2.2. Inclusion and exclusion criteria
Exclusion criteria for all participants were as follows: use of drugs affecting the immune system in the last 6 months; any immunological, hematological, neurological, metabolical, or significant medical or infectious disease in the last month; substance abuse in the last 3 months; and smoking.
Inclusion criteria for the patient group were as follows: diagnosed with active OCD according to DSM-5; and persistence of an OCD episode for at least 6 weeks.
Patients who had used psychotropic medications in the last 6 weeks and those who were diagnosed with a comorbid psychiatric disorder were excluded from the study.
The exclusion criteria for the healthy control group were a history of psychiatric disorder and psychotropic drug use.
During the research period, 69 children diagnosed with OCD and 41 healthy children were admitted to the study. In the OCD group, 14 subjects were excluded due to psychiatric comorbidities, 13 due to psychotropic medication use and psychiatric comorbidities, 8 because of non-psychotropic medication use, 3 due to smoking, and 2 because of chronic diseases. In the healthy group, 5 children were excluded because of non-psychotropic medication use, 4 due to a history of psychiatric disorders, 2 because of smoking, and 2 due to a newly diagnosed psychiatric disorder. Thus, 29 children with OCD and 28 healthy controls met the inclusion and exclusion criteria and were included in the research.