1. Center for Disease Control. Web-Based Injury Statistics Query and Reporting System (WISQARS). Atlanta: National Center for Injury Prevention and Control; 2019.
3. Sheridan DC, Johnson KP, Fu R, Spiro DM, Hansen ML. Impact of an inpatient psychiatric unit on pediatric emergency mental health care. Pediatr Emerg Care 2017;33:1-4.
4. Mapelli E, Black T, Doan Q. Trends in pediatric emergency department utilization for mental health-related visits. J Pediatr 2015;167:905-910.
6. Leon SL, Cloutier P, Polihronis C, Zemek R, Newton AS, Gray C, et al. Child and adolescent mental health repeat visits to the emergency department: a systematic review. Hosp Pediatr 2017;7:177-186.
7. Rottenberg J, Wilhelm FH, Gross JJ, Gotlib IH. Respiratory sinus arrhythmia as a predictor of outcome in major depressive disorder. J Affect Disord 2002;71:265-272.
8. Tsypes A, James KM, Woody ML, Feurer C, Kudinova AY, Gibb BE. Resting respiratory sinus arrhythmia in suicide attempters. Psychophysiology 2018;55:10.
9. Chesin M, Cascardi M, Tsang W, Smith S. Blunted arousal in response to psychological stress is associated with current suicide ideation. Arch Suicide Res 2020;24(sup2):S381-S390.
11. Wilson ST, Chesin M, Fertuck E, Keilp J, Brodsky B, Mann JJ, et al. Heart rate variability and suicidal behavior. Psychiatry Res 2016;240:241-247.
12. Forkmann T, Meessen J, Teismann T, Sütterlin S, Gauggel S, Mainz V. Resting vagal tone is negatively associated with suicide ideation. J Affect Disord 2016;194:30-32.
13. Schafer A, Vagedes J. How accurate is pulse rate variability as an estimate of heart rate variability? A review on studies comparing photoplethysmographic technology with an electrocardiogram. Int J Cardiol 2013;166:15-29.
14. Scholkmann F, Boss J, Wolf M. An efficient algorithm for automatic peak detection in noisy periodic and quasi-periodic signals. Algorithms 2012;5:588-603.
15. Gipson PY, Agarwala P, Opperman KJ, Horwitz A, King CA. Columbia-suicide severity rating scale: predictive validity with adolescent psychiatric emergency patients. Pediatr Emerg Care 2015;31:88-94.
17. Andrews JA, Lewinsohn PM. Suicidal attempts among older adolescents: prevalence and co-occurrence with psychiatric disorders. J Am Acad Child Adolesc Psychiatry 1992;31:655-662.
19. Chang HA, Chang CC, Chen CL, Kuo TB, Lu RB, Huang SY. Heart rate variability in patients with fully remitted major depressive disorder. Acta Neuropsychiatr 2013;25:33-42.
20. Koenig J, Kemp AH, Beauchaine TP, Thayer JF, Kaess M. Depression and resting state heart rate variability in children and adolescents - A systematic review and meta-analysis. Clin Psychol Rev 2016;46:136-150.
21. Schiweck C, Piette D, Berckmans D, Claes S, Vrieze E. Heart rate and high frequency heart rate variability during stress as biomarker for clinical depression. A systematic review. Psychol Med 2019;49:200-211.
22. Adolph D, Teismann T, Forkmann T, Wannemüller A, Margraf J. High frequency heart rate variability: Evidence for a transdiagnostic association with suicide ideation. Biol Psychol 2018;138:165-171.
23. Jelinek HF, Khandoker AH. Reducing suicidal ideation by biofeedbackguided respiration - heart rate coherence. Digit Psychiatry 2020;3:1-11.
24. Lewis GF, Hourani L, Tueller S, Kizakevich P, Bryant S, Weimer B, et al. Relaxation training assisted by heart rate variability biofeedback: Implication for a military predeployment stress inoculation protocol. Psychophysiology 2015;52:1167-1174.
25. Park SM, Jung HY. Respiratory sinus arrhythmia biofeedback alters heart rate variability and default mode network connectivity in major depressive disorder: a preliminary study. Int J Psychophysiol 2020;158:225-237.
26. McAusland L, Addington J. Biofeedback to treat anxiety in young people at clinical high risk for developing psychosis. Early Interv Psychiatry 2018;12:694-701.
27. Goessl VC, Curtiss JE, Hofmann SG. The effect of heart rate variability biofeedback training on stress and anxiety: a meta-analysis. Psychol Med 2017;47:2578-2586.
28. Hernando D, Roca S, Sancho J, Alesanco A, Bailon R. Validation of the apple watch for heart rate variability measurements during relax and mental stress in healthy subjects. Sensors (Basel) 2018;18:2619.
29. Pestian JP, Sorter M, Connolly B, Bretonnel Cohen K, McCullumsmith C, Gee JT, et al. A machine learning approach to identifying the thought markers of suicidal subjects: a prospective multicenter trial. Suicide Life Threat Behav 2017;47:112-121.