Mania, acute schizophrenia and catatonia

In the new edition of The ECT Handbook, the College’s recommendations regarding indications in mania (Box 2), acute schizophrenia (Box 3) and catatonia (Box 4) now go beyond statements about whether or not ECT has efficacy, and also offer guidance on the place of ECT among other treatments. The revision includes a critical appraisal of the evidence base for the efficacy of ECT in schizophrenia that led to the recommendation that ECT be restricted to the treatment of acute schizophrenia, and only then once clozapine has already proven ineffective or intolerable.

The recommendations for these indications are consistent with the NICE guidance (National Institute for Clinical Excellence, 2003b ), although the latter does not include other neuropsychiatric conditions such as Parkinson’s disease.

Depressive illness

The College and NICE differ in their recommendations regarding indications for ECT in depressive illness (Boxes 5 & 6). The College suggests indications where ECT may be the treatment of choice or considered as a first-line treatment aside from immediately life-threatening or demonstrably treatment-resistant depressive illness. The College had already argued in its appeal to NICE that it seemed perverse that depressed patients might have to wait until their depressive illness became life-threatening or had failed to respond to other treatments before they would be allowed ECT. The revised College guidance does accept that there is no evidence from a randomised controlled trial to support the efficacy of ECT as a prophylactic treatment, but foresees clinical scenarios where, through a process of informed consent, a patient might choose ECT as the preferred treatment.

Box 7 lists suggestions to prescribers about how to accommodate their practice while this discrepancy between guidance from the College and NICE continues. The key here is that appropriate treatment decisions are made for the individual patient through the process of valid informed consent. The systematic review by Reference Rose, Wykes and LeeseRose et al(2003) has emphasised that patients who have previously been treated with ECT have the experience to decide whether to trade off the immediate benefit with the potential for later problems such as retrograde amnesia. Patients who have never been treated with ECT have no such personal experience, and greater circumspection would be required here. The prescription of unilateral ECT would be particularly apposite (see Prescription below).

Treatment resistance

NICE recommends as a general principle that ECT be used only after an adequate trial of other treatments has proven ineffective, if the illness is not considered life-threatening. No guidance is offered on what can be regarded as adequate other treatments for any of the conditions appraised.

The most common contemporary indication for ECT is treatment-resistant depressive illness (Reference Duffett, Siegert and LelliottDuffett et al, 1999; Scottish Electroconvulsive Therapy Audit Network, 2002), and it is particularly disappointing that NICE offers no guidance on this. However, the College’s revised ECT Handbook does contain advice on what constitutes treatment resistance in depressive illness, suggesting options in addition to ECT for its management. These are based on the earlier evidence-based guidelines of the British Association for Psychopharmacology (Reference Anderson, Nutt and DeakinAnderson et al, 2000). In the absence of an urgent need for treatment, ECT is not regarded as the second-line treatment of choice (Box 8).

Traditionally, it was held that ECT is a highly efficacious treatment for depressive illness irrespective of whether or not that illness had already failed to respond to antidepressant drug treatment. This belief has been challenged by well-conducted prospective research in the USA (see Reference Van den Broek, de Lely and Muldervan den Broek et al, 2004), which suggested that among contemporary patients with depression, a history of a failure to recover with antidepressant drug treatment reduced the likelihood of recovery with subsequent ECT. These findings in the USA have not been replicated in The Netherlands (Reference Van den Broek, de Lely and Muldervan den Broek et al, 2004) or in Scotland (Reference Husain, Kevan and LinnellHusain et al, 2004). This suggests that the prediction of the likelihood of recovery with ECT cannot be based on treatment resistance alone. Patients in whom the index illness has proved resistant to medical treatment may also have a history of previous recovery with ECT. Episodes of treatment-resistant illness also last longer and it is not clear whether it is treatment resistance itself or the longer duration of the index illness that may be associated with a redcued likelihood of recovery with ECT. The literature is, however, consistent in that the majority of patients who have already failed to recover with antidepressant drug treatment can subsequently recover with ECT.

Electrode placement

It is the selection of electrode placement by the prescriber that has the most profound effect on the cognitive adverse effects of ECT. Patients treated with bilateral ECT take significantly longer to become reoriented after an individual treatment (Reference Sackeim, Prudic and DevanandSackeim et al, 2000) and are at greater risk of prolonged disorientation (Reference Sackeim, Prudic and DevanandSackeim et al, 2000). The risk of the loss of autobiographical memories was emphasised as a particular concern in the systematic review of patients’ perspectives on ECT. Such gaps in memory, or retrograde amnesia, covering the months, or occasionally years, before the course of ECT are more likely to persist 2 months after treatment with bilateral ECT (Lisanby et al, 2000). The College’s Special Committee on ECT appreciated that many practitioners in the UK were sceptical about unilateral treatment because of earlier experiences of limited efficacy of unilateral ECT given with an inadequate electrical stimulus. Unilateral ECT with attention to stimulus dosing can be an efficacious treatment for a substantial proportion of patients with depression (Reference Sackeim, Prudic and DevanandSackeim et al, 2000), albeit that there will continue to be some who will not recover even with high-dose unilateral ECT, but who subsequently recover with bilateral ECT (Reference Sackeim, Prudic and DevanandSackeim et al, 2000).

