Nonsuicidal self-injury is surprisingly common among adolescents. The exact percentage of adolescents who self-harm varies between studies. One systematic review in 2017 found that the prevalence of this behavior is between 7.5% and 46.5% of adolescents. Self-harming typically begins around 12 to 14, most to cope with stress and negative emotions and situations.

Recent research reveals what childhood behaviors may signal future self-harm and the long-term effects this habit may cause. Here’s what the current science says about nonsuicidal self-harm—and how you can help your child, patient, or patient’s child engaged in this dangerous practice.

Types of Self-Harm

A common misconception of self-harm is that it’s a suicide attempt. However, the intent of self-injury is usually to cause pain to the body, and some people even say they engage in this behavior to avoid attempting suicide.

Cutting or carving the skin with a sharp object like a knife, razor blade, or piece of glass is the most common form of self-harm. But there are many other ways that people self-harm, which varies in severity:

• Burning the skin.

• Hitting or punching oneself or other objects.

• Preventing wounds from healing by scratching or picking at scabs.

• Pulling out hair, eyelashes, or eyebrows.

• Intentionally overdosing on medications.

• Drinking something harmful like bleach or detergent.

• Biting oneself.

• Head banging (such as against a table or wall.)

• Excessive body piercing or tattooing.

• Breaking bones purposefully.

Why Do Adolescents Self-Harm?

There are many reasons why adolescents may begin to self-harm. It’s often a coping mechanism to get a handle on out-of-control emotions. Some research suggests that self-harm can temporarily release chemicals in the brain that help relieve emotional turmoil.

Adolescents may also self-harm to:

• “Feel something” (no longer feel numb.)

• Punish oneself.

• Signal distress to others.

• Reduce feelings of anxiety, sadness, loneliness, and anger.

In one 2016 study, researchers found that adolescents’ most commonly endorsed reason for self-harm was “to get relief from a terrible state of mind.”

What Drives Self-Harming Behavior?

Past research suggests that the vast majority of adolescents who self-harm have one or more mental health issues, including:

• Bipolar disorder.

• Depression.

• Anxiety.

• Eating disorders.

• PTSD.

• ADHD.

• Addiction (substance abuse.)

High impulsivity, physical or sexual abuse, neglect, issues with sexual orientation, losses (like deaths and break-ups), and trouble with the police have also been associated with self-harm.

A child’s social realm can significantly influence their self-harm risk. Low self-esteem—particularly due to bullying, body fat, and slut-shaming—places teenagers at a higher risk of self-injury. Research also suggests that viewing self-harm or suicide-related content on social media and websites increases self-harm risk, as does having peers who self-harm (that is, to an extent, it’s “contagious”.)

In a new study published in May 2021 in the Journal of the American Academy of Child and Adolescent Psychiatry, researchers used computer modeling to discover social or behavioral similarities between nearly 1,600 UK adolescents who engaged in self-harm at age 14.

They found that adolescents who self-harm fit into one of two behavioral categories:

• Those who experienced years of emotional difficulties and frequent bullying.

• Those who engage in risk-taking behavior experienced recent relationship changes with family and friends.  

Kids from both groups reported low self-esteem and difficulty sleeping at age 14.

Consequences of Self-Harming

Nonsuicidal self-harming comes with its fair share of physical, emotional, and social consequences, including:

• Pulling away from friends and loved ones increases the feelings of loneliness they may already have.

• Becoming ostracized by people who don’t understand their behaviors and struggles.

• Permanent scars.

• Infections.

• Guilt or shame.

• Decreased self-esteem.

• An addiction to self-harm (it’s likened to an opiate habit.)

There are even financial consequences to self-harming behaviors. In one 2019 study in Psychiatric Services, scientists found that adolescents admitted to the emergency department for self-harm had significantly greater emergency room visits, inpatient admissions, and inpatient costs five years later compared with other adolescents, including those admitted for mental health problems.  

A study published in May 2021 in the journal Schizophrenia Bulletin found that adolescents admitted to the hospital for self-harm have an increased risk of being diagnosed with psychotic or bipolar disorder later in life. Using data from the Finnish Birth Cohort Study from 1987 to 2015, they found that nearly 13% of adolescents and young adults who visited the hospital for self-harm treatment went on to be diagnosed with psychosis, and 9% were diagnosed with bipolar disorder. This puts them at more than six times the risk of developing psychosis and almost eight times the risk of developing bipolar disorder than peers.

How You Can Help

If you help care for adolescents, reassure them that they’re not alone (you’re there to help!) and that there is a safe end to their emotional troubles. Promote healthy ways of expressing their feelings by building trust, establishing a rapport, and teaching them how to develop healthy coping strategies, such as mindfulness meditation, peer groups, and therapy.

If you speak to a patient who brings up their child or you have an adolescent yourself, the steps are the same; the following lists can be recommendations given to another or ones to adopt on your own.

Look for self-harm warning signs, including:

• Unexplained and frequent injuries.

• Low self-esteem.

• Emotional and relationship problems.

• Difficulties in school.

• Wearing clothing such as long sleeves and pants in hot weather could signal they’re hiding injuries.

Address the issue directly with the child:

• Use a calm, respectful tone.

• Offer reassurance and comfort.

• Ask what kind of support they need.

• Don’t focus on the specific act of self-injury—instead, concentrate on the issues that may be driving the behavior.

• Focus on the child, not on placing blame or what went wrong. (If the individual intervening is having trouble with this, it may be appropriate to seek a professional to help work through these feelings separately.)

After addressing the issue with the child:

• Give praise for positive changes.

• Avoid reacting or responding if there is a “relapse.”

• Check-in regularly with open-ended questions to build healthy communication habits.

• Don’t rush progress or control your child’s behavior--it takes time.

• Suggest professional help if progress is fleeting.

It’s important to remember adolescents who self-harm are not destined to engage in this behavior for the rest of their lives or even the rest of adolescence—gentle intervention can help curb this behavior and improve psychological well-being.