Intrusive thoughts and rumination in young people with depression, PTSD and a non-clinical control group.

Introduction: Intrusive thoughts (Ciesla & Roberts, 2007; Tanaka et al., 2006) and rumination (Nolen-Hoeksema, Parker & Larson, 1994; Papageorgiou & Wells, 2004) have been found to play a role in maintaining depression in adult samples, however little is known about the experience of these phenomena in young people. Models of post-traumatic stress disorder (PTSD) also propose a major role for evaluative thoughts in the maintenance of PTSD (Ehlers & Clark, 2000). Aim: This thesis portfolio focused on the relationship between depression and PTSD and both rumination and intrusive thoughts, and comprised two studies. Method: The first study was a meta-analysis (n=5) exploring levels of rumination in young people with depression and non-clinical young people to assess association between depression and rumination. The second study used a between-group, cross-sectional, quantitative design to investigate the experience of intrusive thoughts in 11-18 year olds with depression (n=11), PTSD (n=13) and a non-clinical control (n=28) group was investigated. Young people completed a structured telephone interview concerning the experience, frequency, duration, associated emotion, appraisal and coping style of intrusive thoughts. Results: The meta-analysis found that rumination is strongly related to depression in young people compared to non-clinical controls. In the second study, intrusive thoughts were found to be common in all three groups, but were found to be a more common experience in the depression group. Both of the clinical groups appraised their thought more negatively and experienced them as more affect-laden than the non-clinical group. All three groups rated rumination as being the least helpful coping style. Discussion: In the discussion the theoretical implications of the research findings for both the Response Styles theory and the PTSD models are explored. Clinical implications, including the potential for psychological interventions to consider teaching young people more helpful coping strategies to manage their intrusive thoughts, and limitations of the study are considered