Using implementation intentions to reduce self-harm

Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2024
Thesis identifier
  • T16855
Person Identifier (Local)
  • 201853404
Qualification Level
Qualification Name
Department, School or Faculty
  • Implementation intentions (IMPs) are IF-THEN plans that require people to specify critical situations (e.g., situations that tempt a behaviour, such as self-harm) and link those situations with goal-directed responses (e.g., coping strategies). This research tested the effectiveness of an intervention technique (a volitional help sheet) designed to encourage the formation of IMPs to avoid self-harm thoughts and behaviour in the wider community. Chapter 1 discusses the prevalence and detrimental impact of self-harm behaviour and thoughts, and existing interventions. Chapter 2 introduces the concept of IMPs and reviews evidence suggesting that IMP interventions are likely to reduce self-harm. Potential motivational, volitional, and cognitive moderators of IMPs are also considered. Following a consideration of key methodological issues relating to the design of the present research (chapter 3), study 1 is presented in chapter 4. Study 1 showed that an IMP intervention reduced self-harm behaviour in the critical situations specified in participants’ plans. In line with expectations, this effect was observed only when individuals were motivated to reduce self-harm and experienced high levels of self-harm and suicide-related mental imagery. No effects were observed on other measured outcomes: self-harm in unspecified critical situations, suicidality, anxiety, and depression. Exposure to self-harm by friends and family did not moderate the effects of the intervention on any outcome measure. Study 2 (chapter 5) showed that the IMP intervention reduced self-harm thoughts in the participants’ specified critical situations. Consistent with study 1, this effect was observed only when individuals were motivated to stop thinking about self-harm. No effects of the intervention were largely observed on other outcome measures. Cognitive abilities (attention, and prospective and retrospective memory) did not moderate the effects of the intervention on self-harm thoughts, suicidality, anxiety or depression. However, there was evidence that they moderated the effects of the intervention on self-harm behaviour. Chapter 6 presents a pilot study for a clinical trial to test the effects of IMPs, and the moderators investigated in this thesis, on patients admitted to hospital for self-harm. A reflection on the pilot’s methods and results is presented with a view to a future, full-scale clinical trial. The overall findings across the three studies are discussed in chapter 7. Implications for practice and future research are presented.
Advisor / supervisor
  • Rasmussen, Susan
  • Nicholls, Louise Brown
  • Elliott, Mark
Resource Type
Date Created
  • 2023