A note on editorial approach This article addresses self-harm. Methods are not described. Self-harm is characterized as a "functional coping strategy" for emotion regulation — the aim is description, not justification or promotion. The mandatory reporting obligation is explained from the perspective of a parent who is the person who noticed a problem. A list of resources appears at the end.
Lead
When a parent notices the injuries, they are often left holding a single question: why? And at the same time, they hesitate to put that question directly to the child — afraid of getting angry, afraid of pushing too hard, unsure what words to use.
Self-harm can be understood not as a "problem behavior" but as an SOS signal when emotion regulation breaks down. Starting from that understanding changes how the "why" gets asked — and opens a channel through which the child may be able to speak.
Non-Suicidal Self-Injury (NSSI): Definition and Function
The DSM-5-TR Framework
NSSI: Non-Suicidal Self-Injury: deliberate self-harm to one's own body tissue without intent to die, functioning as an emotion-regulation strategy (Non-Suicidal Self-Injury) is defined as the deliberate, direct injury of one's own body tissue in the absence of suicidal intent [3]. It is categorically distinct from a suicide attempt — the person is not trying to die; rather, self-injury is often functioning as a way to keep going.
That said, NSSI is associated with elevated long-term suicide risk [1], which means "there's no suicidal intent so we're safe" is not a judgment parents should rest on.
The Emotion-Regulation Mechanism
Why does injuring one's own body serve an emotion-regulation function? Research points to several explanations, but a prominent one is this: the invisible pain of overwhelming emotion is converted into visible, locatable physical pain, providing a sense of control and a concrete sensation [1]. In other cases, self-injury functions as stimulation to break through a dissociative state — a feeling of being blurred, numb, or disconnected.
The question "why would you do that?" is rarely productive, because the child usually cannot articulate a "why." The body has learned self-injury as a form of emotional regulation, and it emerges impulsively.
Onset Age and Prevalence
The lifetime prevalence of NSSI in adolescent populations is reported at 17–18% [2] — not rare. The peak age of first occurrence is 12–14 years, but cases beginning at 10–11 years are increasingly reported. The upper years of primary school should be recognized as a window when first onset can occur.
Trichotillomania: a disorder characterized by recurrent, compulsive urges to pull out one's own hair, classified in the OCD spectrum — recurrent pulling out of one's own hair — is classified within the obsessive-compulsive spectrum and has an estimated point prevalence of 0.5–2%. It is far more common in women among adults (roughly 4:1), but in childhood the sex ratio has been reported as about equal [5]. It is not identical to self-injury, but the two often share a common axis of difficulty with emotion regulation.
PTSD in Children: The Symptom Profile
Criteria at Age 6 and Above
DSM-5-TR sets separate diagnostic criteria for PTSD in children younger than 6 and those 6 and older [3]. Criteria for children 6 and above largely mirror adult criteria, but how symptoms manifest varies by age.
- Re-experiencing: nightmares (content may not be explicit), reenactment of traumatic scenes during play, intrusive memories (flashbacks)
- Avoidance: avoidance of specific places, topics, or activities; emotional numbing
- Hyperarousal: overreaction to minor stimuli, difficulty sleeping, exaggerated startle response (hypervigilance)
"Reenactment in play" is a child-specific form of re-experiencing. It can appear as a child repeatedly acting out abuse scenarios during imaginative play. When a parent or caregiver notices a child returning repeatedly to the same play theme and wonders why, the content of that play is worth paying careful attention to.
Complex PTSD (ICD-11)
When repeated exposure to abuse, neglect, or domestic violence — rather than a single incident — underlies the presentation, the appropriate framework is C-PTSD: Complex PTSD: a distinct ICD-11 diagnosis for trauma from prolonged exposure, adding self-organization disturbances to standard PTSD criteria (Complex PTSD) [7]. ICD-11 lists it as a distinct diagnosis, adding disturbances in self-organization — difficulty regulating emotion, negative self-concept, and problems in relationships — on top of the standard PTSD symptom cluster.
Experiencing a traumatic event is not unusual in childhood. A US study that followed about 1,400 community children to age 16 found that more than two thirds had experienced at least one traumatic event, yet fewer than 0.5% met full PTSD criteria; post-traumatic stress symptoms were most likely after multiple traumas or in children with prior anxiety [4]. That repetition matters more than a single event is the same idea that underlies Complex PTSD.
The state of "I'm worthless," "I can never trust anyone," "I can't control my feelings" can be understood not as a character flaw but as a neurobiological adaptation.
A Note on Mandatory Reporting of Child Abuse
Reporting suspected child abuse is not exclusively a task for medical or social welfare professionals.
In Japan, Article 6 of the Act on the Prevention of Child Abuse (Jido Gyakutai Boshi-ho) imposes on every person — not just professionals — an obligation to report to the municipality, welfare office, or child guidance center (jido sodan-sho) when they discover a child they believe may be experiencing abuse [6]. The legal threshold is low: "believed to be occurring" is sufficient — no certainty is required.
