Background Obsessive-compulsive disorders (OCD) are characterized by intrusive thoughts or images (obsessions), which increase anxiety, and by repetitive or ritualistic actions (compulsions), which decrease anxiety. The classification of obsessive-compulsive disorders includes the idea of an overlap with anxiety disorders, especially regarding the use of repetitive rituals to decrease anxiety in the sense of a form of a maladaptive homeostatic regulation. In addition there is a common overlap with anxiety disorders and depression. other psychiatric disorders significant differences in heartbeat perception ability have been observed in several clinical samples: Many studies (Eley, Stirling, Ehlers, Gregory, & Clark, 2004; Pineles & Mineka, 2005;) have shown that interoceptive sensitivity is closely associated with anxiety disorders. Interestingly Dunn and colleges (2007) found that interoceptive sensitivity is reduced in depressed patients. Deficits in interoceptive sensitivity might therefore play an important role in the etiology and maintenance of OCDs. The question as to whether interoceptive sensitivity measured by a heartbeat perception task is reduced in obsessive compulsive disorders is still open. Methods: Based on this we conducted a study to have a closer look at the ongoing bodily processes in a sample of patients with OCD using a well-validated heartbeat perception task (Schandry, 1981). Measures included the State Trait Anxiety Inventory (STAI) and the Beck Depression Inventory (BDI). Symptoms of the OCD were assed with the Yale-Brown Obsessive Compulsive Scale (YBOCS). The main objective of the present study was to investigate the degree of interoceptive awareness in OCD. Additionally we examined the interoceptive awareness over the time of the ongoing therapy. As former data indicated that interoceptive sensitivity is related to anxiety and depression these variables were also assessed and included as possible mediators for observed differences. Participants were recruited in the Clinic for Psychosomatic in Windach and observed during their stationary therapy. The control group was matched for sex, age and educational level. We measured the interoceptive awareness in the beginning (first or second week), in the middle (fifths or sixths week) and at the end (between eighths and tenths week) of the therapy. The protocol for the control group was in line with this procedure. Results: We found significantly reduced interoceptive awareness in the group of OCD patients compared to the controls. OCD patient showed poorer ability of heartbeat detection at every data collection time. Additionally there was no effect over time for the interoceptive awareness, both groups did not differ in their interoceptive awareness compared between the outcome of the heartbeat perception of the first, second and third investigation. The effects remained significant while controlling for anxiety and depression. Correlations between obsessive-compulsive symptoms, measured with the YBOCS, and the heartbeat detection was significant for the first data collection time. At the second and third data collection time no significant correlation between heartbeat detection and obsessive-compulsive symptoms could be found. Discussion Our results are the first to show that OCD patients have difficulties in detecting their bodily signals measured via the heartbeat detection task, an effect that remains significant even when controlling for anxiety and depression. Furthermore we found that the interoceptive awareness of the OCD patients did not improve over the time of therapy. These findings might be useful as prognostic information concerning etiology and maintenance of the disorder. In the context of therapy concepts of the OCD further studies should focus on the impact of the ability of detecting bodily signals. A next step could be to create therapy concepts that include a heartbeat detecting training, maybe combined with techniques of biofeedback to support the development of a healthier homeostatic regulation. ement, the interrelation between different levels of physical activity (low, medium, high) in school and in leisure time as well as interoceptive processes was taken into account. Discussion and Conclusion In conclusion, our results highlight the importance of interoceptive awareness among children and adolescents in terms of self- regulation of behavior.
