Obsessive–compulsive disorder comorbid with schizophrenia and bipolar disorder

Obsessive Compulsive Disorder (OCD) and Obsessive Compulsive Symptoms (OCS) are known to be highly comorbid with bipolar disorder and schizophrenia. Comorbid OCD/OCS influences the course of schizophrenia and bipolar disorder. There is also some evidence to suggest that a diagnosis of OCD may be associated with elevated risk for later development of psychosis and bipolar disorder. Comorbid OCD/OCS is associated with a greater severity of schizophrenia phenotype and poorer prognosis. In addition, certain atypical antipsychotics, clozapine in particular are known to induce or worsen OCS in schizophrenia. OCD when comorbid with bipolar disorder mostly runs an episodic course with worsening and improvement of OCD/OCS in depressive and in manic/hypomanic phases respectively. There is limited systematic data on the treatment of OCD in schizophrenia and bipolar disorder. When OCD presents in the context of schizophrenia, management may include treatment with atypical antipsychotics with limited serotonergic properties, changing the antipsychotic, reduction in the dose of the antipsychotic, addition of cognitive-behavior therapy (CBT), or a specific serotonin reuptake inhibitor (SSRI). When OCD is comorbid with bipolar disorder, mood stabilization is the priority. CBT may be preferred over SSRIs to treat OCD/OCS that persist in between the mood episodes because SSRIs may induce a switch or worsen the course of bipolar disorder. SSRIs when indicated have to be used judiciously under the cover of adequate mood stabilization.