Schizophrenia could be presented with obsessive thoughts or an obsessive-compulsive disorder. It is known that some antipsychotics like clozapine could cause obsessive symptoms or worsen them.

We report the case of a 53-year-old male who was diagnosed of schizophrenia. The patient was admitted into a long-stay psychiatric unit due to the impossibility of outpatient treatment. He presented a chronic psychosis consisted in delusions of reference, grandiose religious delusions, and auditory pseudohallucinations. He often presented behavioral disturbances consisted in auto and heteroaggressive behavior, being needed the physical restraint. Various treatments were used, including clozapine, but obsessive and ruminative thoughts went worse. Because of that, clozapine dose was lowed, and it was prescribed sertraline and clomipramine. With this treatment the patient presented a considerable improvement of his symptoms, ceasing the auto and heteroaggressive behavior, presenting a better mood state, and being possible the coexistence with other patients. Psychotic symptoms did not disappeared, but the emotional and behavioral impact caused by them was lower.

This case report shows how a patient with schizophrenia could present severe behavioral disturbances due to obsessive symptoms. If obsessive symptoms are presented, clozapine must be at the minimum effective dose and antidepressants with a good antiobsessive profile.

Obsessive symptoms could be presented as a part of schizophrenia. Clozapine could worsen this symptoms and it is necessary to adjust its dose to the minimum effective dose.

The authors have not supplied their declaration of competing interest.