Protocol for a randomised controlled trial investigating an intervention to boost decentering in response to distressing mental experiences during adolescence: the decentering in adolescence study (DECADES).

INTRODUCTION: Decentering describes the ability to voluntarily adopt an objective self-perspective from which to notice internal, typically distressing, stressors (eg, difficult thoughts, memories and feelings). The reinforcement of this skill may be an active ingredient through which different psychological interventions accrue reductions in anxiety and/or depression. However, it is unclear if decentering can be selectively trained at a young age and if this might reduce psychological distress. The aim of the current trial is to address this research gap. METHODS AND ANALYSIS: Adolescents, recruited from schools in the UK and Ireland (n=57 per group, age range=16-19 years), will be randomised to complete 5 weeks of decentering training, or an active control group that will take part in a combination of light physical exercise and cognitive training. The coprimary training outcomes include a self-reported decentering inventory (ie, the Experiences Questionnaire) and the momentary use of decentering in response to psychological stressors, using experience sampling. The secondary mental health outcomes will include self-reported inventories of depression and anxiety symptoms, as well as psychological well-being. Initial statistical analysis will use between-group analysis of covariance to estimate the effect of training condition on self-rated inventories, adjusted for baseline scores. Additionally, experience sampling data will be examined using hierarchical linear models. ETHICS AND DISSEMINATION: This study was approved by the Cambridge Psychology Research Ethics Committee, University of Cambridge (PRE.2019.109). Findings will be disseminated through typical academic routes including poster/paper presentations at (inter)national conferences, academic institutes and through publication in peer-reviewed journals. TRIAL REGISTRATION NUMBER: ISRCTN14329613.

Decentering as a core component in the psychological treatment and prevention of youth anxiety and depression: a narrative review and insight report.

Decentering is a ubiquitous therapeutic concept featuring in multiple schools of psychological intervention and science. It describes an ability to notice to day-to-day psychological stressors (negative thoughts, feelings, and memories) from an objective self-perspective and without perseverating on the themes they represent. Thus, decentering dampens the impact and distress associated with psychological stressors that can otherwise increase mental ill health in vulnerable individuals. Importantly, the strengthening of decentering-related abilities has been flagged as a core component of psychological interventions that treat and prevent anxiety and depression. We provide an in-depth review evidence of the salutary effects of decentering with a special focus on youth mental health. This is because adolescence is a critical window for the development of psychopathology but is often under-represented in this research line. A narrative synthesis is presented that integrates and summarizes findings on a range of decentering-related abilities. Section 1 reviews extant conceptualizations of decentering and data-driven approaches to characterize its characteristic. A novel definition is then offered to guide future empirical research. Section 2 overviews laboratory-based research into the development of decentering as well as its relationship with anxiety and depression. Section 3 examines the role decentering-related skills play in psychological interventions for anxiety and depression. Critically, we review evidence that treatment-related increases in decentering predict latter reductions in anxiety and depression severity. Each section highlights important areas for future research. The report concludes by addressing the vital questions of whether, how, why and when decentering alleviates youth anxiety and depression.