title: Attention-deficit hyperactivity disorder increases the risk of deliberate self-poisoning: A population-based cohort.
abstract: BACKGROUND
  Children with attention-deficit hyperactivity disorder (ADHD) may suffer marked impairment in early adulthood, increasing their risk for serious self-harmful behaviors. Deliberate self-poisoning (DSP) is the most common form of deliberate self-harm. An association may exist between ADHD diagnosis and subsequent DSP events. The purpose of study was to determine whether children and adolescents with ADHD are at a greater risk for DSP than are age-matched controls.
  
  
  METHODS
  Claims data from the Taiwan National Health Insurance Database were used to conduct a retrospective cohort analysis of emergency department visits. The study cohort contained 3685 patients with ADHD (<8years old). Each ADHD patient was frequency matched based on sex, age, urbanization, parental occupation, and index year to 10 control patients without ADHD. A Cox proportional-hazards regression model was used to estimate the risk of DSP in the ADHD and comparison cohorts.
  
  
  RESULTS
  The risk of developing DSP was significantly higher in the ADHD cohort than in the comparison cohort (P<.0001 for log-rank test). After adjusting for potential confounders, the regression model showed that the ADHD patients were at a 4.65-fold greater risk of developing DSP than the control patients were (HR=4.65, 95% CI: 2.41-8.94).
  
  
  CONCLUSIONS
  Children with ADHD are at greater risk of developing DSP. Identifying risk factors of DSP is crucial efforts to implement prevention strategies. The identification of the underlying cause of increased DSP among ADHD patients warrants further investigation.
authors.affiliation: Department of Pediatrics, China Medical University Hospital, China Medical University, Taichung, Taiwan; Graduate Institute of Integrated Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan.
authors.forename: I-C
authors.initials: IC
authors.lastname: Chou
authors.affiliation: Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan.
authors.forename: C-C
authors.initials: CC
authors.lastname: Lin
authors.affiliation: Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan.
authors.forename: F-C
authors.initials: FC
authors.lastname: Sung
authors.affiliation: Graduate Institute of Clinical Medical Science and School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan; Department of Nuclear Medicine and PET Center, China Medical University Hospital, Taichung, Taiwan. Electronic address: d10040@mail.cmuh.org.tw.
authors.forename: C-H
authors.initials: CH
authors.lastname: Kao
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications / Q000453:epidemiology / Q000523:psychology*; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D011041:Poisoning / Q000453:epidemiology / Q000209:etiology / Q000523:psychology; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D016728:Self-Injurious Behavior / Q000453:epidemiology / Q000209:etiology / Q000523:psychology*; D013624:Taiwan / Q000453:epidemiology
keywords: Attention-deficit hyperactivity disorder; Cohort study; Deliberate self-poisoning