The scientific status of electro-convulsive therapy

Abstract

Electro-convulsive therapy (ECT) has been available for just over 40 years, whereas neuroleptic drugs have recently celebrated their 25th anniversary. Yet much more is known of the magnitude and scope of effectiveness, the mechanism of action, and even the adverse effects, of neuroleptic drugs in the treatment of schizophrenia than of electro-convulsive therapy in depression. Research on drug therapy of schizophrenia has advanced rapidly in the past 15 years while clinical research on ECT has progressed little. Until recently, basic research on possible mechanisms of action was also very limited.It seems unlikely that this state of affairs presages the demise of convulsant therapy as a major treatment modality. Despite criticisms from a number of sources, most psychiatrists remain convinced that ECT has a unique place in the treatment of depression. Yet it is an entirely empirical treatment. In this respect it is far from unique in medicine; but it must be unusual for a treatment to remain widely used and so little understood for so long a period.Advances in understanding mechanisms of action are desirable but many purely clinical questions remain unanswered. The Department of Health and Social Security and the Royal College of Psychiatrists are ascertaining the extent to which ECT is now used in British hospitals. It seems possible that a number of smaller projects, if properly designed, could provide answers to some outstanding questions concerning the scope and indications for this treatment. Such answers might substantially influence current practice, based as it is on information from trials carried out when antidepressant medications were relatively new, and to a large extent upon the individual clinician's intuition. EFFECTIVENESS IN DEPRESSIONIn an attempt to obtain an overall view of the effectiveness of ECT in comparison with other therapies, Wechsler et al. (1965) summarized 153 studies published between 1958 and 1963 in American, British and Canadian journals, involving a total of 5864 patients. They present the figures shown in Table 1.Since many studies were uncontrolled, and these studies showed higher rates of improvement than those with a control group, these figures almost certainly exaggerate the effectiveness of antidepressant treatments, including ECT. More cogent perhaps is the contrast which these authors were able to demonstrate in the findings of studies dealing with depressions of recent onset and those which included mainly chronic depressions (but also some schizophrenic patients) (see Table 2). The superiority of both drugs and ECT over placebo is much less in the latter group.No firm conclusions can be drawn from a literature survey. Patient selection is uncontrolled and many studies in which ECT was compared directly with other treatments included small numbers of patients. The soundest basis for an assessment of the efficacy of ECT are 2 major controlled trials completed in the early 1960s. The first (Greenblatt et al. 1962(Greenblatt et al. , 1964, in the United States, included ...

Statistics and the nature of depression

“…The size of this trial, however, was totally inadequate to demonstrate any significant treatment differences. Methodological criticisms of other early trials of ECT can be found in Crow (1979). Unfortunately, inconsistent trial results and methodological criticisms of the early clinical trials enabled influential authors such as Sargant & Slater (1944 to continue to advocate the use of physical treatments on the basis of anecdotal evidence and personal prejudices.…”

Statistics and the Nature of Depression

“…The size of this trial, however, was totally inadequate to demonstrate any significant treatment differences. Methodological criticisms of other early trials of ECT can be found in Crow (1979). Unfortunately, inconsistent trial results and methodological criticisms of the early clinical trials enabled influential researchers such as Sargant andSlater (1944, 1963) to continue to advocate the use of physical treatments on the basis of anecdotal evidence and personal prejudices.…”

Local cerebral glucose utilization after chronic electroconvulsive shock: implications for the mode of action of electroconvulsive therapy

“…Much of the available neuropharmacological data lacks anatomical detail and similar changes have not been demonstrated in humans. Little interest has focused on sub-convulsive stimulation of the brain, for it is accepted (Cronholm and Ottosson, 1960)-albeit on the basis of equivocal evidence (Crow, 1979;Deakin, 1983;Royal College of Psychiatrists, 1977)-that sub-convulsive ECT has no therapeutic benefit. Animal studies of subconvulsive ECS have demonstrated no neuropharmacological changes.…”