Soft Neurological Signs in Drug-Free People With Schizophrenia With and Without Obsessive-Compulsive Symptoms

Abstract

Obsessive-compulsive (OC) symptoms are clinically important phenomena in people with schizophrenia. Schizophrenia and obsessive-compulsive disorder (OCD) are considered as neurodevelopmental disorders with dysfunctional frontal subcortical circuitry. In this cross-sectional study, the authors tested the hypothesis that people with schizophrenia with OC symptoms form a subtype with a distinct neurological substrate. Using the Neurological Evaluation Scale (NES), the authors assessed 65 people with ICD-10 criteria for schizophrenia, 21 of whom had OC symptoms, and who were drug-naive or had not received any antipsychotic or anti-obsessive drugs for the previous 3 months. People with schizophrenia and OC symptoms were better educated than those without OC symptoms and differed significantly in proportion to premorbid OC symptoms, but did not differ on measures of psychopathology. Total NES scores and subgroup scores did not differ significantly between people with schizophrenia with or without OC symptoms, but the groups did differ in motor coordination test scores for the left side. Total NES scores correlated significantly with Positive and Negative Symptom Scales negative symptoms scores in those with OC symptoms but not in those without OC symptoms; this correlation was not observed with Yale-Brown Obsessive-Compulsive Scale scores. These findings, if replicated, suggest that OC symptoms in people with schizophrenia are due to differences in frontocerebellar neurological circuitry from those without OC symptoms, with possible neuro-developmental origins.