Primarily Obsessional Obsessive-Compulsive Disorder (also called Purely Obsessional OCD) is a lesser-known form of obsessive-compulsive disorder (OCD). For people with primarily obsessional OCD, there are less easy-to-see compulsions, compared to the compulsions that people with regular OCD have (like checking, counting, hand-washing). While people with Primarily Obsessional OCD may do rituals, they mostly take place in their mind. Primarily obsessional OCD often takes the form of horrific thoughts that pop into the person's head. These thoughts may be scary or violent.