Exposure and ritual prevention (ERP) has been found to be very effective for treating obsessive-compulsive disorder (OCD) over the last 35 years. We know that as many as 85% of people with OCD can be helped by using ERP. However, many OCD sufferers and their families are confused by some of the terminology associated with this technique. One very important term that confuses many is “habituation”. My goal in this brief article is to help clarify what this term means.