INTRODUCTION:

From the time it was introduced into psychia-try in 1938, electroshock treatment, also known as ECT (for electroconvulsive therapy), has been highly controversial. In fact, it has been so controversial that in the mid-1960s, its use decreased considerably in the Western world, under social pressure and with the introduction of neuroleptics. However, the use of this therapy has been increasing since the mid-1980s. In 1997, Québec Science magazine published an article showing that the number of ECT treatment sessions in Québec had nearly doubled between 1988 and 1995, increasing from 4,000 to 7,200 during that period, much to the chagrin of ECT opponents. Against this backdrop, the Minister of Health and Social Services of Québec commissioned the Agence d'évaluation des technologies et des modes d'intervention en santé (AETMIS) to assess the prac-tice of electroconvulsive therapy in Québec. The report contained herein examines the efficacy and risks of this therapeutic approach, as well as the conditions of its use in Québec. THE CONTROVERSY SURROUNDING ELECTROCONVULSIVE THERAPY ECT has been highly controversial since its inception. Its proponents maintain that it is one of the safest and most effective therapies available. Its opponents consider it to be a means of controlling behavior and an inhuman and degrading treatment, with significant adverse effects that are responsible for memory loss and irreversible brain damage. This controversy has been fuelled by insufficient evidence on the mechanisms of action, efficacy and risks of ECT. AN EVOLVING THERAPY The mechanism of action of ECT is still not understood. However, in recent decades, the knowledge base concerning the conditions requi-red to attain the therapeutic effect has evolved greatly. Originally, the convulsion produced by the application of an electric current was considered to be sufficient to obtain the therapeutic effect sought by ECT. This convulsion is triggered by depolariza-tion of the cerebral cortex neurons. We now know that the convulsion is necessary, but not sufficient, for treatment and that the therapeutic effect appears to result from the depolarization of deep cerebral structures. Commencing in the mid-1950s, unmodified ECT was replaced by modified ECT with general anaesthesia, the administration of a muscular relax-ant (curare-type agent), oxygenation of the patient, constant monitoring of the patient's vital signs, and, generally, the application of brief electrical pulses. During the same period, the right unilateral tech-nique, which appears to have less-pronounced adverse effects, increasingly replaced the bilateral technique (application of electrodes on both sides of the head). Today, ECT is therefore very different from the original technique. RISKS OF ECT The risks associated with ECT are of three orders physical complications, potential brain damage and negative consequences on cognitive functions. ECT PRACTICE IN QUÉBEC Data from the Régie de l'assurance maladie du Québec (Québec's health insurance board) show that ECT use has increased since 1988, in particular between 1988 and 1996. This increase is similar for both sexes and is slightly stronger for patients between 20 and 64 years of age than for patients 65 years of age and older. However, the use of ECT in children and adolescents is negligible. Between 1988 and 2001, the percentage of ECT treatment sessions administered in outpatient clinics increased from 18% to 28%. The nature of the data available does not permit comparison of the use of ECT for the various recognized indications of this treatment mode. The rate of use of ECT in Québec falls within the limits of the rates observed in the other industrial-ized countries. According to Canadian Institute for Health Information data for the years 1994 to 2000, Québec's rate of use of ECT in hospitalized patients is among the lowest in Canada. SUBSTITUTE TECHNOLOGIES Transcranial magnetic stimulation (TMS) and vagus nerve stimulation (VNS) appear to be promis-ing as ECT substitute technologies. However, accord-ing to the current state of knowledge, AETMIS is of the opinion that they must be considered to be experi-mental.

CONCLUSION:

The prevailing uncertainties regarding the efficacy and risks of ECT are still important. It is therefore necessary to gather further information on these issues. In addition, the use of ECT in cases of depression must be based on a rigorous treatment algorithm, in association with pharmacotherapy and psychotherapy. Moreover, the various depres-sion treatment modes must be accessible.