The gist of **Rumination-Focused Cognitive Behavioral Therapy** (RFCBT: Watkins et al., 2007; Watkins et al., 2011) is to replace abstract (evaluative) thoughts (i.e., thinking in terms of broad “Why”-questions, like “Why is this happening?” and “Why can’t I handle things better?”) with a more concrete and solution-focused style (e.g., “HOW can I try to solve this?”), resulting in more constructive thinking (Watkins, 2016). This treatment is expected to be highly compatible with Cognitive Control Training (CCT). Theoretically, the ability to shift to a more helpful style of thinking, away from Repetitive Negative Thinking (RNT: Ehring & Watkins, 2008), is facilitated by training Cognitive Control. To test this hypothesis, we have set up a collaboration with **PraxisP**, a treatment center associated with **KU Leuven**. Among other interventions, PraxisP offers a group-based version (Topper, Emmelkamp, Watkins, & Ehring, 2017) of RFCBT. People following this program will be given the opportunity to participate in our study, for which they will receive access to a website designed for (the investigation of) online CCT. More information on the design, measures and operationalization of the CCT can be found under the method component coupled to this project. *Ehring, T., & Watkins, E. R. (2008). Repetitive Negative Thinking as a Transdiagnostic Process. International Journal of Cognitive Therapy, 1(3), 192–205. https://doi.org/10.1680/ijct.2008.1.3.192* *Topper, M., Emmelkamp, P. M. G., Watkins, E., & Ehring, T. (2017). Prevention of anxiety disorders and depression by targeting excessive worry and rumination in adolescents and young adults: A randomized controlled trial. Behaviour Research and Therapy, 90, 123–136. doi:10.1016/j.brat.2016.12.015* *Watkins, E. R. (2016). Rumination-Focused Cognitive-Behavioral Therapy for Depression. New York: The Guildford Press.* *Watkins, E. R., Mullan, E., Wingrove, J., Rimes, K., Steiner, H., Bathurst, N., … Scott, J. (2011). Rumination-focused cognitive-behavioural therapy for residual depression: Phase II randomised controlled trial. British Journal of Psychiatry, 199(4), 317–322. https://doi.org/10.1192/bjp.bp.110.090282* *Watkins, E. R., Scott, J., Wingrove, J., Rimes, K., Bathurst, N., Steiner, H., … Malliaris, Y. (2007). Rumination-focused cognitive behaviour therapy for residual depression: A case series. Behaviour Research and Therapy, 45(9), 2144–2154. https://doi.org/10.1016/j.brat.2006.09.018*