Background: Association splitting is a cognitive technique that targets obsessions in obsessive-compulsive disorder (OCD) by weakening biased semantic associations among OCDrelevant concepts.
Objective: In this systematic review, we examine studies on the efficacy of association splitting for reducing OCD symptoms. Methods: Following PRISMA guidelines, six studies were included, with diversity in sample characteristics, mode of administration (i.e., self-help vs therapist-assisted), language of administration, comparator groups, etc. Results: Results indicated that association splitting, as a self-help intervention, was efficacious in reducing overall OCD symptom severity, specific OCD symptoms (i.e., sexual obsessions), subclinical unwanted intrusions, and thought suppression, with small-to-large effect sizes (e.g., across relevant studies, ds = .28-1.07). Findings were less clear when association splitting was administered on a therapist-assisted basis as an add-on to standard cognitive-behavior therapy (CBT). Nonetheless, across studies, the majority of participants reported high acceptability, ease of comprehension, and adherence to daily association splitting practice. Conclusion: Although association splitting is an efficacious and acceptable self-help intervention for OCD symptoms, future studies should include appropriate comparison groups, conduct longitudinal assessments, examine efficacy for different symptom dimensions, and assess changes in semantic networks as proof of mechanistic change. There should also be greater representation of marginalized groups in future studies to assess association splitting’s utility in circumventing barriers to face-to-face CBT. Ethical considerations are also discussed.Keywords: Obsessive-compulsive disorder, association splitting, semantic network, intervention, psychotherapy, cognitivebehavior therapy.