Perceptual properties of obsessive thoughts are associated with low insight in obsessive-compulsive disorder.

Obsessions are traditionally defined as bothersome and repetitive thoughts that the patient is unable to resist. Preliminary evidence suggests that in a subgroup of patients with obsessive-compulsive disorder (OCD), obsessions are experienced as partially perceptual. The present study explored the frequency of perceptually laden obsessions and their relationship with illness insight and depression. Twenty-six patients with OCD were administered the newly developed Sensory Properties of Obsessions Questionnaire. Participants were asked to endorse on a 5-point Likert scale whether their obsessions were associated with perceptual features. Participants showed moderate symptom severity. A total of 73% affirmed that their obsessions contained perceptual features. The predominant perceptual channels were visual, tactile, and somatic (i.e., bodily sensations). The extent of perceptual aspects associated with obsessions was strongly correlated with lack of insight (Yale-Brown Obsessive-Compulsive Scale item 11) but not depression severity. The present study suggests that obsessive thoughts are frequently accompanied by perceptual sensations, which concurs with models assuming a continuum between hallucinations and intrusions. Apparently, the more "real" or authentic the obsessive thought is experienced, the less the afflicted person is able to dismiss its content as fully irrational or absurd.