Oxytocin and obsessive–compulsive disorder

Attention has recently been focused on central nervous system neuropeptides as potential mediators of the symptom profile of obsessive–compulsive disorder (OCD). OCD includes a range of cognitive and behavioral symptoms that bear some relationship to dimensions of behavior associated with oxytocin (OT). Increased cerebrospinal fluid levels of the anxiolytic neuropeptide OT have been reported in OCD. OT is a neurosecretory nonapeptide synthesized in hypothalamic cells, which project to widely distributed sites in the central nervous system as well as the neurohypophysis. Central OT affects a variety of cognitive, grooming, affiliative, sexual, and reproductive behaviors in animals. OT is associated with the regulation of complex sociocognitive processes such as attachment, social exploration, social recognition, anxiety, and other stress-related behaviors. Based on these data, we hypothesized that OCD is mediated by OT. The aim of this review is to define possible involvements of OT in the pathophysiology of OCD.