Randomised Controlled Trial of a Smartphone-based App to Reduce Self-harm for CAMHS-treated Adolescents

Background Self-harm among young people is frequent (McManus et al., 2019) and presents a growing public health concern in England. To date, no robust and comprehensive evidence base exists for effective interventions to prevent self-harm in adolescents (Witt et al., 2021). Therapeutic interventions that are effective among adults, including dialectical behavioural therapy, are only offered to CAMHS patients being diagnosed with a severe mental illness. Young patients with experiences of self-harm and their carers need to access interventions quickly to improve clinical care and reduce future harm. Therefore, novel interventions need to be developed, tested, and evaluated for this vulnerable population.

One such potential intervention is the "volitional help sheet" (VHS). The VHS is a brief psychosocial intervention that significantly reduces thoughts and acts of self-harm in adults admitted to hospital following an initial episode of self-harm (O'Connor et al., 2017). It is based on IF-THEN statements that help people link critical situations to alternative appropriate responses (Armitage, 2008; Gollwitzer, 1993). An example is: "If I feel the urge to self-harm when I want to get relief from a terrible state of mind, then I will do something else instead of self-harming". IF-THEN statements are intended to act as automatic coping responses, especially in cases where people may feel the urge to self-harm.

The VHS has previously been successful in reducing self-harm in people recently admitted to hospital for self-harm (Armitage et al., 2016; O'Connor et al., 2017). Recent data have also demonstrated that a web-based version of the VHS was acceptable among a large representative sample of UK adults with self-harm experiences (Keyworth et al., 2021). However, it is yet to be known whether this intervention is effective and acceptable among adolescents. It is important to conduct this research with experts by experience to create an acceptable and effective intervention, particularly since talking about self-harm does not increase risk of self-harm (Biddle et al., 2013; Blades et al., 2018), and can actually be positive experience for patients (Alexander et al., 2018; Dazzi et al., 2014). This research will co-adapt and pilot the VHS intervention in adolescents presented at CAMHS following an initial episode of self-harm. To maximise engagement with the intervention, we plan to develop this as a smartphone app.

Methods Design Pilot randomised controlled trial. Participants Adolescents who have previously harmed themselves. Setting Data collection will take place online. We will recruit both adolescents that are currently under the care of CAMHS, and those who have been discharged back to community care.

Recruitment and sampling A sample of 90 adolescents that have experienced and index episode of self-harm will be recruited through purposive sampling via Salford CAMHS and 42nd Street.