Obsessive-compulsive disorder (OCD) is a common mental health problem. Symptoms typically include recurring obsessive thoughts, and repetitive compulsions in response to the obsession. A common example is recurring obsessive thoughts about germs and dirt, with a compulsion to wash your hands repeatedly to "clean off the germs". However, there are many other examples. The usual treatments are cognitive behaviour therapy, a selective serotonin reuptake inhibitor (SSRI) antidepressant medicine, or both.