Emotional interference in obsessive-compulsive disorder: a neuropsychological study using optimized emotional Stroop test

Contents related to threat and associated cognitive processes are proposed to be the central characteristic of obsessive-compulsive disorder (OCD) according to 'threat-relatedness hypothesis'. However, evidence for attention bias toward emotionally salient stimuli using the emotional Stroop test is equivocal. This discrepancy could be due to methodological issues, mainly differences in the lexical characters of words. Fifty Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) OCD patients (23 washers and 27 checkers) and 50 age-, handedness- and sex-matched healthy controls were examined with an optimized version of the emotional Stroop test (i.e., with lexically matched words) and color-Stroop test. Twenty-four patients were clinically symptomatic and 26 were remitted. OCD patients had significantly higher attention bias only for negative OCD stimuli as calculated by negatively valenced OCD interference score but not for neutral or non-OCD emotional stimuli. Symptomatic patients had significantly higher bias, but not the remitted patients. There were no significant correlations between other illness-related variables (age at onset, illness duration, and medication dose) and Stroop test performance. Study findings suggest the presence of selective emotional bias for OCD relevant stimuli in these patients and this bias is potentially related to symptomatic status. These observations are in tune with the threat-relatedness hypothesis.