Posttraumatic obsessive-compulsive disorder: a three-factor model

This paper presents a three-factor causal model of obsessive-compulsive disorder (OCD), which posits that exposure to long-term traumatic stress generates an inordinate degree of anxiety during the psychological development of the premorbid OCD child. In response to these conditions the child evolves a distinct cognitive style characterized by exaggerated threat appraisal and magical beliefs, and experiences alterations in brain metabolism. An entire functional brain system (a basal ganglia-orbitofrontal circuit) enters into a state of enhanced responsiveness following exposure to protracted threat. Over time the threshold for stimulation is dramatically lowered, resulting in a hypersensitivity to cues that signify potential harm. Individuals adapt to this hypersensitivity through a variety of strategies, which constitute OCD.