Comparison of Clinical Characteristics Between the Patients with Schizophrenia on Clozapine Treatment with Those Taking Combination of Long-Acting Injectable and Oral Antipsychotics.

INTRODUCTION: The primary aim of this study was to compare clinical characteristics between the patients with schizophrenia on clozapine treatment with those under combination of long-acting injectable and oral antipsychotics (combined treatment), and the secondary aim was to evaluate the impact of obsessive-compulsive disorder (OCD) comorbidity on the clinical variables.
METHODS: The patients with schizophrenia applied at Outpatient Psychiatry Clinic of the University between October 2017 and March 2018 taking clozapine or combined treatment were included in the study. The participants were administered Brief Psychiatric Rating Scale (BPRS), Clinical Global Impressions Scale, Scale for the Assessment of Positive and Negative Symptoms (SAPS/SANS), Calgary Depression Scale for Schizophrenia (CDSS), Yale-Brown Obsessive Compulsive Scale (YBOCS), Turkish version of Schedule for Assessing the three components of insight (SAI), and Global Assessment of Functioning Scale (GAF).
RESULTS: Patients on clozapine had higher Y-BOCS, BPRS, SANS, CDSS scores, and lower GAF scores compared to those taking combined antipsychotics (p<0.05). OCD comorbidity rate was 13% in the combination therapy group and 36% in clozapine users. The SAPS scores were higher but CDSS scores were lower in clozapine users with the presence of OCD comorbidity (p<0.05).
CONCLUSION: Clozapine and combined therapy groups differed widely by the clinical characteristics of the patients in this study. Both groups showed a high OCD comorbidity rate in this study and OCD comorbidity should be considered when schizophrenia treatment is initiated to obtain more satisfactory results. Furthermore, patients on clozapine seem to show a different relationship with OCD comorbidity compared to those under combined treatment.