Symptom provocation in obsessive-compulsive disorder: Validation of the Braga Obsessive Compulsive image set (BOCIS)

Symptom provocation paradigms are paramount to understand a heterogeneous disorder as obsessive-compulsive disorder (OCD). The main aim of our work was to develop and validate an open-access set of OCD-related images comprising three main subtypes: washing, checking, and symmetry. Twenty-six OCD patients and 25 controls provided valence and arousal ratings for a set of OCD-related, aversive, and neutral images. Linear mixed model analyses were used to estimate the main effects of group, image category, and group-image category interaction in image ratings. All main effects were found to be significant for both arousal and valence ratings, except for the group in arousal ratings. Path analysis confirmed our hypothesis that the OCI-R subscales influenced the subjective ratings of the corresponding image categories, particularly among patients. Independent samples t-tests were performed for each OCD picture to compose the set. Arousal demonstrated a greater capacity to distinguish controls and patients, thus sustaining our choice of using these ratings for the final Braga Obsessive-Compulsive Image Set (BOCIS). Our study demonstrated that the stimuli of the BOCIS reliably portray OCD-like triggers for washing, checking and symmetry subtypes. Its open-access availability will facilitate significant progress in both clinical and research settings.