The Autonomic Nervous System, Suicidal Ideation and ECT: New Review in JECT

Out on PubMed, from investigators in Georgia, is this review:

The abstract is copied below:

Abstract: Longitudinal observational studies have shown a meaningful

decrease in suicidal thinking and suicidal behavior after receipt of electroconvulsive

therapy (ECT). The antisuicide effect of ECT may be related to

success in the global relief of the presenting syndrome such as depressive

or psychotic illness.However, it is possible that the antisuicide effect is specific

to ECT per se, over and above the relief of the clinical syndrome. Electroconvulsive

therapy is associated with many observable neurochemical

and physiologic effects, and some of these may plausibly be specifically

linked to an antisuicide effect. The phenomenon of physiologic hyperarousal

has been named as a candidate mechanism driving the risk for suicide.

Hyperarousal is associated with decreased neuropsychological executive

function responsible for response inhibition and can lead to impulsive

action. The level of arousal within the autonomic nervous system (ANS)

can be assayed with the pupillary light reflex, electrodermal activity, or

with heart rate variability (HRV). This article summarizes the literature

on the effects of ECT on HRV 24 to 72 hours after a course of ECT and

finds evidence for increases in HRV, which indicates lower levels of arousal

in the ANS. This finding suggests that ECT-related reductions in ANS

arousal, presumably with corresponding improvements in response inhibition,

may be one mechanism whereby ECT reduces risk for suicide.

Key Words: arousal, electroconvulsive therapy, executive function, heart

rate variability, suicide

The review is here.

And from the text:

This is certainly a novel hypothesis, that increased parasympathetic tone of the ANS after ECT mediates the anti-suicide effect. Yes, it would be great to do prospective studies of the relevant variables, as Dr. McCall and co-authors call for.

I hope many ECT health care professionals will read this review and consider this very interesting take on one facet of the possible mechanism of action of ECT.