The recently-released draft of the next edition of the DSM includes a new diagnosis: Non- , or NSSI. You can read Tracy Alderman's PT blog post about the new diagnosis here, or read the proposed criteria for NSSI here.

I remember my first psychiatry rotation, back in 1985 when I was a medical student at the University of Pennsylvania. A young woman was admitted to the psych ward. She had been cutting herself with razor blades. "Weird," I breathed. "Weird," the psychiatry resident agreed. The attending psychiatrist put her in the locked ward, on full suicide precautions. He explained to us that this behavior was a "cry for help." That's what many people thought back then. In ancient times.

Today we know better, or we think we do. Most of these girls and young women are not suicidal, and they don't want anybody to find out. They don't want to be discovered. That's why they wear long sleeves, so nobody will see their wrists; or, more often nowadays, they cut themselves on the upper inner thigh, where nobody will look. Cutting themselves with razor blades, or burning themselves with matches, becomes compulsive, almost addictive for some of these girls. There is now evidence that for at least some of these girls, this behavior triggers a release of endogenous (for a review of this evidence, please see chapter 3 of my book Girls on the Edge). Cutting delivers a kind of disembodied rush. "I felt like I was up on the ceiling, watching myself do it," one girl told me. "I was literally high."

How common is it? Much more common than it used to be. Studies from the 1990s suggested rates of 3% or lower. But more recent studies suggest that as many as one in five girls between 10 and 18 years of age are now cutting themselves with razor blades or burning themselves with matches, etc. For example, researchers at Yale University recently reported that 56% of the 10- to 14-year-old girls they interviewed reported engaging in NSSI at some point in their lifetime, including 36% in the past year. I know of no community survey of boys in any age group which approaches that kind of prevalence.

Which brings me to one of my problems with the proposed DSM-V criteria. There's no mention of differences in the presentation of self-injury. Imagine a teenage boy who's not doing well in life: he doesn't have any friends, he's not doing well in school, he spends most of his time playing first-person-shooter video games. Let's suppose this teenage boy repeatedly hits the wall with his fist during arguments with his parents. This boy would meet all the proposed DSM-V criteria for NSSI.

Now Imagine a teenage girl who secretly cuts herself with a razor blade. She's the golden girl: she's pretty, she has lots of friends, she's successful academically, she seems to be doing well. The growing prevalence of such girls among cutters is well-documented; see for example Adler and Adler (2007), who assert that these girls are exhibiting a "voluntarily chosen deviant behavior" rather than true psychopathology. I don't agree with Adler and Adler, but that's beside the point. Such a girl would also meet the proposed DSM-V criteria for exactly the same diagnosis as the boy who broke a bone in his hand when he slammed his fist into a wall. But a "loser" boy who publicly slams his fist into a wall is experiencing an inner turmoil very different from the golden girl who secretly cuts herself with a razor blade. Lumping these two together, and pretending that they have the same problem, is not likely to be productive either clinically or nosologically.

Many researchers who study self-injury have minimized gender differences in their own data. For example, in one recent survey of young people 14 to 21 years of age (Nixon et al. 2008), researchers reported that 16.9% of those surveyed had engaged in self-injury. Read the abstract of that paper: you won't find any mention of gender differences. But when you read the full text (available at no charge by clicking here), you find that 24.3% of girls were self-injuring, compared with 8.4% of the boys. You'll find those data in Table I of the paper. The authors acknowledge the finding (in a single sentence) but they do not discuss it or try to understand it. Furthermore, this study—like most studies of NSSI—conflates the boy who publicly smashes the wall with his fist with the girl who secretly cuts herself with a razor, a blurring of reality which further masks the magnitude and significance of the underlying gender differences.

The stereotype is that kids who cut themselves are . While that stereotype is usually accurate for boys, it's less reliably accurate for girls. Most boys who cut themselves are depressed, but many girls are not. Janis Whitlock and her colleagues at Cornell (Whitlock et al. 2008) found that college women injure themselves differently, and for different reasons, compared to college men. Cheng et al. (2010) recently developed a screening questionnaire to identify college students who were engaging in NSSI. They found that some of the best questions for screening the women were useless for screening the men, and vice versa. Other researchers have found that girls are more likely than boys to self-injure as a means of self- , while boys are more likely to self-injure in the aftermath of a romantic break-up (Adler & Adler 2007; Rodham et al. 2004). But most research on NSSI overlooks these gender differences. Boys who are failing in every aspect of their life, who hit the wall during an argument, are lumped into the same category with girls who seem to be doing great, but who are cutting themselves in secret.

It's risky to look at celebrity culture for any insights into the human condition, but in this case I think the stories of celebrities illustrate reasonably well what I'm hearing from young people, female and male, around the United States and Canada. Megan Fox told Rolling Stone that she had deliberately cut herself as a teenager. Angelina Jolie, Lindsay Lohan, Amy Winehouse, and the late Lady Diana Spencer all have been identified as women who repeatedly and deliberately injured themselves. By contrast, the best-known case of a male celebrity who cuts himself is Marilyn Manson. I think Mr. Manson would agree that he takes pride in being a weirdo. And he likes to cut himself—on stage.

In other words, the girls who are most successful at meeting gender-specific societal expectations appear to be just as likely as other females to be cutting themselves. Not so for boys. How come? That's one of the questions I try to answer in my book Girls on the Edge. My bottom line is that these pretty girls are searching for a sense of self that's not about how they look, but about who they are. We reward them for how they look but we—i.e., American society—are much less interested in what's going on inside. Self-cutting fills that need for some of these girls, just as anorexia does for others, and obsessive does in others (see Sara Rimer's insightful article for the New York Times about "anorexia of the soul" among hyperachieving 'amazing' girls for more on this point).

Of course we need to be just as concerned about girls who do NOT meet society's stereotyped notions of what girls should look like, and who are cutting themselves. But I think that ignoring gender differences in NSSI disadvantages many of those who are struggling with this issue—especially girls (both 'pretty' and not).

I'm bothered that so few people want to address the gender differences in NSSI, which I think are absolutely central to understanding why these young people are hurting themselves, and essential to intervening effectively with them.

Gender matters. Why are people so afraid to talk about it?