Context: Attentional bias to disease-relevant emotional cues is considered to be pathogenetically relevant in anxiety disorders.
Objective: To investigate functional neural correlates and disease specificity of attentional bias across different anxiety disorders.
Design: A cognitive and emotional Stroop task, consisting of congruent and incongruent color words, obsessive-compulsive disorder (OCD)-related and panic-related negative words, and neutral words, was used in 3 patient groups and a control group during functional magnetic resonance imaging.
Setting: Academic outpatient department for anxiety disorders.
Patients and participants: Medication-free patients with OCD (n = 16), panic disorder (PD) (n = 15), and hypochondriasis (n = 13) and 19 controls.
Main outcome measure: Voxel-wise analyses of cerebral blood flow changes for contrasts of interest (incongruent vs congruent color words, OCD-related vs neutral words, and panic-related vs neutral words) within and between groups.
Results: During incongruent vs congruent color naming, all patient groups recruited additional posterior brain regions relative to controls, but performance was impaired only in OCD. In OCD, color naming OCD-related, but not PD-related, words correlated with increased activation of frontal-striatal and temporal regions, although performance was unimpaired. In contrast, in PD, increased frontal-striatal involvement was found during color naming both OCD-related and panic-related words. In PD, color naming panic-related words was slowed and correlated with increased activation of the right amygdala and hippocampus. Patients with hypochondriasis showed a similar activation pattern to patients with PD.
Conclusions: Our results support the hypothesis of increased distractibility for irrelevant information in patients with OCD, PD, and hypochondriasis associated with frontal-striatal and limbic involvement compared with controls. Although patients with OCD did not display an attentional bias in behavior relative to controls, there was a clear, specific neural response during color naming OCD-related words, involving mainly ventral brain regions. In contrast, generalized emotional interference effects were found in PD and hypochondriasis, involving ventral and widespread dorsal brain regions, reflecting not only unconscious emotional stimulus processing but also increased cognitive elaboration.