Words may not be enough! No increased emotional Stroop effect in obsessive-compulsive disorder

Conflicting evidence has been obtained whether or not patients diagnosed with obsessive-compulsive disorder (OCD) share an attentional bias towards disorder-related stimuli. Some of these inconsistencies can be accounted for by suboptimal stimuli selection. In consideration of the heterogeneity of OCD, we investigated Stroop interference effects for two classes of OCD items (i.e., washing and checking) in 23 OCD patients and 23 healthy controls. In order to cover prevalent OCD concerns, item compilation was based on experts' appraisals. Patients neither displayed greater immediate as well as delayed Stroop interference nor any bias for OCD and subtype-congruent stimuli. On the contrary, for washing-related items, OCD patients, and here especially washers, displayed facilitation relative to healthy controls. Although the present study at first sight refutes the notion of an attentional bias in OCD in contrast to other anxiety disorders, several potential moderators need to be considered before this account is ultimately dismissed. In particular, an attentional bias may only be elicited using visual material that is more attention-grabbing than verbal stimuli. Finally, blockwise instead of random item administration and greater consideration of individual relevance may be crucial prerequisites for the effect to emerge.