Keywords: سیستم سروتونین; Genetics; Obsessive-compulsive disorder; OCD; Serotonin system; Neuropsychiatry; Neuroscience; Psychiatry; Candidate gene; Genetic association; Serotonin transporter; SLC6A4; 5-HTTLPR; HTR2A; 5-HT2A; HTR1B; 5-HT1B; HTR2C; 5-HT2C; Subtypes; Symptom dimensi