Some researchers (two psychiatrists and an anaesthetist) in Edinburgh, Scotland, have been looking at asystole during electroconvulsive therapy (ECT) and whether it is more likely to occur with subconvulsive shocks. Asystole is a pause in heartbeat, defined in this study as lasting for at least 5 seconds. Nonconvulsive shocks are given during the initial ECT session when a person’s seizure threshold is being established by giving them shocks of increasing strength until one causes a seizure. The article (The cardiovascular safety of the empirical measurement of the seizure threshold in electroconvulsive therapy, by L Mizen, C Morton and A Scott) was published by the Psychiatric Bulletin and can be read here.
The researchers found that asystole occurred in 5 per cent of stimulations, as they called the electric shocks, and was no more common with subconvulsive ones than with convulsive ones. There were no adverse outcomes and the authors concluded that “There was no evidence that the empirical measurement of the seizure threshold added to the cardiovascular risk of ECT”.
The researchers included a table of the “Demographics of the study sample”, that is the 50 people who were undergoing their first ECT session of a course, and so the article gives an interesting glimpse into how ECT is used in Edinburgh. The sample consisted of “53 consecutive patients referred for a new course of ECT at the Royal Edinburgh Hospital between 12 February 2008 and 5 March 2010” (3 patients being excluded because they were given an anticholinergic drug with the anaesthetic). If they were consecutive patients then presumably they included patients who hadn’t consented to ECT but were being treated as lacking capacity under Mental Health law and so presumably consent wasn’t required for the study, as it only involved analysis of the “printed paper record of the electrocardiogram”. The authors don’t mention consent. The Scottish ECT Audit Network meanwhile give much higher figures for ECT use at the hospital during 2008-2010, so I can’t work out exactly what is going on.
The demographics table showed that the mean age of the patients was 57 (range 22 to 87 years) and that 74 per cent were women. Bilateral electrode placement was used in 47 patients (94 per cent). These figures are fairly typical of ECT use in the United Kingdom, but what is more surprising is the range of diagnoses for which the patients were being treated. Thirty-two of the 50 patients (64 per cent) were being treated for severe depression or bipolar affective disorder. A further 6 had a diagnosis of depression, but its severity was not specified. Six had moderate depression, one had mild depression, 3 had schizophrenia (one with severe depression) and one had Alzheimer’s disease (with severe depression).
It is interesting to compare that variety of diagnoses with what psychiatrists say about ECT use. For example, the Royal College of Psychiatrists’ patient information leaflet on ECT has this to say:
“Q Who is ECT likely to help?
Someone who has severe depression, resistant mania or catatonia. ECT should be considered for the rapid treatment of severe depression that is life-threatening, or when other treatments have failed.
It should not be used routinely in moderate depression. It can be helpful for someone with moderate depression if they have not responded to several different drug treatments and psychological treatment.
Q Who is ECT unlikely to help?
ECT is unlikely to help someone with mild to moderate depression or most other psychiatric conditions. It is not used in schizophrenia.”
It would appear from the study at the Royal Edinburgh Hospital that the Royal College was wrong to state categorically that ECT is not used in schizophrenia, and perhaps they should be asking why it is still being used on people with mild depression if it is unlikely to help them.