Adolescent-Caregiver Agreement Regarding the School Bullying and Cyberbullying Involvement Experiences of Adolescents with Autism Spectrum Disorder.

School bullying and cyberbullying victimization and perpetration are prevalent in adolescents with autism spectrum disorder (AASD). However, the levels of adolescent-caregiver agreement regarding the bullying involvement of AASD and the factors associated with these levels remain to be evaluated. In the present study, we evaluated the levels of adolescent-caregiver agreement on the school bullying and cyberbullying involvement experiences of AASD and the factors associated with the levels of agreement. This study included 219 dyads of AASD and their caregivers. The school bullying and cyberbullying involvement experiences of the participating AASD were assessed using the School Bullying Experience Questionnaire and the Cyberbullying Experiences Questionnaire, respectively. Attention-deficit/hyperactivity disorder, oppositional defiant disorder (ODD), depressive and anxiety symptoms, and autistic social impairment were also assessed. AASD and their caregivers had poor to fair levels of agreement regarding the school bullying and cyberbullying victimization and perpetration experiences of AASD. Severe inattention, hyperactivity-impulsivity, ODD, depressive and anxiety symptoms, and autistic social impairment were associated with high levels of adolescent-caregiver agreement. When assessing the bullying involvement experiences of AASD, mental health professionals should obtain information from multiple sources. In addition, the factors influencing the levels of agreement should be considered.

Effects of transcranial direct current stimulation on improving performance of delayed- reinforcement attentional set-shifting tasks in attention-deficit/hyperactivity disorder rat model.

Behavioral flexibility (or set-shifting), which is regulated by the prefrontal cortex (PFC), is often impaired in patients with attention-deficit/hyperactivity disorder (ADHD), which is characterized by poor inhibitory control and reinforcement learning. Transcranial direct current stimulation (tDCS) has been proposed as a means of noninvasive brain stimulation and a potential therapeutic tool for modulating behavioral flexibility. Animal studies can pave the way to know if tDCS application can potentially benefit rule- and goal-based activities in ADHD. Spontaneously hypertensive rats (SHRs) and inbred Wistar-Kyoto (WKY) rats were used as an animal model of ADHD and controls, respectively, and their strategy set-shifting abilities, including initial discrimination, set-shifting, and reversal learning tasks under 0-s or 15-s reinforcer delivery delay conditions, were evaluated. The tDCS treatment had a limited effect on the performance of the SHRs and WKY rats in initial discrimination task under 0-s delay condition. Under the 15-s delay condition, the SHRs had longer lever-press reaction times and/or more trial omissions than the WKY rats did when completing set-shifting and reversal-learning tasks. Among the SHRs, tDCS treatment improved the rats' reaction times and/or reduced their trial omissions in the set-shifting and reversal-learning tasks. Although tDCS may improve delayed reinforcement learning set-shifting performance in SHRs, further studies are required to clarify the responsible mechanism.

Mother-Child Interaction of Boys With ADHD: A Behavioral Observation Study.

PURPOSE: Investigate the quality of mothers' interactions with children with ADHD and a marginal disturbance in socioemotional competence (MDSC). RESEARCH METHODS: A total of 49 mother-boy dyads were included, and we observed their communication on neutral and conflict topics for children with ADHD and MDSC, children with ADHD alone, and children with typical development (TD). The Chinese version of the Specific Affect Coding System 20-code was used to examine the affective presentation in communication. RESULTS: Mothers of children with ADHD and MDSC had less negative disengagement affect compared with those of children with ADHD alone. Boys with ADHD and MDSC and boys with TD had constant positive engagement between neutral and conflict conditions in parent-child interaction. Boys with ADHD and MDSC had significantly less positive affect and more neutral affect than children with ADHD only. CONCLUSIONS AND IMPLICATIONS: Boys with ADHD and MDSC and their mothers had worse quality of observed mother-child communication than children with ADHD only and their mothers.

Cooperative Behavior Evokes Interbrain Synchrony in the Prefrontal and Temporoparietal Cortex: A Systematic Review and Meta-Analysis of fNIRS Hyperscanning Studies.

