Insecure attachment, emotion dysregulation and reflective functioning in adolescent substance use involvement; and, An initial meta-analysis of the effectiveness of third wave cognitive-behavioural therapies in the treatment of substance-use outcomes
Problematic substance use presents as a complex and costly challenge to society. Literature in the field of substance use is scarce, particularly within the developmental context of adolescence. Emerging research suggests that insecure attachment predicts substance use. However, the mechanisms underlying this relationship are poorly understood. Traditional treatment approaches for substance misuse predominantly focus on behavioural outcomes such as abstinence and relapse, however, high rates of relapse and patient drop-out have been observed across studies. There is a need for further research in establishing mechanisms underlying substance use and the development of substance use disorders to identify treatment targets and develop effective evidence-based psychological interventions. The first chapter of this portfolio presents findings from a cross-sectional empirical study investigating the role of insecure attachment (i.e., anxious and avoidant attachment), emotion dysregulation and reflective functioning in adolescent substance use involvement. The primary objective of the study was to test a proposed serial theoretical model: insecure attachment would predict greater emotion dysregulation, this would lead to lower levels of reflective functioning, and subsequently greater levels of substance use involvement. A secondary objective was to explore variations in effects across relationship domains (i.e., maternal-figure, paternal-figure, romantic relationship, and friendship). Emotion dysregulation and reflective functioning were found to mediate the effects of insecure attachment and substance use involvement for both anxious and avoidant attachment styles. This effect varied across relationship domains, with magnitude of effect strongest for friendship anxious attachment, closely followed by romantic anxious attachment. Weaker effects were observed for maternal anxious attachment and for both anxious and avoidant paternal attachment. Chapter one concluded that emotion dysregulation and reflective functioning may be important mechanisms in the relationship between insecure attachment and substance use outcomes, and that the strength of the influence of these variables vary across relationship domains during this developmental period. The second chapter of this portfolio reports findings from an initial meta-analysis reviewing the evidence of third wave psychological therapies in the treatment of substance use outcomes (i.e., severity, frequency, and cravings). Systematic searches of databases yielded 31 studies that met criteria for inclusion in the review, with 25 studies included for meta-analysis. Results highlighted that third wave interventions were effective in reducing substance use cravings relative to control groups. No significant effects were observed for frequency or severity outcomes relative to controls. Post-hoc analysis for the effectiveness of third wave interventions on negative affect was non-significant. Poor methodological quality and high risk of publication bias across studies limited the ability to draw firm conclusions. Methodological issues are highlighted and future recommendations considering such shortcomings are provided. Taken together, the findings from this portfolio contribute to the current evidence-base for potential transdiagnostic mechanisms involved in the development and maintenance of substance use, and the use of third wave interventions in treating substance use outcomes.