Studies showing interference with color naming threat-related words in patients with anxiety disorders suggest a bias towards processing threatening material in these patients. We assessed the specificity of this finding to anxiety disorders and to threatening stimuli by administering Stroop cards with a variety of types of emotional stimuli to 24 panic disorder patients with no history of major depression, 30 patients with major depression and no history of panic attacks and 25 controls with no history of an axis I disorder. Our findings suggest that the abnormal information processing seen in panic disorder may be characterized by a more general bias towards processing emotional stimuli than previously thought. They also suggest that this more general bias may illustrate differences in information processing in panic disorder and major depression.