Although there is no cure, schizophrenia is highly treatable disease. Successful first episode schizophrenia (FES) treatment is crucial to minimize personal, vocational and social deterioration. Quetiapine is atypical, second generation antipsychotic, serotonin-dopamine antagonist. Quetiapine is potent blocker of D2, 5HT2A and 5HT1A receptors.

To estimate efficacy of quetiapine in treatment of first episode schizophrenia.

This study included 70 patients with FES diagnosed by ICD-10 criteria, who are divided into haloperidol (H) 35 patients and quetiapine (Q) group 35 patients. Patients were observed for 6 months in hospital and extra hospital conditions, according to protocol which included Positive and Negative Symptom Schedule Scale (PANSS) and the number of withdrawals attributed to adverse event (AE). Control group was treated with haloperidol 5–20 mg/24 h and experimental group was treated with quetiapine 400–800 mg/24 h.

Average pretrial PANSS score was 110.1 in quetiapine and 108.5 in haloperidol group. Average PANSS score after 180 days was 50.6 in Q and 60.4 in H group. There is no statistical difference in pretrial scores between groups for PANSS score (P = 0.647). There is significant statistical difference in PANSS score reduction after 180 days in both groups (P < 0.001). There is significant statistical difference in PANSS score reduction between Q and H group after 180 days (P < 0.001). Overall, 8.6% AEs occurred in Q, and 25.8% in H group.

Quetiapine has shown better efficacy in treatment of FES comparing to haloperidol, with statistically significant lower adverse effects rate.

The authors have not supplied their declaration of competing interest.