3. Follow-up study: After finishing the 12-week treatment, the OCD patients will be into a 6-month follow-up. Patients who are satisfied with pharmacological and/or psychological treatment will continue the current treatment, while others' follow-up treatment and specific treatment ways will be decided by researchers through the results of of our randomized controlled study. Our randomized controlled study results will be divided into valid and invalid groups. To the invalid psychological or pharmacological treatment group, patients will have a 12-week combined treatment which means invalid pharmacological treatment need to combine with psychological treatment and invalid psychological treatment need to combine with pharmacological treatment. Invalid pharmacological combined with psychological treatment should adjust the medicine (change with sertraline/fluvoxamine) and go on the psychological treatment. After the baseline assessment, OCD patients will have a follow-up evaluation at the 16th, 24th, and 36th week, while the healthy control will have a follow-up evaluation at the 12th and 36th week.