OBSESSIVE-COMPULSIVE DISORDER AMONG SCHIZOPHRENIC-PATIENTS - AN EXPLORATORY-STUDY USING FUNCTIONAL MAGNETIC-RESONANCE-IMAGING DATA

Despite the growing research on the etiology of obsessive-compulsive d isorder (OCD), and schizophrenia, the clinical distinction between the two disorders is not clearly understood. In the present investigation , we sought to better understand the relationship between OCD and psyc hotic disorders by examining functional magnetic resonance imaging (fM RI) data from a group of schizophrenic patients with varying degrees o f OCD symptomatology, based on results of the Yale-Brown Obsessive Com pulsive Scale (Y-BOCS) and the National Institute of Mental Health (NI MH) rating scales of OCD. While subjects performed a cognitive challen ge paradigm that included a verbal fluency task, activation data from the left dorsolateral prefrontal cortex were collected and analyzed. W e hypothesized that the fMRI signal patterns in schizophrenic patients with high levels of OCD symptomatology would differ from that of schi zophrenic patients with a low level of OCD. For the group as a whole, no significant relationship was found for scores of either rating scal e and fMRI signal change; however, a significant association was found for a subgroup of patients. For these schizophrenics, there was a neg ative relationship between OCD symptomatology and activation of the le ft dorsolateral prefrontal cortex. These results support the suggestio n of several researchers that a relationship between OCD severity and neurophysiological activity exists in schizophrenia. Copyright (C) 199 8 by W.B. Saunders Company.