Schizophrenia with obsessive-compulsive disorder and obsessive-compulsive disorder with poor insight: a neuropsychological comparison

Schizophrenia patients with obsessive-compulsive disorder (OCD) may be a subgroup of schizophrenia, and OCD patients with poor insight may show psychotic-like symptoms. The aim of this work is to compare the neuropsychological performance of those patients with schizophrenic patients who do not have OCD symptoms and with OCD patients who have good insight. The sample consisted of 89 patients (16 OCD-schizophrenic patients, 30 non-OCD schizophrenic patients, 30 OCD patients with good insight, 13 OCD patients with poor insight). Neuropsychological evaluation included executive functions, verbal and visual memory and attention tasks. While schizophrenic patients with OCD did not differ from the non-OCD schizophrenia and OCD with poor insight groups on long-term visual and verbal memory performance, they showed poorer performance than the OCD group on long-term visual and verbal memory tests. Considering executive function, the OCD group with poor insight performed significantly worse than their counterparts with good insight, and the latter group performed better than the schizophrenia patients. The results of this study suggest that the neuropsychological performance of schizophrenia patients with OCD did not differ from that of non-OCD schizophrenic patients, and that OCD patients with poor insight were more likely to share similar cognitive characteristics with the schizophrenia groups. Our results also provide neuropsychological support for the hypothesis that OCD and schizophrenia may be a spectrum disorders.