Familial risk of psychosis in obsessive-compulsive disorder: Impact on clinical characteristics, comorbidity and treatment response

Background: Family studies in obsessive-compulsive disorder (OCD) indicate higher rates of psychosis among their first-degree relatives (FDRs). However, the etiological and clinical relationships between the two disorders remain unclear. We compared the clinical characteristics & pharmacological treatment response in OCD patients with a family history of psychosis (OCD-FHP), with a family history of OCD (OCD-FHO) and those with sporadic (OCD-S). Methods: A total of 226 patients who met DSM-IV criteria for OCD (OCD-FHP=59, OCD-FHO=112, OCD-S=55) were included for analysis. All patients were evaluated using the Mini International Neuropsychiatric Interview (MINI 6.0.0), Yale-Brown Obsessive-Compulsive Scale (YBOCS), and the Family Interview for Genetic Studies (FIGS). Treatment response was characterized over naturalistic follow-up. Results: The three groups did not differ across any demographic or clinical variables other than treatment response. Patients in the OCD-FHP risk were found to have received a greater number of trials with serotonin reuptake inhibitors (SRI) (p<0.001) and were more likely to have failed [≥] 2 trials of SRIs. Conclusions: We observed that having a relative with psychosis may predispose to treatment resistance in OCD. Further research on the influence of genetic liability to psychosis on treatment response in OCD may offer novel translational leads.