Building wellbeing in young people with depression: Adapting Augmented Depression Therapy

<p dir="ltr">Depression in young people is highly prevalent and has severe repercussions throughout the lifespan. Psychological treatments are only moderately effective and improving outcomes is an urgent public health priority. Identifying novel treatment targets, such as the positive valence system (PVS), may improve outcomes. In young people with depression, PVS impairments are highly prevalent, central to diagnosis and phenomenology, and prognostically relevant. In adults, PVS outcomes such as anhedonia, positive affect and wellbeing, are poorer compared to negative affect, and depression. Augmented depression therapy (ADepT), a novel psychological treatment for depression, targets wellbeing alongside symptoms, has been validated in adults, and is yet to be explored in young people. Moreover, to adapt and refine ADepT for young people, an understanding of ADepT’s mechanisms is necessary. The overall aim of this thesis was to adapt ADepT to treat depression in young people. First, I conducted a systematic review (Chapter Two) to examine whether current treatments for depression in young people adequately target anhedonia, positive affect, and wellbeing. Next, I conducted a case series (Chapter Three) to assess the feasibility, acceptability, and preliminary effectiveness of ADepT for young adults with depression. Finally, I examined whether experiential processing (EP) is a mechanism underlying ADepT’s effects on the PVS. This included a questionnaire validation study (Chapter Four) in which I validated a novel scale measuring Basic Awareness of Sensory Experiences (BASES) in young adults. I also did an experimental study (Chapter Five) in which I used ecological momentary sampling to investigate the impact of an EP manipulation on positive affect during a pleasant outdoor walk. Collectively, my thesis presents several novel contributions, with a range of research and clinical implications, for the field of positive clinical psychology interventions for depression in young people.</p>