Predictors of clozapine efficacy in treatment-resistant schizophrenia: A cross-sectional analysis of sociodemographic, clinical, biochemical, and electrophysiological EEG changes

Abstract

Abstract Context: Although neuroleptics are available for treating schizophrenia, patient compliance with treatment remains a major hurdle. Such patients turn into treatment-resistant schizophrenia (TRS) where clozapine can be prescribed, but it causes severe side effects. Many markers can predict favorable responses to clozapine therapy. Aims: To assess sociodemographic, clinical, electrophysiological, and biochemical parameters among TRS patients and to evaluate the difference between TRS patients with and without response to clozapine. Settings and Design: A prospective observational study was carried out for a period of 2 years from October 31, 2020, to November 1, 2022, in the Psychiatry Department of a Tertiary Care Hospital in Eastern Odisha. Materials and Methods: All patients visiting the Psychiatry Department of a tertiary care hospital, diagnosed with International Classification of Diseases schizophrenia were screened for TRS as per modified Kane’s criteria. The assessed parameters were compared using the Brief Psychiatry Rating Scale, the Positive and Negative Syndrome Scale of Schizophrenia, and Clinical Global Impressions scale. Statistical Analysis Used: Data were compiled and analyzed using IBM corporation’s Statistical Package for the Social Sciences (SPSS) software version 27. Results: Thirty-one eligible patients consented to the study, with 21 (67.7%) females and 10 (32.3%) males. Maximum, 17 (54.8%), belonged to 18–35 years of age. The biochemical parameters, fasting blood sugar (FBS), and triglycerides (TGs) had mean values of 94.56 (±6.6) mg/dL and 157 (±9.8) mg/dL, respectively. Gross electroencephalogram abnormalities were seen in 3 (10%) cases. Conclusions: The female gender, higher education, and a shorter duration of untreated psychosis predicted a better outcome. The patients showing good responses had higher trends in FBS and TGs at follow-up. Clozapine was associated with increased electrophysiological intra- and interhemispheric asymmetry.