Thursday November 17 2011
Self-harm in adolescence was significantly linked to symptoms of depression and anxiety
“One in 12 people self-harm in their teenage years,” the BBC has reported. For most people the problem will resolve before adulthood, but for 10% it will continue into their adult lives, it continued.
This alarming statistic, estimated in an Australian study, corroborates existing estimates that around 8% of UK teens deliberately harm themselves.
This well-conducted new research surveyed almost 2,000 Australian adolescents over a period of several years, assessing them from around 14-15 years of age until they were into their late 20s. It found that between the ages of 14 and 19, 8% of the sample, mainly girls, reported they had self-harmed. Self-harm in adolescence was significantly associated with symptoms of depression and anxiety, antisocial behaviour, high-risk alcohol use, and smoking cannabis and tobacco.
A substantial drop in reported self-harm occurred as adolescents grew into young adults, though adolescent depression and anxiety were linked to self-harm in young adulthood.
There are some inherent problems that come with researching areas such as self-harm, particularly in making sure that the information provided by participants is accurate and that the numbers who self-harm are not underestimated. Also, it should also be noted that though the researchers found associations between self-harm and various psychosocial factors in adolescence, the study’s design cannot demonstrate the specific causes why.
Though this carefully conducted study suggests that although most adolescent self-harm may resolve spontaneously, this does not undermine the importance of the issue, and that it can be a sign of greater mental health problems that may eventually lead to continuing self-harm or even suicide. Self-harm can take many forms and may be associated with various emotional, personal or lifestyle circumstances.
Any individual that self-harms requires immediate and supportive care and attention, and should seek medical help or advice immediately.
Where did the story come from?
The study was carried out by researchers from King’s College London, and the Murdoch Children’s Research Institute, the University of Melbourne and Deakin University in Australia. It was funded by the National Health and Medical Research Council of Australia and by the Government of Victoria.
The study was published in the peer-reviewed medical journal The Lancet. It was reported at length by BBC News and The Guardian, with both including comments from external experts.
What kind of research was this?
This was a cohort study that looked at patterns of self-harm from middle adolescence to early adulthood, in a sample of 1,943 adolescents. This type of study, which enables researchers to follow up large populations over lengthy periods, is often used to examine health outcomes and how they relate to lifestyle factors. However, when factors are assessed at the same time (e.g. self-harm and other lifestyle factors in adolescence) it can only demonstrate associations, and cannot show that any one factor directly caused a particular outcome.
The researchers define self-harm as an act with a non-fatal outcome in which an individual deliberately initiates behaviour (such as self-cutting) with the intention of harming themselves. They point out that self-harm is one of the strongest predictors of suicide and is particularly common in 15- to 24-year-old women, among whom rates are thought to be rising. However, little is known about the natural history of self-harm, especially during the transition from adolescence to early adulthood. Charting the course of self-harm during this period might help provide insight into the risk factors for future suicide, they say.
What did the research involve?
Between 1992 and 1993, the researchers recruited a random sample of 2,032 schoolchildren aged 14-15 from 45 schools in Victoria, Australia. The schools were chosen at random and included government-run, Catholic and independent schools, with numbers reflecting the proportion of children this age in different types of schools.
Participants were asked to fill in questionnaires and give interviews by telephone both at the start of the study and in various “waves” of follow-up, generally conducted when the participants were aged between 16 and 29. Waves one and two were formed of two different classes with separate entry points to the study. Waves three to six took place at six-monthly intervals, from 14 to 19 years, with three follow-up waves in young adulthood, aged 20-21 years, 24-25 years and 28-29 years. Based on the time and way that these various waves were assessed, the researchers grouped responses into several waves for their analysis.
In waves one to six, participants answered questionnaires on laptop computers, with telephone follow-up of those absent from school. In young adulthood, only computer-assisted telephone interviews were used.
Out of the 2,032 students initially recruited, 1,943 participated at least once during the first six waves. One school dropped out after wave one.
The adolescent participants were asked about self-harm from wave three to nine. They were asked whether they had deliberately hurt themselves or done anything they knew might have harmed or even killed them during a recent period (one year during wave three, and six months for the other waves). Those who said they had self-harmed were then asked for more detailed information, including on suicide attempts.
