Obsessive-Compulsive Disorder is a mental disorder classified as an anxiety disorder. People with anxiety disorders experience fears even when there is no concrete experience that might cause them to be afraid. The type of anxiety that people with OCD experience is persistent intrusive thoughts (obsessions) or behaviors (compulsions). People with OCD feel compelled to continue despite an awareness that the thoughts or behaviors may be excessive or inappropriate, and feel distress if they stop doing them.