Suicide rate among youth who self-harm 30 times higher than general population

Keith Hawton

Children and adolescents who self-harm have a significantly increased risk for future suicide compared with those in the general population, according to findings of a prospective observational cohort study conducted in England and published in The Lancet Child & Adolescent Health.

Researchers noted that this risk is especially prevalent among those who repeated self-harm, older adolescents and males.

“Although suicide following self-harm in children and adolescents is not common, young people who self-harm nonetheless have a considerably greater risk for suicide than other young people who do not self-harm,” Keith Hawton, FMedSci, of the Centre for Suicide Research at University of Oxford, told Healio Psychiatry. “Self-harm in these patient populations must be taken seriously. In all cases, there should be a careful assessment of the young person’s problems, risks and needs, which should lead to an individualized treatment plan to try to improve each individual’s situation and hence reduce risk.”

According to Hawton and colleagues, prior research has established a link between self-harm and excess subsequent mortality, with death by suicide particularly common in the first year following presentation for self-harm. However, there is a lack of published studies of deaths after self-harm among younger individuals, they noted.

To address this research gap, the researchers analyzed data of 9,173 individuals aged 10 to 18 years who were included in the Multicentre Study of Self-harm in England — an ongoing project that collects data on all self-harm presentations to the EDs of five general hospitals in England. Hawton and colleagues used mortality after presentation to hospital for self-harm as the key outcome, and they categorized these presentations as suicide, accidental deaths and death by other causes. Using Cox proportional hazard models, they estimated associations between three risk factors — sex, age and previous self-harm — and suicide.

The patients had 13,175 presentations for self-harm between January 2000 and December 2013. The rate of suicide among this patient population in the first year after presentation was more than 30 times higher than the expected rate in the general population of those aged the same and living in England (standardized mortality ratio = 31; 95% CI, 15.5-61.9). The increased risk remained at a similar level over the 10 years of follow-up, the researchers noted.

A total of 124 patients (1%) had died by the follow-up date of Dec. 31, 2015. Of these deaths, 44% were suicides, 22% were accidental and 34% were due to other causes. Thus, 0.6% of individuals who presented for self-harm died by suicide.

The researchers found that 82% of suicide deaths involved self-injury. Further, it was common for individuals to switch method between self-harm and suicide, especially from self-poisoning to asphyxiation or hanging.

Most (76%) of the 55 suicides occurred after age 18 years. Increased suicide risk was associated with several factors, including male sex (adjusted HR [aHR] = 2.5; 95% CI, 1.46-4.26), being an older adolescent at ED presentation for self-harm (aHR = 1.82; 95% CI, 0.93-3.54), use of self-injury for self-harm (aHR = 2.11; 95% CI, 1.17-3.81) and repeated self-harm (aHR = 1.87; 95% CI, 1.1-3.2). Males were significantly more likely to experience accidental poisoning deaths than females (OR = 6.81; 95% CI, 2.09-22.15).

“Prevention of self-harm should be a priority in national mental health planning for young people, with particular attention to educational and social strategies that might help reduce their problems and enhance resilience so that there is less likelihood of them self-harming,” Hawton said.

In a related editorial, Rohan Borschmann, PhD, of the Centre for Health Equity at Melbourne School of Population and Global Health in Australia, and colleagues wrote that the “considerable hazards” posed by self-harm in young people require coordinated action.

“Timely responses to mitigate this risk will require social scaffolding and support for young people and their families, their schools, their workplaces and their peers,” they wrote. “Such responses will require commensurate coordinated policy and practice efforts across the health, education and social care sectors. Given the well-documented social gradient in health, evidence-informed efforts to reduce adolescent self-harm will disproportionately benefit vulnerable subgroups of young people, thus directly addressing the Sustainable Development Goal of reducing inequalities.” – by Joe Gramigna

Disclosures: Hawton reports being a National Institute for Health Research senior investigator emeritus. Please see the study for all other authors’ relevant financial disclosures. The editorial authors report no relevant financial disclosures.