Risk factors for self-harm
Self-harm is more common in females, whereas completed suicide is more common in males (1). Seventy nine percent of all suicides occur in low- and middle-income countries (4). There are many identified risk factors for self-harm and suicidal behaviours as follows:
- Low socio-economic status
- Parental death
- Parental mental health problems
- Adverse childhood experiences
- History of physical and sexual abuse
- Low school connectedness
- Family discord
- Interpersonal difficulties
- Living apart from family or in foster care
- Family and friends who self-harm
- Internet/Social media use
- Lesbian, Gay, Bisexual, Transgender (LGBT) youth are at greater risk of self-harm
- Mental disorder
- Substance misuse
- Low self-esteem
- Personality traits (e.g. perfectionism, impulsivity)
- Sleep disturbance
(1, 6, 7, 10-15)
Risk factors for completed suicide
Research on completed suicide is challenging due to the, fortunately, low prevalence. In high-income countries, girls more commonly make suicide attempts, but boys are more likely to die by suicide (16, 17). This could be related to a number of factors, including the lethality of methods, as it is known that violent methods are much stronger predictors of suicide than non-violent methods (18). In the UK violent methods, such as hanging, tend to be greater in males (15). But in lower socio-economic index regions there is a higher female-to-male ratio of completed suicide (19). This may be due to higher levels of suicidal behaviour, or access to lethal means such as pesticides; which accounts for an estimated 30% of suicides worldwide (20). There are also some special groups. For example, young adult women who self-harm by cutting and are hospitalised, are at particular risk of future suicide (18). Other factors such as family history of suicide, poor educational attainment and familial separations (i.e. by divorce or death) are risk factors for suicide, as well as a history of self-harm (1)
Aetiology and why people self-harm
Self-harm occurs less frequently in children under 12, and becomes increasingly common during adolescence (1, 21). However, the majority of these young people do not continue to self-harm into adulthood (22). Self-harm behaviours may be associated with a particular life event, stressor, or episode of mental disorder, or may be more pervasive and become a regular and repeated occurrence.
Self-harm does not occur exclusively in the context of mental disorder and as outlined above there are many known psychosocial risk factors. It is however associated with a range of mental disorders including anxiety, depression and attention deficit hyperactivity disorder (ADHD) (1, 22). Substance use, sleep disturbances and personality traits of intellect/openness are also important predictors (15), along with young people having family and friends who self-harm (23). NSSI and suicidal behaviours are key features of Borderline Personality Disorder, but its diagnosis in adolescents has been deemed controversial in the past due to concerns about its validity and the potential for it being stigmatising (24). It is increasingly recognised that the disorder can be diagnosed in adolescence and there may be differing developmental trajectories, providing an opportunity for early intervention and treatment (25, 26).
There are unfortunately some stigmatising and unhelpful views which persist about self-harm, such that those that self-harm are ‘manipulative’ or ‘attention-seeking’. Why people initially self-harm may stem from a wide variety of situations and exposures, which are often complex. This can include communicating distress to others, a form of coping-mechanism, or to regulate emotions. Repeated self-harm is one of the strongest known risk factors for suicide (27) and roughly a third who die by suicide use the same method for their last self-harm and for suicide (28). Self-harm is not something that should be disregarded by professionals or carers and should be viewed as a sign of underlying distress or dysfunction which requires further assessment, as it may well be that a young person has no other means to communicate these difficulties.
Methods of self-harm and suicide
There is variability in methods of self-harm according to the availability of means and exposures and the method of self-harm does not necessarily predict the method of suicide. In high-income countries, self-cutting and self-poisoning with medication are amongst the most common methods of self-harm (1). However, methods such as charcoal burning (29) or ingestion of pesticides (30) are more widespread in other countries, particularly China.
Drug-poisoning is commonly used in suicide attempters, however completed suicides most often result from other more lethal methods such as pesticide/chemical poisoning, hanging or firearms (31-33).
Assessment and management of self-harm and suicide risk
Despite the high prevalence of self-harm, the majority of young people who self-harm are not known to professionals, with as few as 12% of self-harm episodes in young people presenting to hospital (34). This presents a major problem for societies and limits the number of young people reached by interventions.
