Preferential aggregation of obsessive-compulsive spectrum disorders in schizophrenia patients with obsessive-compulsive disorder.

OBJECTIVE: To validate a complex association between schizophrenia and obsessive-compulsive disorder (OCD). METHOD: We used the Structured Clinical Interview for DSM-IV Axis I disorders to compare the rate of OCD spectrum and additional Axis I disorders in 100 patients who met criteria for both schizophrenia and OCD, non-OCD schizophrenia (n = 100), and OCD (n = 35). RESULTS: There was a robust between-group difference in the number of patients with one or more OCD spectrum disorders (schizo-obsessive n = 30, compared with schizophrenia n = 8; P = 0.001), that is, higher rates of body dysmorphic (8% compared with 0%) and tic (16% compared with 4%) disorders. No difference was revealed in affective, anxiety, and substance use disorders. We found comparable rates of OCD spectrum disorders in the schizo-obsessive and OCD groups (30% and 42.8%, respectively; P = 0.32). CONCLUSION: Preferential aggregation of OCD spectrum disorders in the schizo-obsessive group supports this unique clinical association. Whether a schizo-obsessive interface represents comorbidity or a specific subtype of schizophrenia warrants further investigation.

Familial aggregation of schizophrenia-spectrum disorders and obsessive-compulsive associated disorders in schizophrenia probands with and without OCD.

A substantial proportion of schizophrenia patients also has obsessive-compulsive disorder (OCD). To further validate the clinical validity of a schizo-obsessive diagnostic entity, we assessed morbid risks for schizophrenia-spectrum disorders and OC-associated disorders in first-degree relatives of schizophrenia probands with and without OCD. Two groups of schizophrenia probands [with OCD (n = 57) and without OCD (n = 60)] and community-based controls (n = 50) were recruited. One hundred eighty two first-degree relatives of probands with OCD-schizophrenia, 210 relatives of non-OCD schizophrenia probands, and 165 relatives of community subjects were interviewed directly [59.3% (108/182), 51.9% (109/210), and 54.5% (90/165), respectively], using the Structured Clinical Interview for Axis-I DSM-IV Disorders and Axis II DSM-III-R Personality Disorders and the remaining relatives were interviewed indirectly, using the Family History Research Diagnostic Criteria. Relatives of OCD-schizophrenia probands had significantly higher morbid risks for OCD-schizophrenia (2.2% vs. 0%; P = 0.033) and OCPD (7.14% vs. 1.90%; P = 0.014), and a trend towards higher morbid risk for OCD (4.41% vs. 1.43%; P = 0.08) compared to relatives of non-OCD schizophrenia probands. When morbid risks for OCD, OCPD, and OCD-schizophrenia were pooled together, the significant between-group difference became robust (13.74% vs. 3.33%; P = 0.0002). In contrast, relatives of the two schizophrenia groups did not differ significantly in morbid risks for schizophrenia-spectrum disorders, mood disorders, or substance abuse disorders. A differential aggregation of OC-associated disorders in relatives of OCD-schizophrenia versus non-OCD schizophrenia probands, provides further support for the validity of a putative OCD-schizophrenia ("schizo-obsessive") diagnostic entity.

Comparison of clinical characteristics and comorbidity in schizophrenia patients with and without obsessive-compulsive disorder: schizophrenic and OC symptoms in schizophrenia.

BACKGROUND: Since a substantial proportion of schizophrenia patients has symptoms of obsessive-compulsive disorder (OCD), we sought to provide a phenomenological characterization of a schizophrenia subgroup with OCD. METHOD: A consecutive sample of patients who met DSM-IV criteria for both schizophrenia and OCD (N = 55) was compared with 55 schizophrenia patients without OCD matched for age and number of hospitalizations. Structured Clinical Interview for DSM-IV Axis I psychiatric disorders (SCID-I), including a specific module for tic disorders based on DSM-IV criteria, Scales for the Assessment of Positive and Negative Symptoms, Yale-Brown Obsessive-Compulsive Scale, Clinical Global Impressions scale, and Hamilton Rating Scale for Depression were used. RESULTS: Schizophrenia patients with OCD (N = 55) had lower positive dimension scores than schizophrenia patients without OCD (N = 55) (p =.01). Two subgroups of schizo-obsessive patients were identified: OCD independent of schizophrenia symptoms and OCD partially overlapping positive schizophrenia symptoms. Schizophrenia patients with OCD had more SCID-detectable OCD-spectrum disorder, primarily body dysmorphic disorder and chronic tic disorders. More schizophrenia patients with OCD were treated with either add-on serotonin reuptake inhibitors or clozapine. CONCLUSION: Schizophrenia patients with OCD differ from their non-OCD-schizophrenia counterparts in severity of schizophrenia symptoms, co-occurrence of OCD-spectrum disorders, and pharmacotherapy. These findings and the identification of 2 subgroups of schizo-obsessive patients support the validity of this unique clinical entity and may facilitate the establishment of diagnostic criteria for a schizo-obsessive subtype of schizophrenia.