Scars, burn marks, and teens who wear long-sleeved shirts in 90 degree weather – what do they have in common? Hint, it’s a behavior that is reported by one support group to affect up to 20 percent of adolescents. The answer? Self injury.
Self-injury, which often takes the form of cutting and primarily occurs in adolescents, is nothing new. In fact, according to Matthew Nock, Ph.D, self injury has been around for thousands of years but it has only recently been looked at closely by mental health researchers.
A professor of psychology and director of the Laboratory for Clinical and Developmental Research at Harvard University, Nock heads a team of graduate students working to understand the reasons anyone would engage in self-injurious behaviors. He recently edited a book on the subject, “Understanding Nonsuicidal Self-Injury: Origins, Assessment, and Treatment,” a comprehensive overview of the known research and treatment recommendations available. He spoke with New England Psychologist’s Catherine Robertson Souter about his team’s research and reasons why this behavior seems to have grown.
Q: When we talk about self-injury, we usually think of cutting. What are the other behaviors that fall under the same category?
A: Cutting is the form of the behavior we see most often, probably about 70-75 percent of the time. We also see people who burn their skin, insert objects under their skin, scratch their skin to the point of drawing blood, bang their head or punch themselves.
Usually people don’t just use one method; most often they use cutting and some other method or combination of methods.
Q: Do we have any idea if it is increasing?
A: We don’t. The study of it is increasing and the anecdotal reporting of it is increasing. If you talk to clinicians, nurses, teachers, guidance counselors or physicians, they see it a lot more now than they did 20 years ago. But there have been no good longitudinal data of self injury. We just don’t know long term what the prevalence of the behavior has been.
Q: You work primarily with the normally-developed population but you have found a link between these people and those with developmental disabilities?
A: We drew heavily from what’s been learned from kids with developmental disabilities to create a model to understand self injury. There is literature in that area suggesting that the behavior serves an internal regulation function and a social regulation function. We wondered if the behavior might serve the same function in both groups.
These different areas have been studied and conceptualized as fairly distinct because these things look very different – the teenage girl who cuts herself versus the autistic boy who bangs his head against the wall.
What our work suggests is that, although the form looks different, it may serve the same function, emotional or cognitive regulation. Most often it decreases or stops bad thoughts or feelings. And there is also an element of social regulation – it serves as a help-seeking function.
Q: When you say that self injury serves a regulation function, helping to reduce negative thoughts or feelings, does that mean there is an actual physical change in the body?
A: That is what we are trying to understand. Most of the data so far has been based on self-report. The primary reason people give is that they had bad thoughts or feelings and, after cutting or burning, these things decrease. About a quarter of the time, people say it’s for feeling generation, which is the opposite. It’s “I feel nothing so I cut myself and I feel something and that is reinforcing to me. I feel alive, I feel sensation.”
The first, that self injury decreases aversive thoughts or feelings, is something we’re trying to figure out. Is it simply distraction that you have bad thoughts or feelings and pain demands attention? What is the physiological mechanism?
We have new data that we haven’t published yet. We are doing a study using ambulatory monitoring, where we have people wear physiological recording equipment while they go out into the world and engage in self injury. What we see are big increases in arousal right before self injury and a pattern that suggests self-soothing right after the behavior.
Q: Could that be in anticipation of the cutting/self injury – or is that why they do it?
A: We believe it’s why they cut. The one big limitation of doing work in this area is that we can’t do experiments to increase self injurious thoughts or behaviors. A lot of data we have are observational – so when you use observational data you always want to be careful not to make causal inferences.
We find a similar pattern when people engage in other coping strategies, like smoking a cigarette or going for a walk or using mindfulness skills. We’ll see an increase in arousal right before and decreased right afterwards.
Q: What else are you working on?
A: We have also done lab studies where we collect physiological data on two groups participating in a distressing task. We see significantly higher arousal in self injurers suggesting real differences between them and those who do not self injure.
And the self-injurers choose to escape from the task significantly sooner than do non injurers suggesting trouble with distress tolerance. So, what we are seeing is both higher arousal and a poorer ability to tolerate it.
Q: Not everyone with painful feelings or thoughts wind up cutting or burning themselves. Why do these people?
A: People often engage in harmful behaviors for the same reasons but different behaviors can serve the same functions. You could drink, use drugs, cut yourself or you can go for a jog. The question is what leads people to engage in maladaptive behaviors and why pick one over another? That is what we are studying.
One thing we think is that peer influence and social learning play a role. If your friends use drugs or drink, you are more likely to. That may be why we are seeing an increase in self injury. People are exposed to more of it online, in the media. It has become more prominent in the public awareness.
We also think that if you are very self critical or believe that you deserve to be punished, that may lead you to choose self injury rather than some other less directly harmful behavior.
Q: What is next for your research?
A: We want to test the role of social and peer influences and also people’s implicit associations with self injury, to see how “good” or “bad” they perceive it to be and does that influence whether they engage in it. We want to understand the association between pain and self punishment, the things we don’t understand very well.