Efficacy & Tolerability of Rigth Unilateral vs. Bitemporal ECT in Schizophrenia in a Psychiatric Hospital in Mexico

Overview

Electroconvulsive therapy (ECT) is an established treatment for medication-resistant schizophrenia. There is debate about the best method of electrode placement. Bitemporal (BT) placement is commonly used for schizophrenia, while right unilateral (RUL) placement in mood disorders is associated with fewer adverse effects on memory and language. This study compares the efficacy, safety and cognitive effects of BT-ECT versus RUL-ECT in hospitalized schizophrenia patients with acute psychosis. Main Question: Does RUL-ECT reduce psychotic symptoms with fewer cognitive effects versus BT-ECT in patients with severe schizophrenia? Hypothesis: RUL-ECT is as effective as BT-ECT in reducing psychotic symptoms with fewer cognitive effects. Methods: Randomized trial in patients with schizophrenia (confirmed by DSM 5 criteria) and severe symptoms (PANSS score ≥60). Patients were assigned to receive BT-ECT or RUL-ECT. Efficacy was measured by a ≥30% reduction in symptom severity on the PANSS scale and overall improvement measured with the Clinical Global Impression scale. Cognitive function was assessed with the Montreal Cognitive Assessment (MoCA) and Brief Assessment of Cognition in Schizophrenia (BACS) scales.

Study Design and Setting: Randomized experimental trial at Fray Bernardino Álvarez Psychiatric Hospital, Mexico City. Sample Size: Quota sampling. Eligibility Criteria: inpatients, spanish-speaking, ≥18 years old with DSM-5 schizophrenia diagnosis, PANSS total score ≥60, and treatment with 1-2 antipsychotics (including clozapine). Exclusions: ECT within 3 months, affective comorbidities, catatonia, pregnancy, anesthesia/ECT contraindications, or incomplete follow-up. Equipment and Technique: Pre-ECT evaluations included ECG, chest X-ray, blood tests, and assessments by internists/anesthesiologists. ECT was administered by a principal investigator (Emory University-certified) using a MECTA Corp spECTrum 5000Q device, 3x/week (excluding weekends). Electrode placement: bitemporal (BT) with brief pulses (≥0.5 ms) or right unilateral (RUL; D'Elia placement) with ultrabrief pulses (≤0.3 ms). Initial titration doses: 48 mC (BT) or 4.8 mC (RUL), doubled until adequate seizure (assessed via Clinical and Seizure Based Stimulation method). Maintenance doses: 2x threshold (BT) or 6x threshold (RUL), adjusted by 50% for poor-quality seizures. Premedication: atropine (1 mg IM), propofol (1 mg/kg IV), and succinylcholine (1 mg/kg IV). Intervention and Comparator: Active comparator: BT-ECT vs. RUL-ECT.(intervention) No placebo group due to institutional constraints. Randomization and Blinding: Block randomization (Microsoft Excel-generated) by an independent researcher. Allocation sequence concealed by an assistant and disclosed pre-treatment. Outcomes: Efficacy: ≥30% PANSS reduction; Safety: Adverse event frequency/severity/time to adverse event onset. Cognition: MoCA and BACS pre-/post-ECT (administered by neuropsychology-trained staff). Ethics: Conducted per WMA Declaration of Helsinki. Informed consent obtained from patients' legal guardians due to severe mental impairment in participants