De kracht van hechting: de rol van hechtingsrelaties bij zelfverwondingsgedachten en -gedragingen in adolescenten

Self-harm is amongst the leading causes of death and injury worldwide (Nock et al., 2008; WHO, 2008). The term self-harm is used to refer to any act of self-poisoning or self-injury carried out by an individual irrespective of motivation (NICE, 2011). The highest rates of self-harm thoughts and behaviour have been found in adolescents (Nixon & Heath, 2009), where around 17.2% have reported engaging in self-harm behaviour (Gandhi et al., 2019). Previous research has shown that engaging in self-harm increases suicide risk by ten times (Hawton, Saunders, & O'Connor, 2012). Even more adolescents have thoughts of self-harm without engaging in self-harm behaviour. Determining which of the adolescents who think (ideate) about self-harm will go on to translate those thoughts into behaviours (enactment) is key for preventing self-harm (Kirtley, O'Conner, & O'Carroll, 2015). Despite recent advances, some of the fundamental aspects of self-harm remain poorly understood; therefore, there is a need for a better understanding of the psychological processes underlying self-harm. The Integrated Motivational-Volitional Model (IMV) is a theoretical framework of suicidal behaviour, which conceptualizes suicide as a process, where individuals move from thoughts to behaviours. The IMV-model has three phases: the pre-motivational phase (background factors and triggering events), the motivational phase (ideation and intention formation) and the volitional phase (behavioural enaction). This diathesis-stress model aims to understand how suicidal ideation emerges and which factors increase the likelihood that ideation is translated into a suicide attempt. There is increasing evidence for the paths and processes outlined in the IMV model (Zortea et al., 2019). Investigating vulnerability factors in self-harm from the viewpoint of the IMV model can provide us with the opportunity to better understand and prevent the emergence of self-harm thoughts and behaviours. Studies show an association between attachment and self-harm, but the nature of the relationship and the underlying processes remain unclear. Furthermore, only limited research has examined adolescent self-harm within the context of attachment relationships (Ghandi et al., 2019; Bostik & Everall, 2006; Zortea et al. 2019). Investigating this relationship in adolescents is of great importance because adolescence is a key period of change in attachment. Adolescents are expected to detach from their parents, while social relationships with peers become more important. According to Bowlby's attachment theory, affective relational experiences of seeking and receiving caregiving from important attachment figures are internalized and generalized to all social interactions (Bretherton, 1992). Using the IMV-model as a comprehensive framework provides us with an opportunity to investigate the psychological processes that underpin the relationship between attachment and self-harm thoughts and behaviours. The IMV-model proposes feelings of defeat and entrapment as potential mediators in the relationship between attachment and self-harm. Rumination, social support, thwarted belongingness and perceived burdensomeness are proposed as potential moderators in the same relationship (O'Connor & Kirtley, 2018). To date, however, these processes have never been investigated in daily life, meaning that we know little about the dynamic and context-dependent nature of the relationships between these factors. When assessing relevant influences of attachment on daily life functioning and self-harm, cross-sectional and longitudinal studies fall short. Methods are hindered by recall and memory biases that do not allow for the assessment of fluctuation in affective and cognitive states. To more accurately assess the relevant psychological factors, these should be captured in context, i.e. in everyday life where these behaviours naturally occur (Humber, Emsley, Pratt, & Tarrier, 2013). Methods measuring self-harm thoughts and behaviours in daily life are lacking and prior studies have relied on long-term, retrospective, aggregate and self-report assessment methods (Nock et al., 2009). The experience sampling method (ESM) can offer a powerful and necessary solution by providing us with information about self-harm within, and in interaction with, the real-world context (Myin‐Germeys et al., 2018). This way possible distortion by memory is reduced and reliability is increased (Nock et al., 2009). ESM is the primary methodological approach of the Center for Contextual Psychiatry (CCP) where this PhD is being carried out. Using ESM allows us to investigate how attachment manifests in daily life behaviour as well as the relationship between attachment and actual self-harm thoughts and behaviours in adolescents, in the context of their everyday lives. This knowledge will improve our understanding of the role of attachment relationships in the process of experiencing self-harm thoughts and behaviours and could provide new targets for intervention and treatment development. In sum, daily life research on self-harm within the context of different attachment relationships is currently sparse, especially in adolescents, who are a high-vulnerability group for self-harm and undergo major attachment changes during this life period. In this PhD, I will use the IMV model (O'Connor & Kirtley, 2018) as a framework to investigate the role of attachment in self-harm thoughts and behaviours among adolescents from the SIGMA study, in combination with innovative ESM techniques. Better understanding of the dynamic processes involved in self-harm can aid prediction, early intervention and prevention efforts.