Supplementary Material for: Augmentation of Antipsychotics with Electroconvulsive Therapy in Treatment-Resistant Schizophrenia Patients with Dominant Negative Symptoms: A Pilot Study of Effectiveness

Objectives: The aim of the study was to determine the effectiveness of the augmentation of antipsychotics (AP) with electroconvulsive therapy (ECT) in treatment-resistant schizophrenia (TRS) patients with dominant negative symptoms. Methods: The study encompassed 34 patients aged 21-55 years, 47.1% of whom were female, who were diagnosed with TRS. Each patient underwent a course of ECT sessions combined with AP medications which had previously been found to be ineffective. Prior to ECT and within 3 days after the final ECT session, the participants were evaluated on the Positive and Negative Syndrome Scale (PANSS), the Calgary Depression Scale for Schizophrenia and the Clinical Global Impression scales. Results: Augmentation of AP therapy with ECT led to a significant decrease in symptom severity in TRS patients with dominant negative symptoms, 58.8% of whom demonstrated at least a 25% decrease in the total PANSS score. The greatest reductions were observed in the general and positive PANSS subscales (mean ± SD: 11.35 ± 7.43 and 6.79 ± 5.23 patients), and the least significant in the negative symptoms subscale (5.03 ± 4.36 patients). Conclusion: Augmentation of AP therapy with ECT in a group of TRS patients with dominant negative symptoms induced a significant decrease in symptom severity. The greatest reductions were obtained in general and positive symptoms and the least in negative symptoms.