Psychiatry Research EG

Background Obsessive–compulsive symptoms (OCS) have been frequently described in schizophrenic populations. There is a controversy on whether this co-occurrence is more than just comorbidity or represents a distinct subgroup in schizophrenia. Aim The aim of this study was to investigate whether there are possible underlying structural and functional differences between schizophrenic patients with and those without OCS. Patients and methods Participants in this study were divided into three groups: 20 patients having schizophrenia with OCS; 20 patients having schizophrenia without OCS (both were diagnosed according to DSM-IV-TR); and 20 matching controls. All participants underwent an MRI for volumetric measurement of the caudate nucleus and a magnetic resonance spectroscopy to measure choline (Cho), creatine, and N-acetyl aspartate (NAA) in the caudate nucleus. Results Caudate volume was found to be reduced in schizophrenic patients with or without OCS (Pr0.05). Magnetic resonance spectroscopy findings showed that schizophrenic patients without OCS had significant increase in Cho concentration (Pr0.05), but average NAA concentration. In contrast, schizophrenic patients with OCS had significant reduction in NAA concentration (Pr0.05) with average Cho concentration. Conclusion Schizophrenic patients with OCS may have an atypical set of neuroradiological characteristics that would specifically categorize it within the schizophrenia spectrum. Keywords: caudate volume, magnetic resonance spectroscopy, obsessive-compulsive symptoms, schizophrenia