Clinical and neuroradiological differences in obsessive compulsive disorder with and without psychosis

Obsessive-compulsive disorder (OCD) and psychosis frequently co-occur, with several hypotheses proposed to explain the relationship between them, and there is limited information regarding the comorbidity of OCD and psychotic symptoms. Therefore, we aimed to detect the prevalence of psychotic symptoms in OCD patients and analyze the psychopathological and neuroimaging associations using Diffuse Tensor Imaging (DTI) between OCD with and without psychotic symptoms in a subset of these patients. Initially, 100 subjects with OCD were assessed using the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I), Yale-Brown Obsessive Compulsive Scale (Y-BOCS), Positive and Negative Syndrome Scale (PANSS) and Brief Psychiatric Rating Scale (BPRS) and a subset of 60 subjects underwent neuroimaging using DTI. Out of 100 subjects, 39 % were classified as OCD with psychotic features, who differed significantly from non-psychotic OCD on several Y-BOCS, BPRS and DTI (especially volume) domains. Our study suggests several clinical and neuroradiological (using DTI) differences between OCD with and without psychotic features. Clinically, the OCD group with psychotic symptoms had a shorter duration of illness, fewer previous episodes and a poorer level of insight, while on DTI, they had significant reduction in grey matter (GM) volume across several brain regions, and significant reduction in the right hippocampal tract on mean diffusivity (MD).