The following are some common obsessions: fear of dirt or germs, disgust with bodily waste or fluids, concern with order, balance and exactness, worry that a task has been done poorly, fear of thinking evil or sinful thoughts, thinking about certain sounds, images, words or numbers all the time, need for constant reassurance, fear of harming a family member or friend
Some common compulsions are: cleaning and grooming, such as washing hands, showering or brushing teeth over and over again, checking drawers, door locks and appliances to be sure they are shut, locked or turned off, repeating, such as going in and out of a door, sitting down and getting up from a chair, or touching certain objects several times, ordering and arranging items in certain ways, counting over and over to a certain number, saving newspapers, mail or containers when they are no longer needed, seeking constant reassurance and approval. .
For many years, OCD was thought to be rare. The actual number of people with OCD was hidden, because people would hide their problem to avoid embarrassment. Some recent studies show that as many as three million Americans ages 18 to 54 may have OCD at any one time. This is about 2.3% of the people in this age group. No one has found a single, proven cause for OCD. Some research shows that it may have to do with chemical messengers in the brain that carry messages from one nerve cell to another. One of these messengers, called serotonin, helps to keep people from repeating the same behaviors over and over again. A person with OCD may not have enough serotonin. Many people with OCD can function better when they take medicines that increase the amount of serotonin in their brain. It is sometimes accompanied by depression, eating disorders, substance abuse disorder, a personality disorder, attention deficit disorder, or another of the anxiety disorders. Co-existing disorders can make OCD more difficult both to diagnose and to treat.