The Science Behind Why Some People Harm Themselves

Rose: “They’re people?”
Doctor: “They were, until they had all their humanity taken away. That’s a living brain jammed inside a cybernetic body, with a heart of steel. All emotions removed.”
Rose: “Why no emotions?”
Doctor: “Because it hurts.” —“Doctor Who”

In A Nutshell

Inflicting pain to feel better seems like a complete contradiction to many people. But studies on the practice of self-harm have found that in those that do practice non-suicidal self-injury (NSSI) there’s a correlation between the application of physical pain and a lessening of activity in the parts of the brain that govern negative emotions. Others tap into something a little different—the relief that they feel when the pain of their injury is removed. It’s pain they can control, and that’s what makes it attractive.

The Whole Bushel

Everyone has their own way of dealing with stress. Admittedly, some ways are healthier than others. Different people process different emotions in different ways, and for some people, their way of handling stress is something that others find unthinkable—self-harm and cutting.

A huge number of people cut themselves as a way of dealing with stress or emotional pain, and for those people, it provides a measure of relief that they typically don’t find anywhere else. That makes it an incredibly powerful thing, and when something works, we tend not to want to stop doing it.

Cutting and other kinds of self-harm techniques are called non-suicidal self-injury, or NSSI. The popular opinion of the practice has long been one that’s a bit skeptical. It’s fairly common for friends and family to wonder if a person is just using NSSI for attention or manipulation. It’s certainly possible that some people do that, but recent study is showing there’s a legitimate biological component as well.

Ask someone who does it why they do it, and chances are they’ll give you a very simple explanation: It helps them relieve some of the pain that they’re feeling elsewhere. That seems at odds with what they’re doing. Inflicting pain seems like it should be a negative thing, but it’s getting the opposite reaction in some people.


A couple different things could be at work. One possibility is that it’s not the pain of cutting that provides the relief, but the aftermath. It’s when the pain stops that there’s an overwhelming relief, and it’s pain that can be controlled. In some cases, it might be the removal of the painful stimuli that triggers a pleasurable sensation in the brain.

One study that looked at people with a history of NSSI found that when put in a situation that mimicked the pain-and-release of self-harm (the application of heat), the presence of pain lessened activity in certain parts of the brain. Those parts are the ones that are typically associated with the presence and processing of a negative emotion, suggesting that for those who self-harm, there is a biological connection between the application of physical pain and the release of an emotional one.

Others say that the pain of cutting is a distraction from a larger pain, and having that smaller, more urgent, and ultimately removable physical pain is easier than dealing with a larger emotional one. As early as the 1980s, addiction to self-harm was found to be little different from addiction to drugs or other substances. The more it’s done, psychologists say, the bigger an effect it seems to have on the body’s opioid system. That’s the part of the nervous system that control the body’s reaction to pain, pleasure, and addiction.

And it’s a shockingly common behavior, with an estimated 12–23 percent of adolescents having participated in some kind of self-harm activity. About 60 percent of those are women, and many practitioners are under the age of 20.

Self-harm also wears a lot of different disguises, and it’s not just the common cutting or burning. According to the National Health Service, excessive exercise, anorexia, binge eating, alcohol or drug use, punching and hitting, or taking poisonous substances can also be the method of choice for self-harming individuals.

Show Me The Proof

Scientific American: How Pain Can Make You Feel Better
Boston University: Cutting: The Self-Injury Puzzle
National Institutes of Health: Neural correlates of antinociception in borderline personality disorder
National Health Service: Self-harm