Frequency of treatment

The recommendation remains that the optimal frequency for both bilateral and unilateral ECT is twice a week. The frequency may be reduced to, say, weekly to manage treatment-emergent cognitive adverse effects, or as the course of treatment nears completion.

Number of treatments

The recommendation remains that a set number of treatments should not be prescribed at the start of a course of ECT. The patient should be assessed after each treatment to see if further treatments are necessary. If no clinical improvement is seen at all after six properly given bilateral treatments, then the course should be abandoned as lacking efficacy. The management of patients who have shown definite but slight or temporary improvement with early treatments is more complex, but it may be worth continuing up to 12 bilateral treatments before abandoning ECT. As noted above, some patients do not respond even to high-dose, unilateral ECT, but subsequently respond to bilateral ECT. The ineffective unilateral treatments should be disregarded in the assessment of the need for further bilateral treatments.

Before ECT

Wherever clinically possible, the concomitant prescription of a benzodiazepine drug should be avoided during a course of ECT. If a hypnotic drug is indicated, a small dose of a sedative antipsychotic may be preferred to a benzodiazepine. Nevertheless, it would be incautious suddenly to stop prescribing a long-established benzodiazepine a few days before a course of ECT, because there is a risk of a dramatic lowering of seizure threshold. It may be better to continue the drug initially, perhaps in reduced dosage. Abrupt discontinuation of an antidepressant before ECT should also be avoided, particularly one with a short half-life or one of the serotonin specific reuptake inhibitors (SSRIs), because of the risk of discontinuation symptoms. Another reason is that there have been case reports of prolonged cerebral seizure activity putatively linked to the abrupt discontinuation of an antidepressant, usually an SSRI. A special note is required about non-selective monoamine oxidase inhibitors (MAOIs). Traditionally, there has been concern about the administration of any general anaesthetic to patients taking such a drug in case a pressor drug were required to treat peri-operative hypotension. This is not of practical relevance to ECT and the available evidence does not suggest any other reason that an MAOI need be discontinued before treatment. Nevertheless, it is prudent that the anaesthetist be informed if a patient might have taken an MAOI drug within 2 weeks of the start of a course of ECT. The co-administration of lithium is not a contraindication to ECT. If an anti-epileptic drug is prescribed to treat epilepsy, then its prescription should continue. If an anti-epileptic drug is used as a mood stabiliser, then no evidence-based recommendation can be made; on balance, it may be better to continue prescription during the course of ECT (see below).

After ECT

It has been established for more than 30 years that there is a high risk of relapse in the first few weeks after successful ECT if patients are left untreated. It has been a long-standing recommendation that the minimum requirement after successful ECT is continuation medical treatment with an antidepressant drug at a full therapeutic dose for at least 6 months. In depressive illness, there is evidence that ECT is reserved for treatment-resistant illnesses and this might suggest that continuation medical treatment would be routine after ECT. Surprisingly, there have been reports from North America that this practice is not routine, although it is not clear whether this is a problem of prescription or adherence. The recommendation for 6 months of continuation treatment must be seen as the bare minimum, and certainly 12 months of continuation treatment has been recommended as routine practice in late-life depressive illness (Reference Baldwin, Anderson and BlackBaldwin et al, 2003). It is probably better to prescribe an effective antidepressant drug and/or mood stabilising drug before the end of a course of treatment, if only to provide adequate early continuation treatment. Most contemporary patients treated with ECT suffer from recurrent illness and are therefore likely to be candidates for longer-term prophylactic treatment as well as continuation treatment. Evidence-based recommendations for prophylactic treatment are available for depressive illness (Reference Anderson, Nutt and DeakinAnderson et al, 2000), bipolar disorder (Reference GoodwinGoodwin, 2003) and schizophrenia (American Psychiatric Association, 1997).

Gaps in the evidence

Unfortunately, there is a lack of relevant clinical research to inform the management of the continuation phase of treatment in patients with depression who were originally prescribed ECT because the index illness had not responded to antidepressant drug treatment. There is one school of thought that ECT brings about neurochemical changes that make a depressive illness more likely to respond to antidepressant drug treatments, including those that have not previously been effective. Other commentators disagree and recommend that after successful ECT, a switch be made to a different class of antidepressant drug rather than reintroduce a drug from a class that has already proved ineffective. It may be prudent to assume that such patients, like those who suffer from recurrent depressive illness, are candidates for an augmentation strategy as well as continuation treatment with an antidepressant drug.