Obsessive-compulsive (OC) symptoms have been observed in many schizophrenia patients. Different etiopathological origins of OC symptoms make this type of schizophrenia to be a heterogeneous entity in phenomenological as well as in therapeutic aspects. The complex nature of the treatment response in this group of schizophrenia patients is unclear.

We present a large case series study describes our experience with clozapine, risperidone, olanzapine, quetiapine, ziprazidone, amisulpiride, sertindole and paliperidone as a sole agents and in combination with different serotonin reuptake inhibitors (SRIs) in patients with OCD-schizophrenia (n = 59) and schizo-obsessive disorder (n = 68).

In patients with OCD-schizophrenia treatment with atypicals (other than clozapine), the better results (significant reduction of OC as well as schizophrenia symptoms) were achieved in combination with SRIs, while the olanzapine showed the fastest overall improvement. In schizo-obsessive patients, treatment with atypicals (including clozapine) as monotherapy was the better therapeutic modality, and the risperidone showed the best results. Quetiapine, amisulpiride, sertindole, paliperidone and ziprazidone (as sole agents and with SRIs) were shown as approximately equal in their antipsychotic and antiobsessive activity and overall safety/tolerability.

The effects of different atypicals (with or without SRIs) on psychotic and OC symptoms are vary, probably due to different origin of OC symptoms. We suggest that:

1. 1) schizo-obsessive patients might be successfully treated with atypicals alone;

2. 2) in OCD-schizophrenia atypicals monotherapy may be less efficient, and in some cases even may worsen OC symptoms, so it should be treated concomitantly with SRIs. Further investigations are needed to substantiate our observations.