Discovering that a teenager is self-harming is one of the most frightening experiences a parent can face. The instinct is often to react with alarm, to demand explanation, or to try immediately to stop the behaviour – which, while entirely understandable, can push the teenager into hiding it more effectively. What young people who self-harm typically need first is to feel heard rather than managed, and to receive help for what is driving the distress, not just for the self-harm itself.
Self-harm is not a single thing. It is a behaviour that spans a wide spectrum of severity and meaning, and the reasons behind it – the emotional experiences that make it feel necessary – vary considerably between individuals. Understanding what self-harm is and isn't, and what actually helps, is the starting point.
Healthbooq (healthbooq.com/apps/healthbooq-kids) covers mental health in teenagers and how families can support them. If you or someone you know is in immediate danger, call 999.
What Self-Harm Is
Self-harm refers to deliberate, direct injury to the body, typically without suicidal intent. The most common forms in adolescents are cutting (usually on the arms, thighs, or abdomen), burning, hitting or bruising, scratching to the point of bleeding, and pulling hair. Less common forms include swallowing objects and poisoning, which carries higher medical risk.
Self-harm is almost always a response to emotional pain that has become overwhelming. Common functions include releasing emotional tension ("it's the only way I can feel something different"); punishing oneself; feeling in control when everything else feels out of control; communicating distress that feels impossible to express in words; and, for some young people, feeling real when they feel numb or dissociated. The relief is usually temporary, and the behaviour tends to become more frequent and more severe over time if the underlying emotional difficulties are not addressed.
Matthew Nock at Harvard University has contributed significantly to the research on self-harm functions and mechanisms, finding that emotion regulation is the most commonly reported function across cultures and age groups. In the UK, Nicola Madge and colleagues at the Brunel University London Child and Adolescent Self-harm in Europe (CASE) study documented that 27% of 15-16-year-old girls and 10% of boys in England reported lifetime self-harm – among the highest rates in Europe.
Self-Harm Is Not the Same as Suicidal Intent
Most self-harm does not reflect a wish to die. This distinction is clinically important, but it does not mean self-harm should be treated as benign. Self-harm is a significant risk factor for suicide: people who self-harm have substantially higher rates of suicidal behaviour than those who do not, even when the self-harm itself is not intended as a suicide attempt. Every episode of self-harm warrants a clinical assessment that includes asking directly about suicidal ideation.
Signs that self-harm may be escalating in seriousness include: increasing frequency or severity of wounds; self-harm in multiple locations; beginning to use methods with higher lethality risk (ligatures, overdoses, drowning); significant isolation and withdrawal; expressions of hopelessness; giving away valued possessions; and direct statements about wanting to die.
How Common It Is
Population-level data from the NHS Digital Mental Health of Children and Young People surveys and from the CASE study consistently show that self-harm begins most commonly between ages 12 and 15, with girls more commonly affected than boys in terms of reported prevalence (though boys may under-report). Rates have increased over the past decade; social media is often implicated, though the relationship is complex and contested – Patti Valkenburg at the University of Amsterdam and Amy Orben and Andrew Przybylski at Oxford have both published research cautioning against simple causal conclusions.
Risk factors include pre-existing mental health difficulties (particularly depression, anxiety, eating disorders, and PTSD), adverse childhood experiences, LGBTQ+ identity (substantially higher rates), chronic physical health conditions, and family difficulties.
Responding When You Discover Self-Harm
The immediate response matters. A calm, non-panicked reaction, which communicates that the parent can hear what the young person is going through without being destroyed by it, is more helpful than visible horror or demands for explanation. Simple questions – "I've noticed you've been hurting yourself. Can you tell me what's been going on?" – open the door. Blaming, threatening, bargaining ("if you stop, I'll..."), or immediately removing potential tools (sharps, lighters) often closes it.
Physical wounds may need medical attention. A wound that is deep, won't stop bleeding, or shows signs of infection needs to be seen – by a GP or A&E, depending on severity. The clinical assessment of the wound is one thing; the emotional and psychiatric assessment is another and should follow.
If a young person discloses suicidal intent alongside self-harm, or if you find them in a medical emergency (overdose, severe wound), call 999.
Treatment
Dialectical Behaviour Therapy (DBT), developed by Marsha Linehan at the University of Washington, has the strongest evidence base for reducing self-harm in adolescents. DBT addresses the emotion dysregulation that underlies most self-harm by teaching skills across four domains: mindfulness, distress tolerance, emotion regulation, and interpersonal effectiveness. DBT-A (the adolescent adaptation) adds a family skills component. A Cochrane review by Mehlum and colleagues in 2019 found DBT-A superior to treatment as usual for adolescent self-harm.
Mentalisation-Based Treatment for Adolescents (MBT-A), developed by Peter Fonagy and colleagues at UCL, is another evidence-supported approach that targets the capacity to understand one's own and others' mental states – a capacity that is often underdeveloped in young people who self-harm.
Standard CBT, while helpful for underlying depression and anxiety, has less specific evidence for self-harm than DBT. Crisis safety planning – developing a specific, concrete plan for what the young person will do when the urge to self-harm arises – is a useful element of any intervention.
CAMHS referral via GP is the standard route. For immediate crisis support, the Samaritans helpline (116 123) is available 24 hours a day and will talk to young people. Papyrus (0800 068 4141) specifically supports young people at risk of suicide. MIND and Young Minds provide information and support for young people and their families.
If you are supporting a teenager who is self-harming and you are concerned about their immediate safety, call 999 or take them to A&E. Samaritans (116 123) are available 24 hours a day.
Key Takeaways
Self-harm in teenagers – most commonly cutting, but also burning, hitting, or other self-injury – is more prevalent than many parents realise, affecting approximately 25% of young people at some point during adolescence according to UK data. It is usually a coping mechanism for emotional distress rather than an attempt to die, though it is a significant risk factor for suicide and should always be taken seriously. The most important responses are a calm, non-judgmental reaction and access to mental health support. Dialectical Behaviour Therapy (DBT) has the strongest evidence base for reducing self-harm in adolescents.
