Non- (NSSI) is alarmingly common among teenagers and young adults around the globe. Over the past decade, the statistics on the prevalence of NSSI have varied from study-to-study. Most recently, a report from last year (Monto et al., 2018) on the prevalence of NSSI among a representative sample of US adolescents (in different states) found that rates of self-harm ranged from 6.4% to 14.8% for boys and 17.7% to 30.8% for girls. For this survey, adolescents were asked to self-report “purposefully hurting themselves without wanting to die over the past 12 months."

Another UK-based study (Taylor et al., 2018) from last year investigated NSSI frequency among Lesbian, Gay, Bisexual youth and found that LGB youth are at a much higher risk of non-suicidal self-injury and suicide than their heterosexual peers. This self-harm study reported that almost two-thirds of LGB students in their early 20s had carried out some form of non-suicidal self-injury over their lifetime. Additionally, over one-third of the LGB students in this survey reported an attempted suicide in their lifetime compared to 14 percent for non-LGB students.

Despite the prevalence of self-injury among teenagers and young adults, until now, there’s been a scarcity of research on how perceptions of pain play into NSSI dynamics. Nevertheless, experts speculate that how people who intentionally hurt themselves experience pain in relation to emotional distress may be a driving force behind self-injury behaviors.

Currently, there is one school of thought which posits that people who purposely hurt themselves use physical pain as a way to distract their minds from thinking about emotional distress. Another hypothesis is that during acts of non-suicidal self-injury those who are feeling emotionally shut-down and numb in their daily lives inflict self-harm as a way to feel something.

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In an attempt to figure out the role that pain plays during self-harm among adolescents and young adults, researchers at Rutgers University recently developed a smartphone app that collects self-reported data on self-injury episodes throughout someone's day-to-day life. This paper, “The Dynamics of Pain During Nonsuicidal Self-Injury,” is currently available online and will be published March 2019 in the journal Clinical Psychological Science.

For this study, first author Edward Selby, an associate professor of psychology at the Rutgers Institute for Health, Health Care Policy and Aging Research, and colleagues recruited a cohort of 47 volunteers between the ages of 15 and 21 who regularly hurt themselves — at least once a week. Selby is also the director of Rutgers Emotion and Psychopathology (EmP) Lab.

Notably, almost 70 percent of the participants in this study were female, which is a reflection of the higher incidence self-injury among females, according to the researchers. None of the study participants had been diagnosed with a mental health disorder and none of the NSSI-study participants were at risk of suicide.

Using the smartphone app that was specifically designed for this study by the research team, participants described each specific self-injury behavior (e. ., cutting, burning, , punching, biting, or head banging) and its duration of time.

Participants in this smartphone-app-based study also used a pain-rating scale of 0 (no pain) to 10 (extremely painful) to report how much each self-injury episode hurt. Additionally, the app asked them to rate how strongly they were feeling each of 21 different emotions before, during, and after each self-injury episode. The emotion options ranged from angry, sad, , and overwhelmed, to feeling , etc.

"The experience of pain during non-suicidal self-injury remains a mystery and can be difficult for clinicians and families to understand because it challenges our assumption that people want to avoid or minimize pain," Selby said in a statement. "However, people who engage in this behavior intentionally and repeatedly inflict physical injury on themselves despite — or perhaps because of — the physical pain it elicits."

Interestingly, of 143 self-injury episodes that were tracked by the smartphone app, most participants self-reported feeling significant pain when they started to harm themselves. The combination of high negative emotions at the onset of a self-injury episode and low amounts of pain experienced during the episode tended to result in a longer duration of repeated acts of self-harm within the episode.

Also, if someone reported high negative emotions and felt less pain during each episode, he or she was as at higher risk of having more overall self-injury episodes during a two-week tracking period. In their paper, the authors sum up, “The evidence supports a dynamic experience of pain during self-injury that can vary between people and episodes.”

In an email exchange, Edward Selby explained: "We found that if people were very distressed, and they rated lower pain during the NSSI event, then they tended to injure themselves multiple times during that episode. Essentially we think this effect was due to a desire to try and elicit more pain via self-injuring further."

"These findings suggest that the individuals who had high emotional distress and instability sought to use physical pain from self-injury more frequently to relieve their emotional distress," Selby continued. "It also shows that an absence of pain sensation during self-injury may arise as the behavior worsens and can lead these individuals to be less motivated to seek help."

The Rutgers researchers believe their app-based findings show that adolescents and young adults who are prone to self-injury experience pain differently. The study "shows people who hurt themselves experience pain differently and that clinicians should examine their experiences with pain to understand why they started injuring and predict how frequently they may hurt themselves in the future,” a statement from Rutgers on this study concluded.

First-Person Account of Pain Dynamics and Emotional Distress in and Beyond

Although I've never inflicted self-harm in any of the ways that Selby et al. tracked using a smartphone app in this study, I have used daily exposure to physical pain during vigorous exercise as a psychological coping mechanism since high school. Anecdotally, as a gay teen, when I was going through a period of clinical during adolescence, I used very high-intensity aerobic exercise as a way to feel something.

Source: Courtesy of Kiehl's Since 1851

When I first started jogging at age 17, I felt hollow and dead inside from symptoms of clinical depression. Running pierced through my numbness and made me feel alive. Surprisingly, the excruciating pain of six-minute-mile marathon-long runs made me feel really good. As a professional , I have a hunch that my secret weapon for outperforming others in grueling races was that a masochistic part of me derives pleasure from physical pain.

For example, as an extreme athlete, the physical pain of having my feet covered in blisters while running 135-miles nonstop through Death Valley (where temperatures can reach 130ºF) was "kids' stuff" compared to the ouch-factor and psychological torture of being ostracized by classmates and bullied by my high school dean during adolescence.

Hypothetically, I wonder: Are exercise-based interventions using high-intensity interval training (HIIT) an underutilized way to help adolescents and young adults who are prone to inflict self-injury tap into pain dynamics that provide psychological relief without causing bodily harm?

During our email exchange, I asked Edward Selby if his lab has explored any links between aerobic exercise, pain dynamics, and self-injury or if he thought HIIT training might be worth investigating as a possible way to curb harmful self-injury. He responded, "Exercise at an appropriate fitness level may be a powerful behavioral replacement for self-injury, as it involves intense physical sensations that can distract from emotional distress. In fact, activities such as HIIT can both physically distract from emotional distress and help channel emotional energy into a safe and healthy outlet, reducing the need for self-injury."