| The main study (Study 1) consists of a randomized controlled trial comparing two versions of a new preventive training program targeting excessive rumination and worry versus a no-training control group. The study aims to test proof-of-principle for these novel approaches and to investigate their feasibility and acceptability to the relevant population. Participants will be adolescents and young adults who show heightened levels of rumination/worry and can therefore be expected to be at elevated risk for future depression and anxiety disorders. Eligible participants will be identified via screening at secondary schools and institutions of higher education. The main inclusion criterion will be scores above the 75% percentile on two validated questionnaire measures of worry and rumination (Penn State Worry Questionnaire; Response Style Questionnaire). Exclusion criteria will be clinically relevant levels of depression or anxiety. Participants will be randomly assigned to (1) a rumination-focused cognitive-behavioral training delivered in a group format; (2) a rumination-focused cognitive-behavioral training delivered via the internet and (3) a no-training control condition. The main outcome measures (rumination/worry and emotional problems) will be assessed pre-training, post-training and at 3 months and 1 year follow-up. The rumination-focused cognitive behavioral training delivered in a group setting will be a modified version of a protocol developed by Watkins and colleagues that has been shown to effectively reduce levels of worry/ rumination and prevent relapse in individuals with residual depression. The training is based on (1) experimental research showing that dysfunctional forms of rumination are characterized by an abstract and evaluative style of processing, whereas functional forms processing are more concrete and process-focused and (2) evidence showing that rumination/worry are forms of avoidance. The training uses psycho-education, functional analysis, group discussion, experiential/imagery exercises and behavioral experiments designed to both facilitate a shift from dysfunctional ruminative thinking into the more helpful concrete thinking style and to increase approach behaviors. The internet-based training will be based on the same principles as the group training and will consist of the same basic strategies and exercises. However, no direct contact with a trainer or other participants will take place. The modules of the internet-based training will guide participants in a step-by-step way through the psychoeducation and the exercises practised in the rumination-focused approach, as well as allow participants to set and monitor their own homework. The implementation of a targeted prevention program for adolescents and young adults with high trait levels of rumination/worry requires the easy identification of individuals in need for the intervention. Therefore, Study 2 aims to develop and evaluate a short 4-item screening measure for excessive rumination/worry that can be used to identify individuals at need of preventive interventions. The data collection will be embedded within the main randomized controlled trial and conducted in parallel with this main study. |