The World Health Organization recommends that both specialist and non-specialist health providers seeing children over 10 years old with either a diagnosed mental disorder, interpersonal conflict, loss, or a severe life event, should be asked about thoughts and plans to self-harm (35). If the current presentation is with self-harm it is important to assess thoroughly past self-harm, the risk of further self-harm and suicide risk, alongside thorough psychosocial assessment. Young people use a number of methods to self-harm and may at different times have suicidal intent, or not. It is therefore important to ask about intent. Evidence suggests that, contrary to people’s apprehensions, talking about suicidality may in fact reduce thoughts about suicide and may lead people to seek help (36). This should therefore be an important area of enquiry in young people and mental health professionals should routinely screen for suicidal ideation and current or past self-harm.
It is a minority of young people who self-harm, who present to hospital (37), which makes prevention challenging on an individual level. Population-level interventions that restrict access to means are required and there is increasing interest in the role of school-based interventions for mental health (see ‘areas of uncertainty’).
Another widely used prevention strategy is safety planning. There is limited evidence in children, but in adults, safety planning interventions have been found to reduce suicidal behaviours and improve engagement (38). In acute presentations, safety planning, in collaboration with the young person and relevant carers, should include: clear follow up plans, useful contacts, strategies on how to communicate distress and coping skills. This should be reviewed and discussed regularly in future contacts. Restricting access to means is also an important aspect of safety planning and prevention, particularly of impulsive suicide attempts, hopefully providing some time to both reflect and for the crisis to pass.
Public health interventions to restrict access to means have been successful in some regions and include placing barriers at common jumping sites, detoxifying domestic gas and the banning of certain pesticides, or restricting their purchase (39). Legislative measures, safer firearm storage and improved firearm safety are all methods by which firearm-related suicides can be reduced (40); particularly relevant to the United States, where firearms are the most common method of suicide (41).
Media guidance on reporting of suicide is another important intervention. This guidance explains the importance of not sensationalising or over-simplifying the reasons for suicide or providing details on methods of suicide or self-harm. It also suggests that within the report, information about sources of support is provided (42).
Social environment, i.e. family, peers, school and neighbourhood connectedness, can be protective factors against self-harm. Connectedness with others is protective, though it appears that peer-connectedness is not as important when compared to relationships with supportive adults, highlighting the importance of family and school involvement. (43)
When self-harm occurs in the context of a mental disorder, the disorder itself should be treated, alongside management of the self-harm.
In terms of the management of self-harm, there are no evidence-based pharmacological interventions, however psychological interventions show promise, in particular Dialectical Behavioural Therapy (DBT), Mentalisation Based Therapy (MBT), and Cognitive Behavioural Therapy (CBT) (44). While these interventions show evidence of effect in reducing self-harm, their impact on reducing suicide attempts specifically is limited, and no one therapy can be recommended as superior.
It is well acknowledged that families are hugely important in the managing of risk and treatment of self-harm, and interventions with a family component are associated with a reduction in self-harm (44). As a result, most CBT, DBT, and related manuals, have incorporated family components. The Safe Alternatives for Teens and Youths (SAFETY), a “cognitive-behavioural DBT-informed family treatment”, has been shown to be effective in preventing suicide attempts (45). Systemic Family Therapy was not found to reduce hospital attendance for self-harm (46). Social support interventions such as the Youth-Nominated Support Team Intervention-Version II, which incorporates psychoeducation and the adolescent’s nomination of a ‘caring adult’, has shown promising results in reducing mortality in suicidal adolescents’ post-hospitalisation, but its wider usefulness requires further study (47, 48).
Hospital admission for any child or adolescent is uncommon, but there are occasions when risk of self-harm and suicide cannot be managed safely outside this setting and therefore hospital admission may be considered, with or without use of statutory frameworks for compulsory detention. However, hospitalisation of adolescents with repeated self-harm, can have adverse effects and therefore all efforts should be made to provide treatment in an outpatient setting where possible. In some areas, intensive treatment alternatives to hospital admission may be available, and this has been shown to be an effective way of managing young people (49). This is particularly important due to the fact that the period immediately after discharge from hospital is a time when young people are at high risk of suicide (50).