In Search of bio-psycho-social markers for the recurrence of adolescent depression

Children and Young People's PhD Scholarship 2018 (2): Section of Clinical Psychology, School of Health in Social Science, University of Edinburgh.

Supervisor: Dr Stella Chan


Half of depression cases emerge in youth. Adolescent depression is notoriously difficult to treat and highly recurrent. Once an individual has had one episode of illness, the chance of developing a second episode is 60%; after two and three episodes, the chances rise up to 70% and 90% respectively. We urgently need to develop more effective treatments on the early stage of illness, before it develops into a recurrent pattern. This PhD will therefore focus on young people who have recovered from depression. The key hypothesis is that the experience of depression may result in biological and psychosocial changes (‘scar effects’) that make the individual more at risk for developing future episodes of illness. This PhD will examine these features, focusing on three areas:

i. Emotional processing – the way we attend to, interpret, and remember emotional information;

ii. Reactivity to stress – both in terms of biological functions indicated by cortisol levels (the ‘stress hormone’), quality of sleep, and psychological strategies of emotional regulation;

iii. Psychological scar effects – the way individuals cope with the sense of shame and stigma that are often associated with mental health difficulties.

This project consists of three studies using both quantitative and qualitative methods with longitudinal follow-up assessments to examine short- and long-term outcomes. Qualitative interviews will help capturing the lived experience of adolescent depression and identify factors that are subjectively important. The ultimate goal is to inform the development of better treatment and preventative strategies that can transform the quality of life across the life span.

Start Date: September 2018

Scientific Goal:

Half of depression cases emerge by the age of 25 [1]. Adolescent depression is typically a more severe form of the disorder and is notoriously difficult to treat [2, 3]. Notably, risk for recurrence increases with each episode of illness. Following one episode, 60% suffer another episode; after two and three episodes, the probabilities rise to 70% and 90% respectively [4, 5]. Hence, the experience of depression may itself have a causative influence on further clinical outcome. The overarching hypothesis is that ‘scar effects’ from previous depressive episode(s) contribute to further vulnerability. The scientific goal of this proposed PhD is to identify these scar effects by examining which features follow a first depressive episode in adolescent individuals and which act as vulnerability markers predicting future recurrence of illness.
Based on a developmental perspective, this PhD will target the period immediately following the first depressive episode in adolescence, to examine the dynamic change of risk and resilience mechanisms over this critical time. This is built upon our two current Wellcome Trust funded studies (led by the applicant) examining how biological and psychosocial risk mechanisms emerge in adolescence prior to illness onset. Together, our findings will make a significant scientific contribution regarding the mechanisms that underpin the occurrence and recurrence of adolescent depression, a question that has been identified by patients, carers, and mental health professionals as the top priority of depression research [6].We will also take an interdisciplinary approach, examining across biological, neural-cognitive and psychosocial mechanisms. This holistic approach, supported by an interdisciplinary supervision team situated in the unique multidisciplinary environment at the University of Edinburgh, is important in bridging the gaps in knowledge due to traditional unhelpful disciplinary divides. This study will have an impact on the development of better treatments that can build long term resilience against recurrence of illness, improving quality of life from a young age.