Self-harm in adolescents and young adults represents an important public health issue . Community surveys indicate that around 5 to 10% of adolescents report self-harm over the last year [2–5]. International comparisons for 15 to16 year olds have indicated that rates of self-harm in the UK are amongst the highest in developed countries, with 3.2% of males and 11.1% of females reporting self-harm over the last year and with lifetime prevalence rates of 4.8% for males and 16.7% for females . Despite its high prevalence, self-harm in adolescents often goes unreported and undetected . As previous self-harm increases the risk of doing so again and repeated self-harm is a risk factor for suicide [6–9], proactive identification of young people who are at risk is important.
Self-harm is referred to in several ways in the literature, including ‘self-mutilation’, ‘non-suicidal self-injury’ (NSSI), ‘self-injurious behavior’, ‘parasuicide’, ‘self-wounding’, or ‘self-poisoning’ . The most common methods of self-harm reported in community settings are self-cutting (or self-laceration) and self-battery (e.g. head-butting a wall or pulling hair) [10–12]. Self-poisoning (or overdose) is less common in the community, but is strongly associated with the presence of suicidal intent  and is the most common method in those presenting to hospital following self-harm . Self-poisoning is more common in girls than in boys, who more frequently report self-battery as a method of self-harm [11, 12]. Motivations commonly reported for self-harm include: coping with negative emotions; self-loathing; anger; self-punishment; loneliness; distraction from problems, and; to communicate bad feelings to others [11, 12]. Girls are more likely to report reducing negative emotions as a motivator, while boys have a greater tendency to report more superficial reasons like boredom or curiosity [11, 12]. Almost half of young people report feeling better after self-harming and this is most common in those who self-harm frequently . However, feelings of guilt, shame, and disgust can also increase following self-harm .
While there are key differences between self-harm with and without suicidal intent in terms of different methods of self-harm, motivations, reinforcers, neurobiology, and association with suicide, they also share some common risk factors and can occur in the same individuals [7
]. Approximately 25% of adolescents who have self-harmed report having suicidal intent during their last episode [11
]. Kidger et al. [11
] state that:
“Although the majority of self-harm behaviour is not accompanied by a desire to die, all self harm regardless of motivation is associated with increased risk of suicidal thoughts and plans, particularly when it is carried out repeatedly” (p. 1).
Therefore, while there are various definitions of self-harm, this manuscript adopts a broad definition to encompass deliberate self-injury or self-poisoning, in line with British guidelines , and includes self-harm with or without suicidal intent.
A wide variety of assessments have been developed that directly inquire about self-harm and suicidal ideation in adolescents, including the Columbia Suicide Screen, Suicide Risk Screen, and the Risk-Taking and Self-Harm Inventory for Adolescents [17–19]. However, self-harm and suicide are sensitive and stigmatised issues. Non-mental health specialists are not typically accurate in identifying mental health problems (particularly internalizing disorders) and can find it difficult to distinguish between normal variation in mood and precursors to more serious mental health problems [20–23]. People who are not mental health professionals, such as teachers and youth justice workers, find it difficult to ask adolescents about suicide and self-harm and disclosure can be met with feelings of intense anxiety [24–26]. There is also a pervasive concern that asking about suicidal thoughts or behaviour could trigger suicidal ideation or attempts, despite evidence that enquiring about suicide is not harmful .
The reluctance of non-psychiatric professionals to directly ask about self-harm has led some to investigate whether training community-based professionals can increase awareness and improve identification. However, training school-based staff has variable results and seems to particularly benefit those who are already able to talk with students about suicide and distress . Whilst helping non-psychiatric professionals to talk about self-harm would be the ideal solution, practically they find this very difficult and alternative more indirect approaches need to be investigated.
A number of risk factors for self-harm have been identified including depressed mood, increased anxiety, low self-esteem and cognitions that focus upon self-failure [1, 29–32]. Depression and anxiety in adolescence are associated with an increased incidence of self-harm in young adulthood . Self-report measures can assess these variables in adolescents in community settings in a valid and reliable way [33–36]. An indirect approach such as this would be more acceptable and offers the potential to identify those who are self-harming or at increased risk of future self-harm. However, general measures of depression and anxiety may lack discriminative ability in distinguishing between those who do and do not self-harm . The aims of this study are to investigate whether a brief set of items can be identified from existing measures of negative emotion and self-esteem that are sufficiently sensitive and specific to identify adolescents at risk of self-harm in community settings.