This research includes case control study and randomized controlled single-blind study. At baseline, we compare the dimensions of clinical symptoms, genetics and imaging between OCD patients and healthy controls. The OCD patients are randomly assigned into pharmacological treatment, psychological treatment or pharmacological combined with psychological treatment for a 12-week treatment. After a 12-week treatment, the OCD patients will be divided into valid and invalid groups according to the results of our randomized controlled study by researchers: to our valid group, patients will continue the current treatment, and to the invalid psychological or pharmacological treatment group, patients will have a 12-week combined treatment. From the baseline, we will have a 9-month follow up for both OCD patients and healthy controls.