Background Obsessive-compulsive disorder (OCD) is a psychiatric condition that typically
manifests in compulsive urges to perform irrational or excessive avoidance behaviors. A
recent account has suggested that compulsivity in OCD might arise from excessive stimulus-
response habit formation, rendering behavior insensitive to goal value. We tested if OCD
patients have a bias toward habits using a novel shock avoidance task. To explore how
habits, as a putative model of compulsivity, might relate to obsessions and anxiety, we …