More about the Manchester ECT-ketamine study

Last Sunday’s Observer printed an article about a letter, signed by nine psychologists and psychiatrists, raising concerns about the Manchester ECT and ketamine study. The letter was sent to participating NHS trusts, funding bodies and ethics committees (and, presumably, the media). A copy of the letter can be read on the blog of one of the signatories, Professor John Read of Liverpool University. The Observer article rather confusingly identified writer and psychologist Oliver James as one of those raising concerns, although his signature is not on the letter.

The Manchester ECT and ketamine study (details here ) plans to recruit 160 patients undergoing ECT in six trusts and give some of them an injection of ketamine with the anaesthetic for ECT. This, they say, stands a chance of not only enhancing the therapeutic effect of ECT, but also reducing the effects on memory. “Small studies have suggested that combining ketamine with ECT can protect against the detrimental effects of ECT on thought processes and hasten the speed of getting better from depression.” According to the protocol, which can be read here it is the neuroprotective effect of ketamine that is the primary objective.

“Adverse cognitive effects are a major reason for ECT’s poor acceptability and unfavourable benefit-risk balance. The key clinical rationale for this study is to determine the degree to which adjunctive ketamine prevents ECT-induced cognitive impairment.”

The research is sponsored by the Manchester Mental Health & Social Care Trust. Interestingly, the Greater Manchester West Mental Health NHS Trust (“Improved lives, optimistic futures”) is not one of the participants. They have published a Focus on… Electroconvulsive Therapy. The lead ECT nurse from GMW’s Bolton Mental Health Directorate, and a member of the National Association of Lead ECT Nurses (NALNECT) explains:

“The procedure involves the administration of a sedative and muscle relaxant before a carefully controlled electronic [electronic?] current is passed through the patient’s brain inducing a seizure which is necessary for the treatment to work…. Commonly reported side effects include short term memory loss, headaches, stiffness and confusion. However, these side affects can be associated with any procedure requiring anesthetic, and the effects usually wear off within a couple of hours.”

Presumably they think that such minor side effects don’t merit the experimental use of ketamine.

The evidence to date that ketamine might protect against the damaging effects of ECT on memory and cognition seems rather slight – a few small studies suggesting that it might be worth investigating. This, then, is the rationale for the study. But why does it cost over a million pounds? After all, the patients would be having ECT anyway so there is no cost there; an injection of ketamine isn’t costly; and a few tests of cognitive function, etc, can’t be too expensive either. The cost must be in the MRI scans and near infra-red spectroscopy that the researchers are carrying out in order to investigate the effect on neural networks. Why not see if ketamine makes any difference before sinking so much money in these investigations?

The protocol starts off with the usual doom and gloom paragraph about the enormous numbers of depressed people and the great cost of depression:

“At least 3% of the UK population meet criteria for major depression at any one time… the annual treatment costs for depression in 2000 were estimated at £370 million with £8.5 billion in indirect costs… The key clinical rationale for this study is to determine the degree to which adjunctive ketamine prevents ECT-induced cognitive impairment. If it does to a clinically important degree then standard ECT practice will be altered nationally and internationally and the improvement of the benefit:risk balance of ECT will be a substantial benefit to patients and inform future ECT research.”

I think the last sentence may be rather inflating the importance of this study (and I suppose you have to big it up a bit if you want a million pounds). After all, there are plenty of studies concluding that unilateral ECT does less damage than bilateral, but they have had minimal impact on ECT practice in Britain, which is still predominantly bilateral.