(NEW YORK) Reuters Health - As early as third grade, some children are hitting, cutting or otherwise hurting themselves, according to new research.

Studies have suggested about one-fifth of teens and young adults engage in self-injury at some point to relieve negative emotions or reach out for help, for example. But this report is the first to ask the question of kids as young as seven. Researchers found one in 12 of the third-, sixth- and ninth-graders they interviewed had self-injured at least once without the intention of killing themselves.

A lot of people tend to think that school-aged children, they're happy, they don't have a lot to worry about, said Benjamin Hankin, a psychologist from the University of Denver who worked on the study. Clearly a lot more kids are doing this than people have known.

Hankin and his colleagues spoke with 665 youth about their thoughts and behaviors related to self-harm. They found close to eight percent of third graders, four percent of sixth graders and 13 percent of ninth graders had hit, cut, burned or otherwise purposefully injured themselves at least once. In younger kids hitting was the most common form of self-injury, whereas high schoolers were most likely to cut or carve their skin.

Ten of the kids, or 1.5 percent, met proposed psychological criteria for a diagnosis of non-suicidal self-injury, meaning they had hurt themselves at least five times and had a lot of negative feelings tied to the behavior, the researchers reported Monday in Pediatrics. Youth who self-injure often say they do it to help stop bad emotions, or to feel something -- even pain -- when they are otherwise feeling numb, according to psychologists.

You can have young kids who are experiencing a lot of emotions, things that they don't know how to deal with it, so they start banging their head against the wall, Hankin said. Or, parents might ask kids to do chores, and to protest they self-injure. I think a lot of times parents think this is just attention-seeking behavior, said Steven Pastyrnak, head of pediatric psychology at Helen DeVos Children's Hospital in Grand Rapids, Michigan.

But, he added, most kids he sees self-injure because they are looking for ways to express their depression, anxiety or anger. Parents might not know kids are hurting themselves, especially older youth who if they do self-injure, often do so in private. But it's always a good idea to pay attention to changes in kids' behavior, as well as trouble eating or sleeping, and talk to their pediatrician if parents are worried, researchers said.

Stephen Lewis, who has studied self-injury at the University of Guelph in Ontario, said parents who do find out their child may be self-harming should consider the most helpful way to respond, even if they're upset.

What's important is to react in a way that conveys the parent cares about their child, and to act in a calming way and a non-judgmental way, Lewis, who wasn't involved in the new study, told Reuters Health.

For parents, the first step would be to talk to their child about it, to try to understand what's going on -- what's motivating it, and what might be going on in the child's life that's contributing to it.

That could be relationships with friends, for example, or trouble at school that kids don't know how to deal with, Lewis added.

Clearly the 1.5 percent who are meeting criteria, they're pretty serious, Hankin said. But even those who are doing it once or twice, hopefully they can get some kind of help, because the concern is that can lead to something further, such as suicidal feelings or generally poor health.

The bright side is, typically anxiety and depression as well as (self-injury) are very treatable, Pastyrnak, who also wasn't involved in the new study, told Reuters Health.

Psychologists might teach kids skills such as muscle relaxation, breathing and positive self-talk to help them cope with negative feelings, he added.

With the right help, these things don't have to be long-term problems for kids.

SOURCE: bit.ly/jsoh2P Pediatrics, online June 11, 2012.