More than 70 years since its introduction, electroconvulsive therapy (ECT) remains the most effective somatic treatment in psychiatry, with unsurpassed efficacy and remarkable safety. ECT is effective for various conditions and is a viable treatment option when pharmacotherapy and psychotherapy have failed, when affective, psychotic or catatonic symptoms are present, and when rapid relief of symptoms is required because of suicide risk or deterioration of medical conditions [1
]. ECT is most commonly used for the treatment of severe depression, but is also effective for the treatment of manic or mixed episodes [7
Many patients with mood disorders, for which treatment with ECT is indicated, suffer from conditions that are chronic and recurrent in nature. Continuation therapy after remission of an acute episode of a mood disorder is considered to be the standard of practice in modern psychiatry [10
]. Following successful treatment with acute ECT, continuation therapy is of particular importance, as these patients frequently have the most severe, recurrent and treatment-resistant illness. A study by Sackeim et al. [11
] demonstrated that the relapse rate of patients with unipolar depression who remit after an acute course of ECT is extremely high if there is no active treatment after the last ECT. Patients who received placebo relapsed at a rate of 84% within 6 months after acute ECT. Patients who received monotherapy with the tricyclic antidepressant nortriptyline relapsed at a rate of 60%, and those receiving combination therapy consisting of nortriptyline and lithium relapsed at a rate of 39%. These results underscore the need for aggressive preventative approaches to sustain the clinical benefits of acute treatment.
When ECT is used for the treatment of an acute episode, it is reasonable to consider continuation ECT (C-ECT) or maintenance (M-ECT) to prevent relapse of the current episode or recurrence of a new episode. The term ‘continuation ECT’ (C-ECT) and ‘maintenance ECT’ (M-ECT) are frequently used interchangeably and indiscriminately across the mood disorder treatment continuum. For the purpose of this report, we will use the following definitions: an index/acute course is the initial series of treatments given for the purpose of relieving acute symptoms of the illness. C-ECT is a course that begins after the index course, lasts up to 6 months, and is designed to prevent relapse of the episode (return of the symptoms to full syndromal criteria before the end of the natural duration of the illness). M-ECT is a course that begins after the end of C-ECT and is intended to prevent recurrence of an episode (a new episode).
The practice of C-ECT and M-ECT has been documented almost since the introduction of ECT by Cerletti and Bini in 1938 [12
]. However, it has not always been widely implemented in clinical practice during the psychotropic medication era of modern psychiatry. The development of antipsychotic and antidepressant medications in the 1950s created the belief that ECT had been superseded, and the practice of ECT declined dramatically. This period, which lasted until the early 1970s, was characterized by the polemics of the antipsychiatry movement which attacked psychiatry in general and ECT in particular [14
]. ECT, despite its decline in numbers, was never abandoned, as many patients did not respond to medications and psychotherapy. However, the negative climate prompted many psychiatrists to recommend as few treatments as possible, often limiting the number of ECT treatments to the absolute minimum to achieve improvement of acute symptoms, thus automatically excluding C-ECT and M-ECT from their armamentarium. In 1974, the American Psychiatric Association (APA) appointed a Task Force to study and report on ‘[ECT] legislative issues, consent, indications for its use and possible increasing use …’ [15
]. The Task Force reported that there was a role for ECT in the treatment of depression, intractable mania and treatment-resistant schizophrenia [15
]. There was no particular mention of C-ECT in that report, yet interest in the practice of ECT was restimulated.
A survey of practice by Kramer [16
] conducted in 1986 revealed that many psychiatrists were treating their most treatment-resistant patients with C-ECT. C-ECT was first mentioned in the 1990 APA Task Force report [17
]. The third and latest APA Task Force Report (2001) [3
] established the indications for C-ECT and M-ECT for patients who responded to an acute ECT course when one of the following has occurred:
(1) pharmacotherapy alone has not been effective in treating index episodes or in preventing relapse or recurrence;
(2) pharmacotherapy cannot be safely administered, or
(3) the patient prefers treatment with ECT and the patient or surrogate consentor agrees to the patient's receiving C-ECT. The patient must be capable, with the assistance of others, of complying with the treatment plan.
The Association for Convulsive Therapy (ACT), a professional society of ECT clinicians and researchers, created a task force that recommended guidelines for the practice of ambulatory ECT [18
]. As most C-ECT and M-ECT is performed on an outpatient basis, the majority of these guidelines are applicable and should facilitate this practice. Nevertheless, as we pointed out in an earlier review [19
], there is little early systematic research on C-ECT and M-ECT. Many case reports and several studies appeared in the literature until 1965, attesting to the utility of ECT courses given beyond the point of acute treatment [20
]. Inherent weaknesses of these studies, as in most of the psychiatric literature of that era, include the use of heterogeneous populations and weak methodology.
One would have expected a much greater number of research publications on C-ECT and M-ECT over the course of more than 7 decades, especially considering the almost unanimously positive attestations of the reports. This lack of literature between 1965 and 1985 reflects, besides the decline in the use of ECT, the fact that C-ECT is underused and that research resources directed to the study of ECT are limited. One cannot underestimate the effects of the negative public environment regarding ECT on scientific thinking and directions of scientific research. The stigma against ECT is perpetrated even by professionals, as evidenced by the National Institute for Clinical Excellence (NICE) report in the UK, which disputed the utility of C-ECT and M-ECT in its ‘Guidance on the Use of Electroconvulsive Therapy’ [21
], despite positive recommendations from the APA Task Force on ECT and protest from British psychiatrists [22
]. We responded to this report with a paper in the Journal of ECT
] which documents the logical inconsistencies in the flawed British report.
With the renewal of interest in ECT, more reports about C-ECT were published during the last two decades. These studies reconfirm the benefits of ECT given beyond the index course. Unfortunately, most of these reports are retrospective and describe only a small number of patients. Prolonging remission after successful acute treatment with ECT remains an important clinical challenge. If C-ECT is implemented, common clinical practice includes a taper and then treatments spaced out at gradually increasing intervals. However, there is a dearth of guidance about the optimal frequency of C-ECT, concurrent pharmacotherapy and the overall tolerability of C-ECT.
At the time of our earlier review in 1997, C-ECT and M-ECT were not often considered as options. However, newer research and experience have established C-ECT and M-ECT as important tools for relapse prevention in patients who have responded to ECT for the treatment of an acute episode of a mood disorder. The aim of this report is to review the literature on C-ECT and M-ECT after 1997 and to delineate evidence-based guidelines for its safe and effective practice.