Gamified Combined Cognitive Bias Modification in Adults Diagnosed With OCD: Randomized Controlled Trial

A gamified version of the combined cognitive bias modification (CBM-C) intervention, which includes both attention and interpretation bias modification tasks. The attention component is a modified dot-probe task, and the interpretation component consists of OCD-related scenarios with word-completion exercises. Gamification elements such as feedback and visual rewards are embedded to enhance motivation and engagement. The presentation order of the two intervention components will be counterbalanced: half of the participants will receive the attention bias task first followed by the interpretation task; the other half will receive the interpretation task first followed by the attention bias task. The intervention is delivered via mobile phone in eight sessions over four weeks (two sessions per week).

A standard version of the combined cognitive bias modification (CBM-C) intervention, consisting of attention and interpretation bias tasks without gamification features. The attention task is a modified dot-probe paradigm, and the interpretation task involves OCD-related scenarios followed by word-completion exercises. The presentation order of the two intervention components will be counterbalanced: half of the participants will receive the attention bias task first followed by the interpretation task; the other half will receive the interpretation task first followed by the attention bias task. The intervention is delivered via mobile phone in eight sessions over four weeks (two sessions per week).

A placebo version of the standard CBM-C intervention that retains the same structure and timing but omits all active bias modification elements. The attention task (modified dot-probe) presents probes equally behind threat and neutral stimuli, and the interpretation task includes OCD-related scenarios with word-completion items that lead to neutral outcomes. No manipulations are applied to shift cognitive bias. The presentation order of the two intervention components will be counterbalanced: half of the participants will receive the attention bias task first followed by the interpretation task; the other half will receive the interpretation task first followed by the attention bias task. The intervention is delivered via mobile phone in eight sessions over four weeks (two sessions per week).