide attempts and the attempts themselves. METHODS: This study used data from the Korea National Suicide Survey. We identified 1112 individuals who attempted suicide and completed a psychiatric evaluation in the emergency room. The 15-item Beck Suicide Intent Scale (SIS) was used for assessing antecedent behaviors, and the medical outcomes of the suicide attempts were measured by assessing lethality with the Columbia Suicide Severity Rating Scale (C-SSRS; lethal suicide attempt >3 and nonlethal attempt ≤3). RESULTS: Using scores from the SIS, individuals who had lethal and nonlethal attempts comprised two different network nodes with the edges representing the relationships among nodes. Among the antecedent behaviors, the conception of a method's lethality predicted suicidal behaviors with severe medical outcomes. The vectorized relationship values among the elements of antecedent behaviors in our deep learning model (E-GONet) increased performances, such as F1 and area under the precision-recall gain curve (AUPRG), for identifying lethal attempts (up to 3% for F1 and 32% for AUPRG), as compared with other models (mean F1: 0.81 for E-GONet, 0.78 for linear regression, and 0.80 for random forest; mean AUPRG: 0.73 for E-GONet, 0.41 for linear regression, and 0.69 for random forest). CONCLUSIONS: The relationships among behaviors antecedent to suicide attempts can be used to understand the suicidal intent of individuals and help identify the lethality of potential suicide attempts. Such a model may be useful in prioritizing cases for preventive intervention.

Pharmacotherapy of restricted/repetitive behavior in autism spectrum disorder:a systematic review and meta-analysis.

BACKGROUND: This paper is a systematic review and meta-analysis of the efficacy of available medications for the treatment of restricted/repetitive behavior (RRBs) in Autism Spectrum Disorder (ASD). METHOD: We searched MEDLINE, Embase, PsycINFO, The Cochrane Library (Cochrane Database of Systematic Reviews (CDRS), the Cochrane Central Register of Controlled Trials (CENTRAL), database of Abstracts of Reviews of Effects (DARE)), Scopus, Epistimonikos, Clinicaltrials.gov, and included all randomized controlled trials published after 1993 that were directed at RRBs in patients with ASD of all ages. We extracted the relevant data from the published studies with a predefined data extraction form and assessed the risk of bias. The primary outcomes were change in restricted/repetitive behavior. We performed a meta-analysis using the random effect model and included studies with given mean and standard deviation. This study is registered with PROSPERO number CRD42018092660). RESULTS: We identified 14 randomized controlled trials that met initial inclusion criteria. After closer inspection, nine trials - involving 552 patients in total - were included in the final analysis. The meta-analysis found no significant difference between medications (including fluvoxamine, risperidone, fluoxetine, citalopram, oxytocin, N-Acetylcysteine, buspirone) and placebo in the treatment of RRBs in ASD (P = 0.20). Similarly, the sub-group meta-analysis also showed no significant difference between Selective Serotonin Reuptake Inhibitor (SSRIs) and placebo in the treatment of RRBs in ASD (P = 0.68). There was no evidence of publication bias. CONCLUSION: This meta-analysis finds little support for the routine use of medications to treat restricted/repetitive behaviors in Autism Spectrum Disorder. Further research of large, balanced trials with precise assessment tools and long-term follow-up are needed. TRIAL REGISTRATION: The study protocol is registered in PROSPERO (Reference number: CRD42018092660).

Sex difference in risk period for completed suicide following prior attempts: Korea National Suicide Survey (KNSS).

OBJECTIVES: We provide an opportunity for implementing preventive interventions to decrease suicide mortality among prior suicide attempters. We aim to identify sex-specific high risk periods and factors for later suicide death among suicide attempters. METHODS: 8537 suicide attempters of Korea National Suicide Survey were collected from January 1, 2007 to December 31, 2011 and data on suicide death was obtained as of December 31, 2012. The risk period and risk factors for later suicide death was computed by Kaplan-Meier survival estimates and by plotting the hazard function using the Epanechnikov Kernal smoothing method and cox proportional hazard regression modeling. RESULTS: The hazard for later suicide death was significant up to 10 months for females and 20 months for males. Age 50-69 years (HR, 3.29; [CI: 1.80-6.02] and not being intoxicated with alcohol (HR, 1.94 [1.27-2.97])) in male attempters were significant risk factors for later suicide death. CONCLUSION: Risk for later suicide death was significantly increased during the first full year following index attempts for all with an addition 8 months of risk for males, especially those of advanced age who were sober at the time of attempt.

Autism Spectrum Disorder and School Bullying: Who is the Victim? Who is the Perpetrator?

While a growing number of studies indicate associations between experiences of bullying and autism spectrum disorder (ASD), it is not clear what roles comorbid behavioral problems may play. We investigated the experiences of children with ASD as victims and/or perpetrators of bullying. Children with ASD epidemiologically ascertained participated in a cross-sectional study. Although children with ASD showed significantly increased risk for bullying involvement compared to community children, after controlling for comorbid psychopathology and other demographic factors, increased risks for being perpetrators or victim-perpetrators disappeared while risk for being bullied/teased continued to be significantly elevated. This finding will help guide medical, educational and community personnel to effectively identify children with ASD at risk for school bullying and develop interventions.

Discrepancy in perception of bullying experiences and later internalizing and externalizing behavior: A prospective study.

Discrepancy in perception of bullying experiences may lead to later internalizing or externalizing behavior in adolescents. A 1,663 South Korean 7th and 8th graders (mean age: 13.1 and 14.1 years old), were seen for a follow-up study to examine the relationships between the discrepancy in perception of their bullying experiences (defined as discrepancy between self- and peer-reports of bullying experiences) and internalizing or externalizing behavior at follow-up. Bullying was assessed by self- and peer-report. The discrepancy in perception of bullying experiences was defined by the concordance or discordance between self- and peer-reports. Internalizing and externalizing behavior was evaluated using the Youth Self Report and Child Behavior Checklist, at baseline and follow-up. Two by two ANCOVA was performed with a factorial design, categorizing discrepancy in perception of bullying experiences based on the agreement between self-report and peer-report. Internalizing/externalizing behavior-at-follow-up was used as an outcome, adjusting for other known risk factors for internalizing/externalizing behavior, including baseline internalizing/externalizing behavior, and bullying experiences. Adolescents with perceptions of bullying experiences discrepant from peer-reports showed increased internalizing/externalizing behavior at follow-up. Bullying also stands out as an independent risk factor for the development of future externalizing behavior even among adolescents with accurate perceptions of bullying experiences. These specific groups of youth warrant more focused assessment and intervention.