Paper 1: What is the Effectiveness of Dialectical Behaviour Therapy in the Treatment of High-Risk Behaviours in Adolescents? A Systematic Review. Paper 2: The Relationship Between Early Life Stress, Amygdala Reactivity and Coping Behaviour Across the Life Span: An fMRI Study

Abstract

Paper 1: High-risk behaviours (HRB) are understood to serve a function of regulating emotions in the absence of other adaptive coping strategies. Engagement in multiple HRBs during adolescence is known to contribute to increased risk of suicide and psychopathology. Dialectical Behaviour Therapy for adolescents (DBT-A) has received attention for treating HRB in adolescents over recent years. Previous reviews have either provided a narrow focus on one HRB in isolation, and/or have focused broadly on several interventions’ effectiveness in treating HRBs. This systematic review aimed to synthesise the literature across six databases, exploring the effectiveness of DBT-A (including both individual and group DBT sessions) on a range of HRBs in various settings. Eleven papers met the search criteria and were included within the review. A narrative synthesis of the findings provided evidence for DBT-A reducing a range of HRBs in comparison to control conditions, with particular benefits for suicidal ideation and self-harm. Improvements in self-harm were more likely to be maintained over follow-up, whereas between-group differences in other HRBs were often lost over time. Studies varied considerably in quality, treatment length, frequency, and intensity. The implications for future research and practice are discussed. Paper 2: Objective: Following early life stress (ELS), individuals have been shown to develop maladaptive coping strategies including externalising behaviours such as aggression that persist across the life span. Yet, little is known about the possible underlying mechanisms for this association. This study explored these relationships using neuroimaging methods and clinical data from a 30-year longitudinal dataset investigating adults with ELS and cross-sectional controls without ELS. Methods: Forty-one participants (Mage = 25.66 years, SD = 2.96) participated in the study: 15 participants with ELS, and 26 controls. Participants completed the Amygdala Reactivity Paradigm while a functional magnetic resonance imaging (fMRI) scan was recorded to probe amygdala reactivity and behavioural responses to emotionally salient stimuli. Blood-oxygen-level-dependent signals from bilateral amygdala and relevant subfields were analysed and correlated with clinical measures of coping in adulthood, and aggressive/hostile behaviour across the lifespan. Results: Although fMRI data showed no significant between-group differences on contrasts of interest, key differences were noted on trials of neutral faces. Compared to controls, individuals with ELS demonstrated significantly faster reaction time on all trials with greatest difference for neutral faces, and significantly less accuracy on trials with negative faces and shapes, but not neutral faces. Higher amygdala reactivity to neutral faces was significantly positively correlated with emotion-oriented methods of coping in adulthood, and aggressive and hostile behaviours during mid-adolescence and adulthood but not childhood or late-adolescence.