Single-brain neuroimaging studies have shown that human cooperation is associated with neural activity in frontal and temporoparietal regions. However, it remains unclear whether single-brain studies are informative about cooperation in real life, where people interact dynamically. Such dynamic interactions have become the focus of interbrain studies. An advantageous technique in this regard is functional near-infrared spectroscopy (fNIRS) because it is less susceptible to movement artifacts than more conventional techniques like electroencephalography (EEG) or functional magnetic resonance imaging (fMRI). We conducted a systematic review and the first quantitative meta-analysis of fNIRS hyperscanning of cooperation, based on thirteen studies with 890 human participants. Overall, the meta-analysis revealed evidence of statistically significant interbrain synchrony while people were cooperating, with large overall effect sizes in both frontal and temporoparietal areas. All thirteen studies observed significant interbrain synchrony in the prefrontal cortex (PFC), suggesting that this region is particularly relevant for cooperative behavior. The consistency in these findings is unlikely to be because of task-related activations, given that the relevant studies used diverse cooperation tasks. Together, the present findings support the importance of interbrain synchronization of frontal and temporoparietal regions in interpersonal cooperation. Moreover, the present article highlights the usefulness of meta-analyses as a tool for discerning patterns in interbrain dynamics.

Multiple types of harassment victimization in adolescents with autism spectrum disorder: Related factors and effects on mental health problems.

BACKGROUND/PURPOSE: This study examined the prevalence and related factors of multiple (two or three) types of harassment victimization, including school bullying, cyberbullying, and teacher harassment, and their cumulative effects on depression, anxiety, self-esteem, and suicidality in adolescents with autism spectrum disorder (ASD) but without intellectual disability. METHODS: A total of 219 adolescents with ASD but without intellectual disability and their parents participated in this study. Their experiences of school bullying, cyberbullying, and teacher harassment were evaluated. The related factors of multiple types of harassment victimization, including demographic characteristics, socio-communicative skills, comorbid attention-deficit/hyperactivity disorder (ADHD), and oppositional defiant disorder (ODD) symptoms, were examined. Moreover, the effects of multiple types of harassment victimization on depression, anxiety, self-esteem, and suicidality were examined. RESULTS: In total, 20.54% of participants were victims of multiple types of harassment. Hyperactivity or impulsivity and ODD symptoms were positively associated with multiple types of harassment victimization. Adolescents with ASD who experienced multiple types of harassment victimization had higher severities of depression and anxiety and were more likely to have suicidality than nonvictims and those who experienced only one type of harassment victimization. CONCLUSION: Experiencing more than one type of harassment victimization was significantly associated with the development of mental health problems in adolescents with ASD. ODD and hyperactivity/impulsivity symptoms predicted the risk of experiencing multiple types of harassment.

Long-term mental health outcomes of severe burn injury: A 5-year follow-up of the 2015 Formosa Fun Coast Water Park fire disaster.

OBJECTIVE: Severe burn injuries have profound mental health impacts on individuals, such as posttraumatic stress disorder (PTSD) and major depressive disorder (MDD). Many burn survivors also report positive psychosocial changes, termed posttraumatic growth (PTG). This study investigated long-term mental health of severe burn injury (i.e., PTSD, MDD, and PTG) and the longitudinal influences of coping strategies and social support. METHODS: Ninety-nine adult burn survivors of the 2015 Formosa Fun Coast Water Park fire disaster participated in the 5-year follow-up (Wave 3, W3), with 93% completing the earlier 2- (Wave 1, W1) and 3-year follow-up (Wave 2, W2). Participants averaged 22.1 years of age at burn, and 62.6% were females. The mean total body surface area burned (TBSA) was 50.3%, with a mean length of hospital stay of 87.6 days. RESULTS: Five years after the 2015 fire disaster, 13.1%, and 14.1% of the survivors met probable DSM-5 PTSD and MDD, while 51.5% reported significant PTG. After controlling for demographic, burn-specific, and baseline outcome variables, avoidance coping at W2 prospectively predicted PTSD and depressive symptoms at W3 (p = .003 and 0.04), with medium-to-large and medium effect sizes (sr2 = 0.10 and 0.05). Approach coping at W2 prospectively predicted PTG at W3 (p = .014), with a medium-to-large effect size (sr2 = 0.07). CONCLUSION: Rates of probable PTSD and MDD were still relatively high in long-term burn survivors. However, PTG continued to be highly prevalent. Our findings highlight the importance of coping in affecting the long-term mental health of severe burn injury.

Health-related quality of life in mothers of children with attention deficit hyperactivity disorder in Taiwan: The roles of child, parent, and family characteristics.

