AUTHOR=Asikainen Henna , Hailikari Telle , Katajavuori Nina TITLE=Explaining the changes in procrastination in an ACT-based course – psychological flexibility and time and effort management as mediators JOURNAL=Frontiers in Psychology VOLUME=Volume 15 - 2024 YEAR=2024 URL=https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2024.1331205 DOI=10.3389/fpsyg.2024.1331205 ISSN=1664-1078 ABSTRACT=The aim of our study is to explore the relationship between procrastination, time management skills and psychological flexibility and the changes in them during an Acceptance and Commitment therapy (ACT)-based course that included time management training. We also explored the effects of time management skills and psychological flexibility on procrastination. The study used an experimental design in an ACT-based well-being course that included time management training. The participants were 109 students taking the course and 27 waiting list students. Our results show that time management skills, psychological flexibility and procrastination were related to each other, and all changed during the course. In addition, change in both time management and psychological flexibility had an impact on the change in procrastination during the course. The results show that both time management and psychological flexibility influence the change in procrastination during an ACTbased course.