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

<b><i>Objectives:</i></b> 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. <b><i>Methods:</i></b> 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. <b><i>Results:</i></b> 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). <b><i>Conclusion:</i></b> 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.