Additional Study Information: The goal of the project is to identify brain signatures associated with obsessive-compulsive disorder (OCD) by comparing brain images of (1) individuals with OCD, (2) individuals without OCD, and (3) siblings of individuals with OCD. Eligible participants will be asked about their medical and psychiatric history, perform tasks on a computer, and receive a brain scan using Magnetic Resonance Imaging (MRI). The study requires one in-person visit and one assessment by telehealth. Participants will be compensated for their time and effort and may also be eligible for treatment (delivered via telehealth) at no cost with one of our OCD specialists.