BACKGROUND: No study has examined how child and maternal psychopathological difficulties and family factors contribute to the health-related quality of life (HRQOL) of mothers of children with attention deficit hyperactivity (ADHD). AIMS: To investigate the impact of children's diagnosis of ADHD, children's and maternal psychopathology and significant sociodemographic variables of the children, parents and family on HRQOL of mothers of children with ADHD and those of children with typical development (TD) in Taiwan. METHODS AND PROCEDURES: Children with ADHD (n = 257) and children with typical development (n = 324) and their mothers were recruited from a psychiatric clinic of a medical center and 10 elementary schools and four high schools in northern Taiwan. Maternal HRQOL was assessed with the World Health Organization Quality of Life - BREF, while the other factors were screened using the Chinese version of the Childhood Autism Spectrum Test for autistic traits, the Swanson, Nolan, and Pelham, version IV scale for ADHD symptoms, the Child Behavior Checklist for behavioral and emotional problems, The Center for Epidemiologic Studies Depression Scale for maternal depression and interpersonal problems, the Adult ADHD Self-report Scale for maternal ADHD symptoms, and the Family APGAR for family support. OUTCOMES AND RESULTS: Mothers of children with ADHD had significantly worse HRQOL in all four domains compared with those of children with typical development. Multiple regressions found that factors consistently related to the HRQOL of mothers of children with ADHD and those of children with TD were maternal depression and perceived family support after controlling for several familial, parental and child variables. HRQOL of mothers of children with ADHD and those of children with TD was more closely related to her own and family factors rather than mother- or teacher-rated ADHD symptoms, clinical diagnosis of ADHD or psychopathology of the child. CONCLUSIONS AND IMPLICATIONS: Screening for maternal HRQOL, depressive symptoms and family support systems and mental health services for mothers of children with ADHD are warranted based on these findings.

Intermittent theta burst stimulation over the posterior superior temporal sulcus for children with autism spectrum disorder: A 4-week randomized blinded controlled trial followed by another 4-week open-label intervention.

LAY ABSTRACT: Intermittent theta burst stimulation is a varied form of repetitive transcranial magnetic non-invasive brain stimulation technique used to treat several neurological and psychiatric disorders. Its feasibility and therapeutic effects on the bilateral posterior superior temporal sulcus in children with autism are unknown. We conducted a single-blind, sham-controlled parallel randomized clinical trial in a hitherto largest sample of intellectually able children with autism (N = 78). Participants randomized to the active group received two-session/week intermittent theta burst stimulation for continuous 8 weeks. Those in the sham group received two-session/week sham stimulations in the first 4 weeks and then active intervention for the following 4 weeks after unblinding. First, we found that continuous 8-week intermittent theta burst stimulation on the bilateral posterior superior temporal sulcus in children with autism is safe and tolerable. Second, we found that 8-week intermittent theta burst stimulation produced greater therapeutic efficacy, although we did not find any significant effects of 4-week intermittent theta burst stimulation on core symptoms and social cognitive performances in autism. Further analysis revealed that participants with higher intelligence and better social cognitive performance, alongside less attention-deficit hyperactivity disorder severity at baseline, were more likely to be responders. This study identified that the factors contribute to responders and the results suggest that longer courses of non-invasive brain stimulation may be needed to produce therapeutic benefits in autism, with consideration of heterogeneous responses.

Contextual Factors Impact the Variability in ADHD Symptoms in Preschoolers with Situational Hyperactivity.

Objective: This study examined preschoolers with teacher-reported or parent-reported situational hyperactivity, and whether they differed in terms of behavioral problems, attentional problems, and parenting perceptions. Method: We used the Conners' Kiddie Continuous Performance Test and the Color Flanker Task to assess 99 preschoolers with pervasive high-ADHD-symptoms (42), school-situational high-ADHD-symptoms (30), or home-situational high-ADHD-symptoms (27), plus 111 preschoolers with pervasive low-ADHD-symptoms. Parents and teachers reported externalizing/internalizing behavioral problems. Parenting perceptions were measured with the Parenting Stress Index-Short Form and a parenting perceptions scale. Results: Preschoolers with school-situational high-ADHD-symptoms had deficits in attentional control. Parents of preschoolers with home-situational high-ADHD-symptoms had higher levels of parental stress and perceived their parenting to be harsher. Preschoolers with pervasive high-ADHD-symptoms had deficits in attentional control, increased parental stress, and parents with harsher parenting perceptions. Conclusion: Preschoolers with situational high-ADHD-symptoms may have different contextual risk factors related to ADHD symptoms reported by parents versus teachers.

Decreased Risk of Influenza in Child and Adolescent Patients with Attention-Deficit Hyperactivity Disorder Following Methylphenidate Treatment: A Nationwide Cohort Study in Taiwan.

