Most Adolescents Outgrow Self-Harm Behavior

But Those Who Don't May Be at Increased Risk for Poor Mental Health Outcomes, Including Suicide

Caroline Cassels

November 16, 2011

November 16, 2011 — One in 12 teens engage in self-harm behavior but the vast majority spontaneously stop as they enter adulthood, a large population-based study shows.

Nevertheless, investigators warn that as one of the strongest predictors of completed suicide, self-harm, along with other common mental disorders such as depression and anxiety, may be an important, yet largely unrecognized, component of suicide prevention.

Researchers at King's College London Institute of Psychiatry in the United Kingdom found that among individuals who self-harm as adolescents, 90% stop spontaneously, while the remaining 10% continue to self-harm into adulthood.

In addition, a small subgroup of study participants initiated self-harm in early adulthood. When investigators examined this subgroup they found these individuals were more like to have experienced depression and anxiety in their teenage years.

"Self harm was common but the majority gave it up. Notwithstanding this, teenage self-harmers often have serious emotional difficulties," principal investigator Paul Moran, MD, told reporters attending a press briefing.

The study is published online November 17 in The Lancet.

Natural History Tracked

Although the findings are somewhat reassuring, Dr. Moran added they highlight the importance of recognizing and addressing signs of persistent distress in youth to avoid escalation of mental health problems — including suicidal behavior — down the road.

Self-harm is one of the strongest predictors of completed suicide and is most prevalent among young women aged 15 to 20 years, in whom rates are rising.

However, researchers note that knowledge of its natural history is scarce, particularly during the transition from adolescence to young adulthood.

This longitudinal study, said Dr. Moran, marks the first time the natural history of self-harm has been tracked.

To describe its course from middle adolescence to young adulthood, the researchers followed a sample of young individuals from the state of Victoria, Australia, from 1992 to 2008 and collected self-harm data at 9 time points throughout the study. The mean age of participants at was 15 years at study entry and 29 years at final follow-up.

More Common in Girls

Among the total cohort of 1802 participants in the adolescent phase, 149 (8%) reported self-harming between the ages of 14 and 19. More girls (10%) than boys (6%) engaged in self-harm, translating into a 60% increase of self-harm in girls compared with boys (risk ratio, 1.6; 95% confidence interval [CI], 1.2 - 2.2).

Cutting and burning were the most common forms of self-harm, a finding that is concordant with data from other cross-sectional studies of young people, said Dr. Moran.

The study showed a substantial reduction in the frequency of self-harm during late adolescence. A total of 122 participants who reported self-harm during late adolescence reported no further self-harm in young adulthood. However, at each phase of follow-up, substantially more girls reported self-harming than boys.

"This appears to be primarily a teenage female phenomenon, although there were male self-harmers," said Dr. Moran.

Self-harm was also independently associated with symptoms of depression and anxiety (hazard ratio [HR], 3.7; 95% CI, 2.4 - 59), antisocial behavior (HR, 1.9; 95% CI, 1.1 - 3.4), high-risk alcohol use (HR, 2.1; 95% CI, 1.2 - 3.7), cannabis use (HR, 2.4; 95% CI, 1.4 - 4.4), and cigarette smoking (HR, 1.8; 95% CI, 1.0 - 3.1).

Window of Vulnerability

Co-investigator George C. Patton, MD, professor of adolescent health research, University of Melbourne, Australia, said that although the mechanisms underlying the phenomenon of self-harm in adolescence are not entirely clear, it appears to be a problem of emotional control that may have a biological basis.

Feeling overwhelmed by emotions that seem intolerable, adolescents may turn to self-harm as a way of dealing with these feelings, said Dr. Patton. The window of vulnerability for self-harm, he added, appears to open around puberty.

"If you take two 14-year-old girls one in late puberty and one in early puberty the risk of self-harm for the girl in late puberty is about 5-fold higher than for the girl in early puberty."

"Why that is we're uncertain but it may have something to do with the biological changes that occur around that time. There are tremendous changes in the hormonal environment and we know that these effect emotions particularly in young girls. There are also tremendous changes in some of the brain structures such as the amygdala which we know to be very important in generating emotions," he said.

Dr. Patton added that the risk of self-harm "diminishes very rapidly" as teenagers approach adulthood. Again, the exact mechanism is unclear, but it may be attributable to maturing of the prefrontal cortex, which is "crucially involved in emotional regulation and in planning and problem solving."

Fast-track to Adulthood

However, he added, it is clear that the basis for self-harm is not all biologically driven and that environment and social context "make a huge difference."

"We know from this and other studies that it is those young people who are on the fast track to adulthood — those kids who are on the margins of their families, the margins of school who are engaged in early sexual activity, who are using alcohol and other drugs at an early age — this group of kids is at the highest risk of self-harm," said Dr. Patton.

"We are talking about a window of vulnerability which lasts through the mid-teens where we believe social scaffolding for young people is very important. Young people are going to be most protected from self-harm by good connections and good involvement with their families, with school engagement, with commitment to school and their local neighbourhood and good relationships with their peers," he added.

In an accompanying editorial, Professor Keith Hawton, director of the Centre for Suicide Research, University of Oxford, United Kingdom, and Professor Rory C. O'Connor, University of Stirling, United Kingdom, note the study offers "some reassurance to parents of adolescents who self-harm and to health and educational agencies."

"Clinicians can offer encouragement to both young people who are self-harming and their families. Their findings raise important questions relevant to the prevention of persistent self-harm and the onset of self-harm and suicidal behaviour in early adulthood," they write.

Tip of the Iceberg?

In the press conference, Dr. Hawton said statistics on the prevalence of self-harm may only represent the "tip of the iceberg."

Many of the previous estimates of self-harm, he said, are based on data from centers where adolescents present for treatment, including hospital emergency departments and other clinical services.

"We estimate that 1 in 8 come to clinical attention or go to hospital. These are the overt cases, but below these and hidden away to a large degree you have self harm at the community level."

The current study, he added, likely provides a more accurate estimate, although it is possible that it still may be an underestimate.

Among individuals of all ages who die by suicide, 50% to 60% have a history of self-harm, and of these, 25% presented to hospital with self-harm in the previous year, said Professor Hawton.

Niall Boyce, MD, a psychiatrist and senior editor at The Lancet, said the current study's longitudinal design provides insight into the cause of self-harm. Further, he noted, it provides important information about prognosis.

"I thought [the paper] was a tremendous contribution to the literature and I was very pleased and honored to be able to take it through to publication," said Dr. Boyce.

The authors and editorialists have disclosed no relevant financial relationships.

Lancet. Published online November 17, 2011. Study abstract Editorial extract


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