Leaves on the Stream: An ACT Cognitive Defusion Exercise for Letting Go of Unhelpful Thoughts
Leaves on the Stream is an Acceptance and Commitment Therapy (ACT) practice that helps you notice thoughts without having to fight them, follow them, or believe everything they say. In this exercise, you might imagine sitting beside a stream and placing each thought, worry, memory, image, judgment, prediction, urge, or feeling onto a leaf as it floats by. Some leaves may move quickly. Others may linger. The practice is not to control the stream, but to notice what appears and gently return to watching. You might begin by pausing for a few minutes, settling your attention, and gently naming whatever shows up before placing it on a leaf. In ACT, this is called cognitive defusion, which means creating space between you and your thoughts so they can be seen as thoughts rather than treated as facts, commands, or the whole truth. This kind of practice supports psychological flexibility, which is the ability to stay present, make room for difficult inner experiences, and choose actions that fit your values. Research on ACT and cognitive defusion suggests that learning to relate differently to thoughts can reduce their believability and emotional pull while supporting more flexible, values-based responding (Assaz et al., 2023; Larsson et al., 2016; Masuda et al., 2004; 2010; Webster, 2011).
This skill can be especially useful when thoughts feel loud, sticky, repetitive, or overwhelming. You are not trying to empty your mind, make thoughts disappear, or force yourself to feel calm. Instead, you are practicing a different relationship with your mind: noticing what shows up without automatically obeying it, avoiding it, arguing with it, or trying to solve it immediately. If the same thought comes back, you can place it on another leaf without needing to debate it, push it away, or decide what it means right away. If your attention wanders, that does not mean you are doing it wrong. Noticing the wandering and returning to the practice is part of the skill. Leaves on the Stream can also be adapted: eyes can stay open, the image can be changed, or the practice can become more grounded and sensory if visualization feels uncomfortable. Over time, this practice can help you notice the content of your mind with enough space to choose what matters next, rather than reacting only from fear, shame, urgency, or self-criticism (Assaz et al., 2023; Larsson et al., 2016; Masuda et al., 2010).
References
Assaz, D. A., Tyndall, I., Oshiro, C. K. B., & Roche, B. (2023). A process-based analysis of cognitive defusion in acceptance and commitment therapy. Behavior Therapy, 54(6), 1020-1035. https://doi.org/10.1016/j.beth.2022.06.003
Larsson, A., Hooper, N., Osborne, L. A., Bennett, P., & McHugh, L. (2016). Using brief cognitive restructuring and cognitive defusion techniques to cope with negative thoughts. Behavior Modification, 40(3), 452-482. https://doi.org/10.1177/0145445515621488
Masuda, A., Hayes, S. C., Sackett, C. F., & Twohig, M. P. (2004). Cognitive defusion and self-relevant negative thoughts: Examining the impact of a ninety year old technique. Behaviour Research and Therapy, 42(4), 477-485. https://doi.org/10.1016/j.brat.2003.10.008
Masuda, A., Twohig, M. P., Stormo, A. R., Feinstein, A. B., Chou, Y., & Wendell, J. W. (2010). The effects of cognitive defusion and thought distraction on emotional discomfort and believability of negative self-referential thoughts. Journal of Behavior Therapy and Experimental Psychiatry, 41(1), 11-17. https://doi.org/10.1016/j.jbtep.2009.08.006
Webster, M. (2011). Introduction to acceptance and commitment therapy. Advances in Psychiatric Treatment, 17(4), 309-316. https://doi.org/10.1192/apt.bp.107.005256
