Niels T. de Joode, Chris Vriend, Petra J.W. Pouwels, Feng Liu, Maria Cg Otaduy, Bruno Pastorello, Frances Robertson, Jonathan Ipser, Seonjoo Lee, Anton J.L.M. van Balkom, Dianne M. Hezel, Marcelo C. Batistuzzo, Marcelo Q. Hoexter, Karthik Sheshachala, Janardhanan C. Narayanaswamy, Ganesan Venkatasubramanian, Christine Lochner, Euripedes C. Miguel, YC Janardhan Reddy, Roseli G. Shavitt, Dan J. Stein, Melanie M. Wall, Helen Blair Simpson, Odile A. van den Heuvel
=0.049). No associations were found for illness duration, onset, or medication history. In the largest prospective structural imaging study of unmedicated OCD to date, we found no significant case-control differences in cortical or subcortical morphology. Instead, structural associations were driven by clinical characteristics, including symptom severity, dimensionality, and comorbidity, supporting neuroanatomical models emphasizing the OFC and insula. The absence of case-control differences underscores the importance of studying large unmedicated samples with careful clinical characterization before concluding brain findings are related to the disorder.