The 5-year course of OCS/OCD in patients with first-episode schizophrenia or related disorders is variable. OCS/OCD comorbidity was not associated with a more severe course of psychotic symptoms and relapse. Comorbid OCD was associated with more severe depressive symptoms, social dysfunction and worse premorbid functioning. Specific treatment options for schizophrenia patients with comorbid OCD are needed.

Specific interventions are needed focusing on patients living in highly urbanized areas and first generation immigrants in order to shorten patient delay. MHS should improve early detection of psychosis in patients already in treatment for other diagnosis.

These results support the clinical relevance of OCS co-morbidity in schizophrenia or related disorders and the need for research into specific interventions.