Is Self-Injury the Same Everywhere?

A meta-analysis of 38 studies found that nonsuicidal self-injury (NSSI) is twice as prevalent in female teenagers as it is in men in North America and Europe but not in Asia.

The study, led by Fiona Moloney, MD, from the department of psychiatry at the University of Toronto, Toronto, Ontario, Canada, also found that male adolescents in Asia had a higher prevalence of NSSI than other regions. 

NSSI is defined as “deliberate self-inflicted destruction of body tissue that results in immediate damage, for purposes not culturally sanctioned and without suicidal intent.”

“There are several studies that have shown higher rates of NSSI in girls. But few to none examine if this sex difference may vary by geographical region. We wanted to explore how sex differences in NSSI differed among adolescents across the globe to generate a more nuanced understanding of how interventions for NSSI may need to be adapted according to geographical region,” said senior author, Rachel H.B. Mitchell, MD, Sunnybrook Health Sciences Centre, Toronto, speaking to Medscape Medical News.

The findings were published in JAMA Network Open.

Mitchell said that the findings highlight the existence of sex- and geographic-specific factors related to the prevalence of NSSI behaviors among adolescents around the world.

She said more research is needed to understand why its prevalence is higher among some demographics and regions than others.

“Research in this area will be foundational in developing effective interventions for all adolescents engaged in NSSI, regardless of location, sex, and gender,” she said. It can also guide suicide prevention efforts, since NSSI, although by definition is nonsuicidal, is also a predictor of later suicide attempts.

A Behavior That Crosses Border

The meta-analysis included 38 studies with 266,491 participants. 

Across 17 countries, the pooled prevalence of NSSI was 17.7%; (women:men odds ratio [OR], 1.60; 95% CI, 1.29-1.98).

NSSI was twice as prevalent among female adolescents compared with male adolescents in North America (OR, 2.49; 95% CI, 2.16-2.86) and Europe (OR, 2.08; 95% CI, 1.69-2.58) but not in Asia (OR, 1.00; 95% CI, 0.71-1.41).

“We hope this study spreads awareness that NSSI is a behavior that crosses borders and that teenagers experience it around the world,” said Mitchell. “That said, our study indicates that NSSI may not be the same experience for teenagers everywhere. The triggers may be different. The purpose or function of the behavior may be different, or the influences and exposures could be different, and these things may be different if you are a girl in the UK or a boy in Asia. We need to understand what is different and why, so that we can develop interventions that prevent and treat the behavior, no matter the sex, or gender, or region of the world.” 

Data Can Lead to Strategy

In an accompanying editorial, editorialists Ellen-ge Denton, PsyD, University of Rochester Medical Center, Rochester, New York, and Kiara Alvarez, PhD, Johns Hopkins Bloomberg School of Public Health, Baltimore, suggest approaches to address NSSI risk globally. 

These include using media and social media platforms to identify individuals who view deliberate self-harm behaviors and to detect excessive use of media in order to implement prevention strategies. 

More work with social media and media companies could also improve the use of protocols that promote healthy reporting of and action on cyberbullying, resilient life skills, removal of content depicting self-harm, and access to prevention and intervention tools like crisis hotline numbers.

They also suggest using evidence-based interventions via internet and media outlets to treat teens with NSSI.

“The study speaks to an opportunity to understand more about the regional and cultural factors that are socializing NSSI such that interventions can be appropriately designed,” said Scott McLeod, MD, developmental pediatrician and clinical associate professor at the University of Calgary, Calgary, Alberta, Canada, speaking to Medscape Medical News. 

McLeod, who was not involved in the study, added that he would like to see some benefit for the transgender community in future prevention efforts.

“One future way to build on this important work is to gather more information and understanding about NSSI in the transgender population to ensure relevant interventions are also designed to suit the driving behaviors of NSSI in this population.”

Simon B. Sherry, PhD, professor at the Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada, who was also not involved in the study, told Medscape Medical News, that much research has shown that female adolescents are more likely to engage in nonsuicidal self-injury. 

“So that does not surprise me. What is surprising is the degree to which they are more likely [to engage]. Nonsuicidal self-injury is largely a reaction to distress. Such a stark contrast indicates that there is some factor that is particularly distressing to young women. Maybe girls are more likely to struggle with self-image, are more likely to experience mental disorders like depression and anxiety or are more likely to experience adverse childhood experiences. All of these factors have been linked to increased risk of nonsuicidal self-injury,” he said. 

“Alternatively, maybe boys react to distress in different ways and are more likely to hurt others than themselves when distressed. Thankfully, there are treatments shown to effectively treat nonsuicidal self-injury, such as dialectical behavioral therapy. If someone, boy, girl, man, or woman, is struggling with self-injury, know there is hope if you reach out for help,” Sherry said. 

The study was independently supported. Mitchell reported financial relationships with the Department of Psychiatry, University of Toronto, and the Department of Psychiatry, Sunnybrook Health Sciences Centre, the American Foundation for Suicide Prevention, Alternative Funding Plan Innovation Fund, Sunnybrook Health Sciences Centre, Brenda Smith Fund, Sunnybrook Foundation, and the TD Pooler Charitable Trust Fund. McLeod and Sherry reported no relevant financial relationships.