The researchers also asked the adolescents in waves three to six about their use of cannabis, tobacco, high-risk alcohol intake (calculated according to national guidelines), symptoms of depression and anxiety, antisocial behaviour and parental separation or divorce. Where relevant, their responses were assessed and categorised using standardised interview questions and symptom scales.
The researchers used standard statistical methods to identify patterns of self-harm and any association between self-harm and other factors.
What were the basic results?
Overall, 1,802 (88.7%) of the participants responded in the adolescent phase. The main findings were as follows:
- 8% of adolescents (149 individuals, 10% of girls and 6% of boys) reported that they had self-harmed
- More girls (95 out of 947, 10%) than boys (54 out of 855, 6%) reported self-harm (risk ratio 1.6, 95% confidence interval (CI) 1.2 to 2.2)
- The self-harm reported was most often burning or cutting behaviour
- Less than 1% of adolescents reported having suicidal intentions
- There was a reduction in the frequency of self-harm during late adolescence, with the decline continuing into young adulthood
- In the young adult phase, the proportion of all participants reporting self-harm fell to 2.6% (46 of 1,750 interviewed between ages 20 and 29)
- Of those who had completed assessments both in adolescence and young adulthood (1,652), 7% (122) had self-harmed in adolescence but now no longer did so in adulthood, and only 0.8% (14) had self-harmed both in adolescence and adulthood. Some 1.6% (27) had started self-harming for the first time in adulthood
- During adolescence, self-harm was independently associated with symptoms of depression and anxiety (hazard ratio 3.7, 95% CI 2.4 to 5.9), antisocial behaviour (1.9, 1.1 to 3.4), high-risk alcohol use (2.1, 1.2 to 3.7), cannabis use (2.4, 1.4 to 4.4), and cigarette smoking (1.8, 1.0 to 3.1). Direct causation between these factors cannot be demonstrated
- Adolescent symptoms of depression and anxiety were significantly associated with self-harm in young adulthood (5.9, 2.2 to 16).
How did the researchers interpret the results?
The researchers conclude that most self-harming behaviour in adolescence ‘resolves spontaneously’, i.e. tails off without any formal intervention. However, they point out, young people who self-harm often have mental health problems that may go untreated. Treating anxiety and depression in adolescence could be an important strategy in preventing suicide in young adults, they add.
This carefully conducted study focuses on the important issue of self-harm during adolescence and its association with mental health problems such as depression and anxiety. Even if, as this study suggests, most adolescent self-harm may naturally resolve itself, untreated mental health problems may contribute to an increased risk of continuing self-harm or even suicide.
It should be noted that the study was conducted in Australia, where patterns of self-harm may be different from those in the UK. That said, the figure agrees with the estimates from UK organisations such as the National Institute for Health and Clinical Excellence, which calculates that around one in 12 15-16 year olds self-harms. The Mental Health Foundation places the figure at between one in 12 and one in 15 young people.
Also, the study relied on participants to reliably and truthfully report episodes of self-harm. Relying on participants to self-report these behaviours introduces the possibility of error, and these findings could even be an underestimate of the true prevalence; this could particularly apply to the results when young adults had their assessment interviewed by telephone, which might make it harder to openly discuss any self-harm. Checking against hospital records could possibly give a more accurate estimate, although as the authors rightly point out, most individuals who self-harm do not present to medical care.
Although the study had high response rates, the estimates generated from the overall responses could also be subject to further inaccuracy as only 51% of participants completed every “wave” of assessments.
It should also be noted that though the researchers found associations between self-harm and various psychosocial factors in adolescence, direct causation cannot be demonstrated between self-harm and any one factor due to the cross-sectional nature of this assessment. In short, while we have found that self-harmers were more likely to act or feel certain ways, such as being depressed, the design of this study means we cannot assume that we have identified a particular factor or cause behind the association.
Self-harm can take many forms and may be associated with various emotional, personal or lifestyle circumstances. Any such individual requires immediate and supportive care and attention, and should seek medical help or advice immediately.