Relationship between psychotic and obsessive compulsive symptoms in schizophrenia

The presence of obsessive compulsive symptoms (OCSs) in schizophrenia was recognized as early as the first descriptions of the illness. Studies investigating the association between OCSs and schizophrenia have defined their co-occurrence in terms of co-morbidity and compared schizophrenia patients separated into groups according to whether they presented OCSs or not. However, most of these studies did not take both the complexity of the schizophrenia phenomenology and that of OCSs into account. The present research investigates the relationship between schizophrenia symptoms and OCSs using a correlational approach with a dimensional perspective in order to determine how the OCSs contribute to symptom expression in schizophrenia. Fifty nine schizophrenia patients were rated for schizophrenia symptoms (SAPS-SANS) and OCSs (Y-BOCS). Schizophrenia symptoms scores were collapsed into four dimensional scores and OCSs into for other dimensional scores. The latter were entered as explanatory variables to determine their associations with schizophrenia dimension scores using series of stepwise regression models. The results showed a strong positive relationship between Delusions and Obsessions consistent with the view that they reflect manifestations of the similar mechanisms. Similar results indicate an association between Auditory hallucinations and Compulsions also suggesting that they share common mechanisms. On the other hand, there were inverse relationships between Somatic Obsessions and Disorganization and between Hoarding/Collecting Compulsions and Delusions or Auditory hallucinations. These results may reflect that these OCSs have a protective effect against disorganization and psychotic symptoms respectively.