What Is OCD? Obsessive-Compulsive Disorder (OCD) is a mental health condition that involves recurring, intrusive thoughts (obsessions) and repetitive behaviors or mental rituals (compulsions). These patterns can feel difficult to control and may take up a significant amount of time, often interfering with daily life, relationships, and overall well-being. OCD can begin at different stages of life, including childhood, adolescence, or adulthood. How Common Is OCD? OCD affects