**9. Conclusion**

OCD is an important psychiatric disorder in childhood and adolescence. At this age OCD is common, but the diagnosis is often missed. For this reason OCD usually shows chronic progress and serious loss of function. OCD could be confused with other diseases, or comorbidities could be seen. These conditions make it difficult to treat the disease. Although the disease has not completely recovered by the treatment, symptoms can be improved, or functionality may improve somewhat.

OCD could not be as well-defined as adults. Therefore more clinical studies are needed. These studies lead to a better understanding for etiology, treatment, and course of OCD. With the new treatment approaches, OCD could be treated at early age period, and chronicity could be preventable. Thus the incidence of OCD in adulthood may decrease, and it may increase patients' quality of life.
