# Efficacy and influencing factors of modified electroconvulsive therapy for schizophrenia: a real-world retrospective observational study

## TL;DR

This study finds that modified electroconvulsive therapy (MECT) is more effective for younger, first-time schizophrenia patients with severe symptoms, but less so for older patients with long illness duration.

## Contribution

Identifies specific clinical and electrophysiological predictors of MECT efficacy in schizophrenia patients.

## Key findings

- MECT effectiveness rate was 70.46% in schizophrenia patients.
- Younger age, first-episode status, and higher baseline positive symptoms predicted better MECT response.
- Older patients and those with longer illness duration had poorer treatment outcomes.

## Abstract

Schizophrenia (SCZ) is a chronic and disabling psychiatric disorder. Modified Electroconvulsive Therapy (MECT), which involves electrical stimulation under general anaesthesia and muscle relaxation, is widely used to treat SCZ. Despite its rapid onset and robust therapeutic effect, the efficacy of MECT varies significantly between individuals. This study aimed to evaluate the clinical effectiveness of MECT in patients with SCZ and identify its influencing factors, with the goal of informing personalised treatment strategies.

This retrospective observational study included 237 inpatients with SCZ who received a full course of MECT at the Fourth People’s Hospital of Nantong between January 2023 and December 2024. Treatment response was evaluated using the Positive and Negative Syndrome Scale (PANSS) reduction rate. Patients were classified into effective (≥50% reduction) and ineffective (<50% reduction) groups. Demographic, clinical, and treatment-related variables were compared between groups, and multivariate logistic regression was used to identify predictors of treatment response.

The overall effectiveness rate of MECT was 70.46%. Multivariate analysis identified age ≥50 years (OR = 0.111–0.078, P = 0.010–0.002) and illness duration ≥10 years (OR = 0.028–0.003, P < 0.05) as negative predictors of response. In contrast, first-episode SCZ (OR=6.537, P = 0.003), higher baseline positive symptom scores (OR = 1.325, P<0.001), and longer EEG seizure duration (OR = 1.183, P<0.001) were positive predictors. No significant associations were found for sex, education level, or stimulus parameters such as current or frequency.

MECT remains a clinically valuable intervention for SCZ, particularly in younger, first-episode patients with prominent positive symptoms. Treatment efficacy is influenced by age, illness duration, baseline symptom severity, and seizure quality. These findings support the need for personalised MECT protocols guided by clinical and electrophysiological characteristics.