Internationally, mandatory reporting laws vary by jurisdiction, but in most countries there is at least a strong moral and social expectation — and often a legal obligation for professionals — to report suspected abuse. If you are unsure of the rules in your country, a call to a child protection helpline (see resources below) will clarify.
A report is not an arrest. The receiving agency verifies the facts and connects the child with needed services. Reporter identity is in most cases protected. The fear that "reporting will destroy the family relationship" is understandable, but it must be weighed against the risk of leaving a child in danger through inaction.
When parents themselves — not professionals — suspect abuse in a friend's child, an acquaintance's child, or their child's friend, the first step is to contact the local child welfare authority without delay.
Practical Steps When You Notice Self-Harm
When you discover self-injury, these initial steps are a useful guide:
- Receive it calmly: Not "why would you do that?" but "I noticed. I'd like you to talk to me."
- Check physical safety: Assess the injury; if medical attention is needed, address that first
- Don't carry this alone: Contact a school counselor, the child's pediatrician, or the resources listed below before the end of the day
When self-harm is recurring, DBT: Dialectical Behavior Therapy: a structured therapy teaching emotion regulation, distress tolerance, mindfulness, and interpersonal skills (Dialectical Behavior Therapy) adapted for adolescents has reduced self-harm more than usual care or supportive therapy in randomized controlled trials of teens who self-harm repeatedly [8][9] (one trial found the between-group difference had narrowed six months after treatment ended [9]). Connecting with a specialist is important, but the most common barrier to doing so is the hesitation: "Is this really serious enough for a psychiatrist?" If you are uncertain, seek a consultation — this is the position specialists consistently take.
From a parenting-records perspective, keeping a log of circumstances before and after self-harm, changes in the child's behavior, and shifts in daily life aids the specialist by providing concrete information. "When was the first time I noticed?" "Is there anything I can point to as a trigger?" — a record of what happened and when makes those answers more precise.
Summary
Self-harm arises as an SOS when emotion regulation fails. It is not a behavior to be corrected through scolding or restriction. First onset in the upper years of primary school is an increasing trend. PTSD and self-harm are connected along the same axis — the difficulty of regulating emotion.
What a parent who notices self-harm should do above all: not carry it alone. Resources exist.
Resources
- Childhelp National Child Abuse Hotline (US): 1-800-422-4453 (24 hours)
- Child Line (UK): 0800 1111 (free, 24 hours, for children and young people)
- Kids Helpline (Australia): 1800 55 1800 (24 hours)
- Children's Human Rights Hotline (Japan): 0120-007-110 (free; weekdays 08:30–17:15, Ministry of Justice)
- 189 (Ichihayaku) (Japan): National Child Guidance Center hotline (24 hours, free)
- Your child's pediatrician or school counselor: usually the most accessible first contact
References
- Nock MK. Self-injury. Annu Rev Clin Psychol. 2010;6:339–363. doi:10.1146/annurev.clinpsy.121208.131258. PMID: 20192787
- Swannell SV, Martin GE, Page A, Hasking P, St John NJ. Prevalence of nonsuicidal self-injury in nonclinical samples: systematic review, meta-analysis and meta-regression. Suicide Life Threat Behav. 2014;44(3):273–303. doi:10.1111/sltb.12070. PMID: 24422986
- American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 5th ed., Text Revision (DSM-5-TR). Washington DC: APA; 2022.
- Copeland WE, Keeler G, Angold A, Costello EJ. Traumatic events and posttraumatic stress in childhood. Arch Gen Psychiatry. 2007;64(5):577–584. doi:10.1001/archpsyc.64.5.577. PMID: 17485609
- Grant JE, Chamberlain SR. Trichotillomania. Am J Psychiatry. 2016;173(9):868–874. doi:10.1176/appi.ajp.2016.15111432. PMID: 27581696
- Act on the Prevention of Child Abuse (Jido Gyakutai no Boshi nado ni kansuru Horitsu). Law No. 82 of 2000, as amended. Article 6.
- World Health Organization. ICD-11: International Classification of Diseases, 11th Revision. Geneva: WHO; 2019. Code 6B41 (Complex PTSD).
- Mehlum L, Tørmoen AJ, Ramberg M, Haga E, Diep LM, Laberg S, et al. Dialectical behavior therapy for adolescents with repeated suicidal and self-harming behavior: a randomized trial. J Am Acad Child Adolesc Psychiatry. 2014;53(10):1082–1091. doi:10.1016/j.jaac.2014.07.003. PMID: 25245352
- McCauley E, Berk MS, Asarnow JR, Adrian M, Cohen J, Korslund K, et al. Efficacy of dialectical behavior therapy for adolescents at high risk for suicide: a randomized clinical trial. JAMA Psychiatry. 2018;75(8):777–785. doi:10.1001/jamapsychiatry.2018.1109. PMID: 29926087