BACKGROUND: Young individuals with attention-deficit hyperactivity disorder (ADHD) may have an elevated risk of influenza because of the difficulty in complying with the behavioral procedures that help protect against influenza. Moreover, the effects of sufficient methylphenidate treatment on influenza have received little attention. OBJECTIVE: This study evaluated the association between ADHD medication usage and influenza and assessed the effect of duration of ADHD treatment on the risk of influenza using a nationwide population-based database. METHODS: This study investigated methylphenidate usage and the risk of influenza among children and adolescents with ADHD. We identified 5259 young individuals aged less than 18 years who were diagnosed as having ADHD between 1996 and 2013 from the National Health Insurance Research Database of Taiwan, and we tested whether methylphenidate use affects influenza risk using Cox proportional hazard models. RESULTS: After controlling for confounding factors, the results indicated that influenza risk significantly reduced in the group of ADHD patients who were prescribed methylphenidate for 90 days and more (hazard ratio [HR]: 0.62, 95% confidence interval [CI]: 0.52-0.75, p<0.001), demonstrating a 38% reduction in the risk of influenza in this group. However, this was not observed in the group of ADHD patients who used methylphenidate for 1-90 days (HR: 0.69, 95% CI: 0.89-1.05, p=0.12). CONCLUSION: The lower incidence of influenza observed in the group prescribed with methylphenidate for a longer period highlights the importance of compliance to medication and psychoeducation with regard to ADHD management.

Validity and Reliability Study of the Chinese (Traditional) Version of the Devereux Early Childhood Assessment for Toddlers (DECA-T).

BACKGROUND: The Devereux Early Childhood Assessment for Toddlers (DECA-T), which is one of the few standardized, norm-referenced behavioral rating scales related to young children's mental health, resilience, and social-emotional development, was developed for toddlers aged between 18 and 36 months. OBJECTIVE: The aim of this study was to test the clinimetric properties of the Chinese (Traditional) version of the DECA-T (C-DECA-T) using a classical test theory analysis and an item response theory analysis. METHODS: Seventy-five community-based toddlers aged from 18 to 36 months and 50 clinic-based participants recruited in hospitals in northern Taiwan participated in this study. Social-emotional competence was assessed by the C-DECA-T and children's behavior problems were rated via the Child Behavior Checklist 1.5 to 5 (CBCL/1.5-5). Homogeneity of the C-DECA-T was assessed by Mokken analysis; sensitivity and specificity were assessed via receiver operating characteristic curve. RESULTS: The results showed the C-DECA-T demonstrated good test-retest reliability (r=0.8) and high internal consistency (Cronbach's alpha = 0.94). Inter-rater reliability between father and mother was fair (ICC = 0.46). Convergent validity of the CBCL/1.5-5 total behavior problems (r=-0.26) demonstrated acceptable psychometric performance. The overall measure of the sampling adequacy of the C-DECA-T assessed by principal component analysis was 0.93. Mokken scale analysis showed the 36-items of the C- DECA-T formed a weak unidimensional scale (Hs =0.35), supporting its construct validity. The area under curve of the C-DECA-T in prediction of social-emotional disturbance was 0.70. The optimal cutoff of the Total Protective Factor score of the C-DECA-T was a T score of 40.1 (T40.1), with a sensitivity of 95% and a specificity of 68%. Item 2 ("show affection for a familiar adult") and item 33 ("calm herself/himself") provide a good amount of information for the assessment of social-emotional strength and needs of a toddler in clinical practice. CONCLUSION: The C-DECA-T showed good psychometric properties. Our findings of high internal consistency of the three subscales and total score of the C-DECA-T suggest symptom manifestation of social-emotional competence and needs in Taiwanese toddlers is not culturally different from American toddlers. The clinimetric properties of the C-DECA-T examined by a classical test theory analysis approach and an item response theory analysis approach suggest that the C-DECA-T is a reliable and valid instrument for measuring social-emotional strength and needs in the population in Taiwan.

Cyberbullying Victimization and Perpetration in Adolescents with High-Functioning Autism Spectrum Disorder: Correlations with Depression, Anxiety, and Suicidality.

