Most people experience an occasional “what if?” thought and move on. With OCD, however, a possibility can become an exhausting search for certainty. You may replay conversations, review memories, check sensations, search online, or ask others for reassurance—only to discover that the doubt eventually returns.
Inference-Based Cognitive Behavioral Therapy, or I-CBT, offers a distinctive way of understanding this cycle. Rather than focusing only on whether a feared outcome might occur, I-CBT examines how the mind moved from what is actually known into an imagined possibility—and why that possibility began to feel important enough to investigate.
Obsessional doubt can make an imagined possibility feel as important as something supported by evidence. I-CBT helps identify when reasoning has shifted away from present reality and toward a hypothetical story, allowing people to begin responding differently to doubt.
OCD can make uncertainty feel urgent, as though every possibility must be analyzed before you can safely move forward. Treatment can help you recognize when a hypothetical possibility has become obsessional doubt—and practice returning attention to what is actually known rather than continuing the search for absolute certainty.
Everyday worry often begins with a realistic uncertainty. Obsessional doubt can work differently: the mind generates a hypothetical possibility and then demands proof that it did not happen. Because absolute certainty about an imagined scenario is rarely attainable, attempts to resolve the doubt can lead to more questions rather than lasting relief.
Reassurance, checking, reviewing memories, researching, and analyzing may temporarily reduce anxiety. Yet the relief often fades and another question appears: “But what if I missed something?” I-CBT focuses on understanding how the doubt was constructed rather than repeatedly trying to prove that every feared possibility is impossible.
I-CBT examines the reasoning process that can transform a possibility into an obsessional doubt. Therapy may identify the original doubt, explore the narrative the mind constructed around it, and notice where attention shifted from available evidence toward imagination. Clients learn about inferential confusion, including how a hypothetical possibility can begin to function as though it were evidence. Treatment then emphasizes reconnecting with sensory information, memory, context, and common sense. The goal is not reassurance, but a more grounded way of responding when the mind produces another compelling “what if?”
Research on I-CBT has grown, with clinical trials finding meaningful improvements in OCD symptoms among participants receiving the treatment. Recent randomized studies have compared I-CBT with other psychological treatments, including conventional CBT, while research continues to examine inferential confusion as a potential mechanism of change. Findings are promising, but the literature also contains important limitations and mixed conclusions. I-CBT should therefore be understood as an evidence-informed approach with a growing research base rather than a replacement for the broader evidence supporting CBT with exposure and response prevention. Treatment decisions should be individualized to each person's symptoms and clinical needs.
References
Aardema, F., O’Connor, K. P., Delorme, M.-E., & Audet, J.-S. (2017). The inference-based approach (IBA) to the treatment of obsessive-compulsive disorder: An open trial across symptom subtypes and treatment-resistant cases. Clinical Psychology & Psychotherapy, 24(2), 289–301. https://doi.org/10.1002/cpp.2024 (PubMed)
Aardema, F., O’Connor, K. P., Emmelkamp, P. M. G., Marchand, A., & Todorov, C. (2022). Evaluation of inference-based cognitive-behavioral therapy for obsessive-compulsive disorder: A multicenter randomized controlled trial with three treatment modalities. Psychotherapy and Psychosomatics, 91(5), 348–359. (PubMed)
Julien, D., O’Connor, K. P., & Aardema, F. (2016). The inference-based approach to obsessive-compulsive disorder: A comprehensive review of its etiological model, treatment efficacy, and model of change. Journal of Affective Disorders, 202, 187–196. https://doi.org/10.1016/j.jad.2016.05.060 (ScienceDirect)
Myers, N. S., & Abramowitz, J. S. (2025). Unpacking inferential confusion: A critical review of the inference-based approach to obsessive-compulsive disorder. Journal of Obsessive-Compulsive and Related Disorders. https://doi.org/10.1016/j.jocrd.2025.100983 (ScienceDirect)
Wolf, N., van Oppen, P., Hoogendoorn, A. W., van den Heuvel, O. A., van Megen, H. J. G. M., Broekhuizen, A., Kampman, M., Cath, D. C., Schruers, K. R. J., van Es, S. M., Opdam, T., van Balkom, A. J. L. M., & Visser, H. A. D. (2024). Inference-based cognitive behavioral therapy versus cognitive behavioral therapy for obsessive-compulsive disorder: A multisite randomized controlled non-inferiority trial. Psychotherapy and Psychosomatics, 93(6), 397–411. https://doi.org/10.1159/000541508 (PubMed)
Editorial note for Anxiety Arizona: I would publish this with the article categorized under OCD / Obsessive-Compulsive Disorder / Cognitive Behavioral Therapy, rather than general anxiety. That will make the clinical positioning much stronger and allow the article to target searches around obsessional doubt, “what if” OCD, inferential confusion, and inference-based CBT.
