While deaths by suicide among preteens are rare, they are increasing, and self-injurious thoughts and behaviors are occurring with “concerning frequency,” according to a systematic review and meta-analysis.
Among over 600 million individuals across 58 studies, the lifetime prevalence of suicide was 0.79 per 1 million children across the general population, and pooled prevalence estimates for suicidal ideation, suicide attempts, and nonsuicidal self-injury were 15.1%, 2.6%, and 6.2%, respectively, among community samples, reported Richard Liu, PhD, of Massachusetts General Hospital and Harvard Medical School in Boston, and colleagues.
In addition, approximately 17% of preteens who have suicidal thoughts will later attempt suicide, they noted in JAMA Psychiatry.
“Roughly one in a million children will end up dying by suicide,” Liu told MedPage Today.
As of 2019, suicide was the fifth leading cause of death in pre-adolescents — up from the 10th leading cause in 2008, according to the CDC. The National Institute of Mental Health held meetings in 2019 and 2021 to address what Liu and his colleagues describe as a “worrying trend,” and called for scientists to prioritize research in this area.
Sadly, when younger children and preteens talk about hurting themselves, their comments are often discounted because of their age, Liu said. “They don’t mean that” or “They don’t really know what they’re saying,” are common reactions, he noted.
“And I think that these data show that … these statements are concerning, because they’re not as rare as we might think,” he added. “Fifteen percent of kids in that age group do have thoughts of suicide within their lifetime … that’s alarmingly high.”
While the study could not determine what causes suicidal ideation, the authors did identify “correlates of risk.” The strongest correlates for suicidal ideation included ADHD (d=0.54, 95% CI 0.34-0.75) and depression (d=0.90, 95% CI 0.71-1.09). In addition, child maltreatment yielded the largest effect size (d=2.62, 95% CI 1.56-3.67). By contrast, parental support (d=-0.34, 95% CI -0.46 to -0.22) was protective against suicidal ideation.
As for differences between the sexes, “what we know is that for attempts by suicide … adolescent and adult females are more likely to attempt. And what we’re seeing with preteens is that it’s either equal or skewed towards males.”
While almost no racial or ethnic differences were revealed in the study — with the exception of “a small negative association” suggesting that racial minorities were less likely to have suicidal thoughts — the lack of such findings may be due to the fact that the data don’t reflect “temporal trends,” such as the increasing suicide rates among Black children.
For this study, Liu and colleagues conducted a literature search of peer-reviewed journals in MEDLINE, PsycINFO, and Embase from inception through Dec. 23, 2021 for studies on the prevalence and correlates of preadolescent self-injurious thoughts and behaviors. Studies involving behaviors characterized as adverse events in clinical trials or “stereotypic self-harm” in children with developmental disorders were excluded.
What struck Liu most when conducting research was “just how little we know” about this age group, he said.
In decades of research, only six studies looked at the relationship between depression and suicide attempts in preteens — a well-worn line of study in other age groups.
Furthermore, except for biological sex, the authors also found a “notable absence of data” on correlates of suicide attempts and nonsuicidal self-injury. “Nonsuicidal self-injury predicts future suicide attempts, even more so than past history of suicide attempts,” Liu pointed out. “The fact that we know so little about nonsuicidal self-injury in preteens means that we’re really missing a lot of information on one of the biggest risk factors for suicide attempts in this age group.”
“The vast majority, if not all of these studies, are based on cross-sectional data … so what that means is we don’t know how they’re temporarily related. We can’t be certain that these correlations are things that predict suicidal ideation, suicide attempts, or deaths by suicides,” he noted.
For example, Liu said that while bullying might be viewed as a predictor of suicide, some teens are bullied because of their self-harm behaviors. “So, how do we know that bullying is what leads to their risk for suicidal ideation and not the other way around?”
Longitudinal studies could help tease apart whether certain correlates truly are predictive of suicide, he said. “What the study does is show us what is known … but it also tells us what we don’t yet know,” which can help guide future research.
If you or anyone you know is struggling with a mental health concern or having thoughts of suicide, please call the National Suicide Prevention Lifeline at 1-800-273-TALK (8255).
This study was supported in part by the National Institute of Mental Health and the National Science Foundation Graduate Research Fellowships.
Liu reported grants from the National Institute of Mental Health during the conduct of the study and personal fees from Relmada Therapeutics for consulting outside the submitted work. No other disclosures were reported.