The present study examined the associations between cyberbullying involvement and sociodemographic characteristics, autistic social impairment and attention-deficit/hyperactivity disorder and oppositional defiant disorder (ODD) symptoms in 219 adolescents with high-functioning autism spectrum disorder (ASD). Moreover, the associations between cyberbullying involvement and depression, anxiety, and suicidality were also examined. Adolescents self-reported higher rates of being a victim or perpetrator of cyberbullying than were reported by their parents. Increased age and had more severe ODD symptoms were significantly associated with being victims or perpetrators of cyberbullying. Being a victim but not a perpetrator of cyberbullying was significantly associated with depression, anxiety, and suicidality. Cyberbullying victimization and perpetration should be routinely surveyed in adolescents with high-functioning ASD.

Antipsychotic use is inversely associated with gastric cancer risk: A nationwide population-based nested case-control study.

OBJECTIVE: The association between antipsychotic use and gastric cancer risk remains unclear. Therefore, this study aimed to determine the association between antipsychotic exposure and the incidence of gastric cancer. METHODS: Using a nested case-control design, a total of 34 470 gastric cancer patients and 163 430 nongastric cancer controls were identified from Taiwan's National Health Insurance Research Database between 1 January 1997 and 31 December 2013. We analyzed the data using a conditional logistic regression model to adjust for possible confounding variables. RESULTS: Antipsychotic use was independently inversely associated with gastric cancer risk after controlling for potential confounding factors including income, urbanization, medications, physical and medical illness, aspirin use, nonsteroidal anti-inflammatory drug use and triple therapy. In addition, dose-dependent trends against gastric cancer risk were also shown with individual antipsychotic compounds including thioridazine, haloperidol, sulpiride, clozapine, olanzapine, quetiapine, amisulpride, and risperidone. A sensitivity analysis showed that second-generation antipsychotics had significant dose-dependent effects in reducing the risk of gastric cancer risk in patients with and without peptic ulcer disease. CONCLUSIONS: Antipsychotic use was inversely associated with gastric cancer risk, and dose-dependent effects against gastric cancer were also seen with several individual antipsychotic compounds.

Allergic rhinitis increases the risk of incident panic disorder among young individuals: A nationwide population-based cohort study in Taiwan.

BACKGROUND: Studies have reported an association between allergy and panic disorder. However, few studies have explored the relationship between allergic rhinitis and panic disorder. Previous studies were limited by cross-sectional study designs, self-reported symptoms, absence of matched controls, and lack of consideration of the influence of steroid and comorbidities. This study aimed to explore the longitudinal association between allergic rhinitis and panic disorder in a large population-based cohort of young people. METHODS: In this study, 79,917 new cases of allergic rhinitis between 1998 and 2012 in individuals younger than 20 years were identified from Taiwan's National Health Insurance Research Database. One control (nonallergic rhinitis) per case (allergic rhinitis) was randomly selected from the remaining sample, matching for age, sex, residence, and insurance premium. Both groups were followed until the end of 2013 for incidence of panic disorder. Cox regression analysis was performed, adjusting for sex, age, residence, insurance premium, systemic steroids, asthma, atopic dermatitis, allergic conjunctivitis, attention deficit hyperactivity disorder, depression, and Charlson index. RESULTS: Allergic rhinitis was associated with a 2-fold increase in risk for panic disorder after adjustment for other variables. Additional independent risk factor of panic disorders were female sex, older age group, and depression. LIMITATIONS: Lifestyle, substance use, smoking by the patient or family members, and psychosocial stressors were not evaluated. CONCLUSIONS: Allergic rhinitis was associated with increased risk of panic disorder. Assessment and intervention of allergy rhinitis among young people with panic disorder are critical.

Self-Reported and Parent-Reported School Bullying in Adolescents with High Functioning Autism Spectrum Disorder: The Roles of Autistic Social Impairment, Attention-Deficit/Hyperactivity and Oppositional Defiant Disorder Symptoms.

The aim of this study was to examine the prevalence of self-reported and parent-reported bullying victimization, perpetration, and victimization-perpetration and the associations of autistic social impairment and attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) symptoms with bullying involvement in adolescents with high functioning autism spectrum disorder (ASD). A total of 219 adolescents with high functioning ASD participated in this study. The associations of sociodemographic characteristics, parent-reported autistic social impairment, and parent-reported ADHD and ODD symptoms with self-reported and parent-reported bullying victimization, perpetration, and victimization-perpetration were examined using logistic regression analysis. The results found that the agreement between self-reported and parent-reported bullying involvement was low. Compared with bullying involvement experiences reported by adolescents themselves, parents reported higher rates of pure bullying victimization (23.7% vs. 17.8%) and victimization-perpetration (28.8% vs. 9.1%) but a lower rate of pure bullying perpetration (5.9% vs. 9.1%). Deficit in socio-communication increases the risk of being pure victims and victim-perpetrators. Parent-reported victim-perpetrators had more severe ODD symptoms than did parent-reported pure victims.

