Enhanced Avoidance habits in obsessive-compulsive disorderGillan, Morein-Zamir, Urcelay, Sule, Voon, Apergis-Schoute, Fineberg, Sahakian, & Robbins (2014)Biological psychiatry Obsessive compulsive disorder (OCD) is a psychiatric condition that typically manifests in compulsive urges to perform irrational or excessive behaviours. OCD patients have a tendency to develop excessive avoidance habits. Most patients with OCD recognize that their concerns are unrealistic and that their behaviour is absurd or at least excessive.OCD patients have a bias toward appetitive habit formation at the expense of goal-directed behaviour, an imbalance that might contribute to the repetitive and seemingly senseless compulsions that exemplify the disorder. The compulsions in OCD are avoidant rather than appetitive.One of the longest standing accounts of OCD symptomatology is that compulsions are not habits but rather are rational avoidance responses triggered by irrational beliefs. Irrational beliefs are considered the product of cognitive bias in OCD. These beliefs are thought by some to form the basis of obsession, and, in turn, anxiety in OCD, to which compulsions are a goal-directed avoidance response.Excessive behavioural repetition in OCD might be driven by a failure to learn about safety.Conditioned fear and anxiety are also thought to be important for OCD, and can bias healthy individuals to behave habitually. OCD patients have a bias toward developing...