Electroconvulsive therapy (ECT) remains an important treatment option for severe depressive illness, but it can have side-effects, including permanent gaps in memory. Where minimising the intellectual side-effects of treatment has priority, then treatment to only one side of the head (unilateral ECT) is preferable; where the speed of clinical improvement is paramount, then bilateral ECT may be preferred. The choice of how ECT is administered should, where possible, be part of the process of informed consent.
There are strong, and sometimes conflicting, views about electroconvulsive treatment (ECT). It was for this very reason that the Department of Health commissioned reviews to summarise what is known about the benefits and side-effects of the procedure The review of patients’ experiences after ECT (Rose et al, 2003) confirmed that permanent gaps in memory, what Robertson & Pryor (2006, this issue) refer to as permanent amnesia, is a recognised and common side-effect after treatment. The review of clinical trials (UK ECT Review Group, 2003) found that the intellectual side-effects of ECT reflected mostly problems with memory, in particular amnesia. The gaps in memory were not restricted to personal autobiographical events. Few trials investigated the possibility of longer-term intellectual impairments, but those that did suggested that this was not a substantial problem (Carney & Geddes, 2003).
Does ECT have permanent non-memory effects?
Robertson & Pryor state that it is clear that ECT also has a serious permanent effect on intellectual functions apart from memory. This is not at all clear to me, and I will quote one of the cited studies to explain my puzzlement. Calev and colleagues reviewed the evidence about the non-memory side-effects of ECT: among the abilities tested were general IQ, language, perception, manual dexterity and attention. They concluded that such side-effects
‘usually do not exceed the effects of depression, when modern methods of ECT administration . . . are used. Following ECT, these functions progressively improve. At one week to seven months after ECT, performance is better than before ECT, probably because of the alleviation of both the effects of depression and of ECT’ (Calev et al,1995).
ECT is not a single entity
I would stress what is missing from Robertson & Pryor’s article. One of the cited studies suggested more than 20 years ago that it would be useful to tell patients that how ECT is administered has an important effect on its memory side-effects (Squire & Slater, 1983). The electrical stimulation in ECT can be given over both temples – bilateral ECT – or only one side of the head – unilateral ECT. The side of administration in unilateral ECT is opposite to the side of the brain more involved in language function. It was clear to Squire & Slater that unilateral ECT was associated with markedly less memory impairment and that memory side-effects were also of less concern to individuals so treated. The UK ECT Review Group’s more recent review of clinical trials confirmed that people treated with unilateral ECT regain normal alertness and orientation more quickly after individual treatments and are less likely to experience amnesia.
We should stop talking about ECT as a single entity, but refer instead to either bilateral or unilateral ECT; they are quite different in their side-effects. Robertson & Pryor’s article refers to the Royal College of Psychiatrists’ revised guidelines for ECT practitioners: these recommended that the choice of administration should, where possible, be part of the process of informed consent for ECT. Where minimising the intellectual side-effects of treatment has priority, then unilateral ECT is preferable. Where the speed of clinical improvement is paramount, as in life-threatening depressive illness, then bilateral ECT may be preferred.
Do we still need ECT?
You might wonder whether it would just be easier to stop using ECT. The review of clinical trials concluded that ECT remains an important treatment option for the management of severe depressive illness (UK ECT Review Group, 2003).
We do need high-quality collaborative studies. What we don’t need is more research done by patients for patients and by ECT practitioners for ECT practitioners (Carney & Geddes, 2003).
Declaration of interest
A.S. is Editor of the Royal College of Psychiatrists’ (2005) revised guidelines for ECT practitioners.
- © The Royal College of Psychiatrists 2006