Exploring the Variability in Reaction Times of Preschoolers at Risk of Attention-Deficit/Hyperactivity Disorder: an ex-Gaussian Analysis.

Reaction times (RTs) are typically slower and more variable in individuals with attention-deficit/hyperactivity disorder (ADHD). Analysis of the ex-Gaussian RT distribution, which is described by mu, sigma (mean and standard deviation, respectively, of the normal distribution) and tau (that of exponential distribution), reveals that individuals with ADHD do not display overall slower RTs but have a high proportion of extremely slow RTs, represented by a high tau value. Although this is a vital component for describing ADHD-related RT variability in school-aged children, adolescents, and adults, it has not been thoroughly studied at the preschool age. We assessed 65 preschoolers at risk of ADHD and 98 typically developing preschoolers with the Conners' Kiddie Continuous Performance Test (K-CPT) and parental and teacher reports of ADHD symptoms. We found that preschoolers at risk of ADHD had greater values for RT standard deviation, sigma, and tau than typically developing preschoolers at long inter-stimulus intervals (ISIs) (3 s), but not at short ISIs (1.5 s). This suggests that attention problems in preschool children may only be apparent in the tasks with a relatively slow event rate. Our study demonstrates that the ex-Gaussian tau value is essential for describing the inattentive component of task performance in preschoolers with heightened ADHD symptoms. Furthermore, the fact that the tau effect was modulated by ISI suggests that the longer duration (3 s vs. 1.5 s) is a non-optimal energetic state in preschoolers at risk of ADHD, and that this might account for the subtle attentional flaw in task performance.

Risk of ADHD After Multiple Exposures to General Anesthesia: A Nationwide Retrospective Cohort Study.

OBJECTIVE: To study the association between general anesthesia exposure before age 3 years and having a later ADHD diagnosis. METHOD: In a birth cohort, data were collected from a nationwide population database for children born between 1997 and 1999 who were exposed to general anesthesia before their third birthday. Age- and gender-matched enrollees without general anesthesia exposure were taken as the comparison. Groups were compared to identify the incidence of ADHD after age 4 and anesthesia-related predictive factors. RESULTS: Among the 1,146 exposed children, 74 ADHD cases were identified, and 158 ADHD cases were identified in 3,438 matched controls. After adjusting for comorbid conditions and possible confounding factors, if exposure on more than one occasion or ≥3 hr, an increased likelihood of having a later ADHD diagnosis was found (HR, 1.71 and 2.43, respectively). CONCLUSION: Children with multiple or ≥3 hr general anesthesia exposures before age 3 years have an increased likelihood of a later ADHD diagnosis.

Suicide risk reduction in youths with attention-deficit/hyperactivity disorder prescribed methylphenidate: A Taiwan nationwide population-based cohort study.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) youths have increased suicide risk. Nevertheless, the beneficial effects of methylphenidate (MPH) on suicide attempt have received relatively little attention. AIMS: To investigate the MPH usage and the risk of suicide attempt among ADHD youths. METHODS: We identified 84,898 youths less than 18 years old with ADHD diagnosis between 1997 and 2013 from National Health Insurance, and examined whether MPH use affected suicide attempt risk using Cox proportional-hazards models. OUTCOME AND RESULTS: Among ADHD youths, reduction of suicide risk was found in patients prescribed 90-180days of MPH after adjusting for confounding factors (hazard ratio (HR): 0.41, 95% confidence interval (CI): 0.19-0.90) and a greater reduction in those prescribed more than 180days of MPH (HR: 0.28, 95% CI: 0.17-0.48). CONCLUSIONS AND IMPLICATIONS: We observed a 59% suicide attempt risk reduction among ADHD youths prescribed between 90 and 180days and a 72% risk reduction in those prescribed more than 180days of MPH. The protective benefit observed by the group prescribed MPH for longer duration underscores the importance of psychoeducation and compliance enhancement as part of ADHD management. Indication bias is identified as a limitation of this study, and future self-case control study to investigate the association between suicide attempt and ADHD medication is suggested. WHAT THIS PAPER ADDS: This nationwide population-based cohort study showed that among ADHD youths, reduction of suicide risk was observed in patients prescribed MPH for duration 90days and longer, underscoring the importance of appropriate ADHD pharmacotherapy and enhancing drug compliance.