# Differences in electrode placements between consensual and nonconsensual electroconvulsive therapy: retrospective chart review study

## TL;DR

The study found that nonconsensual electroconvulsive therapy (ECT) is more likely to use a type of electrode placement linked to greater cognitive impairment.

## Contribution

The study is the first to show a significant association between ECT consent status and electrode placement in clinical practice.

## Key findings

- Nonconsensual ECT was significantly more likely to use bitemporal electrode placement.
- Bitemporal ECT is associated with higher cognitive impairment compared to other placements.
- The association remained significant after adjusting for age, gender, education, and diagnosis.

## Abstract

Electroconvulsive therapy (ECT) is often used to treat severe mental disorders in individuals with impaired capacity to consent to the treatment. Little is known about how different types of electrode placement are used in consensual and nonconsensual ECT.

To investigate whether there was an association between ECT consent status and electrode placement, given that ECT electrode placement affects efficacy and cognitive outcomes.

Using a statewide database across 3 years in Victoria, Australia, we performed chi-squared tests to determine whether consent status (consensual versus nonconsensual) was associated with particular electrode placements. A three-way log–linear analysis was then conducted to examine whether age, gender, level of education and psychiatric diagnosis influenced the relationship between consent status and electrode placement. Given the comparable cognitive outcomes of right unilateral and bifrontal ECT, these electrode placements were combined in the analysis.

In total, 3882 participants received ECT in the Victorian public health service during the study period. In the nonconsensual ECT group, 722 of 1576 individuals (45.81%) received bitemporal ECT, compared with 555 of 2306 (24.06%) in the consensual group (χ
2 = 200.53; P < 0.0001; odds ratio: 2.6673, 95% CI: 2.3244–3.0608). This association remained significant after adjustment for gender, age, level of education and diagnosis.

Significantly more participants in the nonconsensual ECT group received bitemporal ECT rather than right unilateral or bifrontal ECT compared with those in the consensual group. As bitemporal ECT is associated with more cognitive impairment, this choice of electrode placement in vulnerable patients who lack capacity to consent raises ethical considerations in the practice of ECT.