When intrusive thoughts occur with obsessive-compulsive disorder (OCD), patients are less able to ignore the unpleasant thoughts and may pay undue attention to them, causing the thoughts to become more frequent and distressing. The suppression of intrusive thoughts often cause these thoughts to become more intense and persistent. The thoughts may become obsessions that are paralyzing, severe, and constantly present, these might involve such topics such as thoughts of violence, sex, or religious blasphemy to name a few examples. Distinguishing them from normal intrusive thoughts experienced by many people, the intrusive thoughts associated with OCD may be anxiety provoking, irrepressible, and persistent.