Psychopathology and quality of life among patients with comorbidity between schizophrenia spectrum disorder and obsessive-compulsive disorder: No evidence for a "schizo-obsessive" subtype

Background Epidemiological studies have found that obsessive-compulsive disorder (OCD) is estimated to occur in up to 12% of patients with schizophrenia. Furthermore, several etiopathogenic mechanisms have been postulated for understanding this co-occurrence. Whether this subgroup of "schizo-obsessive" patients may be posed as a clinical entity with a distinct psychopathological and functioning profile remains unclear. Method A sample of adult patients who met DSM-IV criteria for both schizophrenia/ schizoaffective disorder and OCD (n = 30) was compared with a "non-OCD schizophrenic" group (n = 37) and another subset of "non-schizophrenic OCD" patients (n = 30). The Positive and Negative Syndrome Scale (PANSS), the Scale to Assess Unawareness of Mental Disorder (SUMD), the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), the Brown Assessment of Beliefs Scale (BABS), the Clinical Global Severity scale (CGI), the Quality of Life Scale (QLS), and the Beck's Depression Inventory (BDI) were used. Results We found that "schizo-obsessive" subjects did not show significant differences in any outcome measures when compared to the "non-OCD schizophrenic" group. Furthermore, statistical analyses also revealed that the "non-schizophrenic OCD" group tended to have lower severity of psychopathology as well as greater quality of life than both psychotic groups. Conclusions These findings indicate that comorbidity between schizophrenia/schizoaffective disorder and OCD does not comprise a distinct clinical entity, particularly when compared to "non-OCD schizophrenia" disorder. Discrepancies among previous studies may be justified by methodological divergences.