Developing image sets for inducing obsessive-compulsive checking symptoms

Abstract

Visual stimuli are often used for obsessive-compulsive (OC) symptom provocation in research studies. We tested the induction of anxiety and OC checking symptoms across different types of checking provocation stimuli in three populations: individuals with obsessive compulsive disorder (OCD), individuals with checking symptoms but without a diagnosis of OCD, and control individuals with neither checking symptoms nor a clinical diagnosis. One set of provocative images depicted objects that are commonly associated with checking anxiety. Another set ('enhanced provocative images') depicted similar objects but also included contextual cues suggesting a specific harmful scenario that could occur. As expected, the enhanced provocative images were more effective at inducing anxiety and OC symptoms than the standard provocative images. Future studies requiring checking symptom provocation should therefore consider incorporating similarly suggestive images. Individuals with clinical OCD reported the greatest provocation in response to these images, followed by those with nonclinical checking, followed by control individuals. Thus, these stimuli are able to provoke OC checking symptoms and anxiety differentially across groups, with the intensity of provocation reflecting diagnostic status. All groups demonstrated a similar qualitative pattern of provocation across images. Finally, in all groups, reported anxiety closely tracked intrusive thoughts and checking urges.

Keywords: Anxiety [F01.470.132]; Compulsive Behavior [F01-145-527-100]; Obsessive Behavior [F01.145.126.950]; Obsessive-Compulsive Disorder [F03-080-600].

Figure 1:

Two examples of provocative images (left panel) and their matched enhanced provocative images (right panel).

Figure 2:

Illustration of a single trial for a provocative (left side) or enhanced provocative (right side) image. Each trial began with instructions (2.5 s), which were immediately followed by three presentations of a picture along with rating prompts (anxiety, intrusive thoughts, compulsive urges). Participants were instructed to respond to each statement using a Likert scale from 1–7 where 1 = Strongly Disagree and 7 = Strongly Agree. Presentation order was random.

Figure 3.

Effects of group and stimulus type on anxiety (panels A and B) and correlations of anxiety ratings between groups (panels C and D). (A) Plot showing anxiety ratings of control participants (empty circles), participants with nonclinical checking (grey squares), and participants with OCD (black circles) across all images in the neutral, provocative, and enhanced provocative categories (left to right). (B) Mean anxiety ratings for control participants (white), participants with nonclinical checking (grey), and participants with OCD (black) for images in the neutral, provocative, and enhanced provocative categories (left to right). (C, D) Scatter plots of anxiety ratings of participants with OCD versus participants with nonclinical checking (panel C), and of anxiety ratings of participants with nonclinical checking versus control participants (panel D). The solid line indicates the line of best fit; the dotted line shows the line x=y. In both cases, note that the line of best fit is approximately parallel to x=y, but raised, indicating consistently greater anxiety both in the OCD group compared to the nonclinical checking group (panel C), and in the nonclinical checking group compared to the control group (panel D). In both panels C and D, anxiety ratings for the different stimulus types are color coded, with enhanced provocative images (black circles) tending to elicit the most anxiety, followed by provocative images (grey circles), followed by neutral images (empty circles).

Figure 4:

The average anxiety rating for each image plotted against the average OC symptom rating for the same image in (A) control group, (B) the nonclinical checking group, and (C) the OCD group. Neutral images are shown with empty circles, provocative images with grey circles, and enhanced provocative images with black circles. In all groups, strong relationships are apparent between anxiety ratings and composite OC ratings. As the scales of the axes are held constant, the spread away from the origin in panel C reflects greater anxiety and OC symptoms in the OCD group