The goal of the project is to develop a brief, manualised intervention for adolescent depression that targets anhedonia through harnessing the ability to imagine positive events. This intervention is designed to be delivered in the school environment by practitioners without extensive training. A feasibility randomised controlled trial (RCT) will be conducted by the doctoral student in the proposed project to assess the acceptability of this intervention in schools.~Principal Research Questions:~The primary question is whether a brief, structured intervention to reduce anhedonia symptomatology in depressed adolescents is feasible and acceptable. This trial will inform whether a full-scale efficacy trial is warranted and provide estimates of effect sizes. The trial's primary aims are:~To evaluate recruitment and retention for a future efficacy RCT, for example recruitment rates for schools and participants, attrition rates and outcome measure completion.~To gather descriptive data on symptom change to inform future estimates of the number of participants required for a fully powered efficacy RCT.~Background:~Depression is a major public health concern, associated with severe and long-lasting impairment. Many cases of depression start in adolescence with adolescent-onsets associated with greater illness burden than adult-onsets. Whilst psychological intervention in adolescence may prevent the persistence of depression into adulthood and its debilitating consequences, these are rarely available. There is also a consistent failure to produce well-replicated efficacious psychological and pharmacological treatments in adolescent depression. In adults, treatment innovation techniques have tried to focus on specific features, such as anhedonia, that are associated with severity and treatment response. Anhedonia, a loss of pleasure or lack of reactivity to pleasurable stimuli, is a hallmark feature of depression. It is associated with brain reward systems and, in youth, predicts illness severity, suicidality and poor treatment response better than other symptoms of depression. Given these findings and that brain reward systems underlying anhedonia are maturing and stabilising in adolescence focussing on the up-regulation of positive emotion during this developmental juncture could be a beneficial therapeutic approach.~Traditionally, psychological interventions for depression target negative affect in the present and/or past. However, potential deficits in processing positive information, in particular positive future-directed cognitions, may be crucial to alleviate anhedonia and produce enhanced treatment response. Mental imagery is suggested to be a powerful tool to promote changes in positive prospective cognitions. In adolescence, this approach could be particularly beneficial as it is a period when future orientation increases and when individuals rely more on imagery for processing and skill acquisition than in adulthood. Although research in this area in adolescent depression is limited, our findings suggest that having more vivid positive future imagery can protect against depressive symptoms in youth following a recent negative life event. Through a National Institute for Health and Care Research (NIHR) funded project, the investigators have developed a novel brief therapy manual and implementation protocol for adolescents using co-design methodology (Research Ethics Sub-Committee ref: HR-15/16-3548; Project ID: 14884). This targets mental imagery in general (rather than positive future mental imagery, in particular) to attenuate depression symptoms. A case series of 9 participants suggests that this intervention is acceptable and may have clinical utility. However, this intervention targets depression generally rather than anhedonia specifically and has only been delivered by an experienced child clinical psychologist. Therefore, the aim of this project is to develop a brief, manualised intervention that targets anhedonia in adolescents with depression, which can be delivered in schools by practitioners without extensive training.~Intervention:~The investigators will adapt our existing therapy manual to create a manualised protocol that more specifically targets positive future imagery to reduce anhedonia. The existing intervention is a four-session programme involving memory specificity training to increase specificity and access to autobiographical memories, imagery re-scripting to reduce distress from negative images and building of positive images. In order to tackle anhedonia more specifically, the investigators will replace negative imagery re-scripting with elements that target up-regulation of positive emotion and expand and elaborate on positive future imagery generation. These changes will also be informed through discussion with other experts and service-user consultants.~Feasibility randomised controlled trial: As this study will assess feasibility and not efficacy, a power calculation to determine sample size is not appropriate. The sample size (n=32, 16 in each arm) was determined with reference to good practice recommendations. The control condition will be 'non-directive supportive therapy', consisting of individual sessions to provide empathy and emotional support, discussion of participant-initiated options for addressing problems and monitoring of depression. The number and frequency of sessions will be matched across groups to control for non-specific factors contributing to change (e.g. passage of time, rapport with an empathic adult). Blind pre/post assessments will be conducted for all participants.
Depression is a common mental health problem that often begins during adolescence. Onset during adolescence can be disruptive to schoolwork and social relationships and if left untreated can lead to recurrence during adulthood, as well as the development of other mental health problems. Current treatments for depression (for both adults and young people) largely focus on reducing low mood and do not effectively tackle the other hallmark symptom of depression, anhedonia, which is characterised as a loss of enjoyment/ pleasure for previously enjoyed activities. Anhedonia is associated with increased risk of suicidality, so should be an important treatment target. Whilst some adult treatments are beginning to address anhedonia, little research has focussed on young people. It cannot be assumed that adult treatments will work identically in young people, particularly s their brains are still maturing compared to adults. The aim of this study is to complete a randomised feasibility trial, to see if it is possible to run a brief talking therapy for anhedonia in adolescent depression, by targeting one promising cognitive factor known to contribute to low positive affect: positive future mental imagery