title: [Electroconvulsive therapy and level of evidence: From causality to dose-effect relationship].
abstract: OBJECTIVE
  The first objective of this article is to summarize the history of electroconvulsive therapy (ECT) in psychiatry in order to highlight the transition from clinical level of evidence based on phenomenological descriptions to controlled trial establishing causal relationship. The second objective is to apply the criteria of causation for ECT, to focus on the dose-effect relationship criteria, and thus to analyze the conditions of application of these criteria for ECT.
  
  
  METHODS
  A literature review exploring the use of electricity, ECT and electroencephalography (EEG) in psychiatry was conducted. The publications were identified from the Pubmed and GoogleScholar electronic databases. The scientific literature search of international articles was performed in July 2016.
  
  
  RESULTS
  In 1784, a Royal commission established in France by King Louis XVI tested Mesmer's claims concerning animal magnetism. By doing that, the commission, including such prominent scientists as the chemist Anton Lavoisier and the scientist and researcher on electricity and therapeutics Benjamin Franklin, played a central role in establishing the criteria needed to assess the level of evidence of electrical therapeutics in psychiatry. Surprisingly, it is possible to identify the classical Bradford Hill criteria of causation in the report of the commission, except the dose-effect relationship criteria. Since then, it has been conducted blinded randomized controlled trials that confirmed the effectiveness of ECT against ECT placebos for the treatment of psychiatric disorders. At present, the dose-effect relationship criteria can be analyzed through an EEG quality assessment of ECT-induced seizures.
  
  
  CONCLUSIONS
  EEG quality assessment includes several indices: TSLOW (time to onset of seizure activity ≤5Hz, seconds), peak mid-ictal amplitude (mm), regularity (intensity or morphology of the seizure (0-6)), stereotypy (global seizure patterning, 0-3) and post-ictal suppression (0-3). A manual rating sheet is needed to score theses indices. Such manual rating with example of EEG segments recording is proposed in this article. Additional studies are needed to validate this manual, to better establish the dose-response relationship for the ECT, and thus strengthen the position of the EEG as a central element for clinical good practice for ECT.
authors.affiliation: Service d'explorations fonctionnelles du système nerveux, Clinique du sommeil, CHU de Bordeaux, Place Amélie Raba-Léon, 33076 Bordeaux, France. Electronic address: jarthur.micoulaud@gmail.com.
authors.forename: J-A
authors.initials: JA
authors.lastname: Micoulaud-Franchi
authors.affiliation: Unité d'électroconvulsivothérapie, CH Charles Perrens, 33000 Bordeaux, France.
authors.forename: C
authors.initials: C
authors.lastname: Quilès
authors.affiliation: SHU Psychiatrie Adultes, Hôpital Sainte Marguerite, 13274 Marseille Cedex 9, France.
authors.forename: M
authors.initials: M
authors.lastname: Cermolacce
authors.affiliation: SHU Psychiatrie Adultes, Hôpital Sainte Marguerite, 13274 Marseille Cedex 9, France.
authors.forename: R
authors.initials: R
authors.lastname: Belzeaux
authors.affiliation: SHU Psychiatrie Adultes, Hôpital Sainte Marguerite, 13274 Marseille Cedex 9, France.
authors.forename: M
authors.initials: M
authors.lastname: Adida
authors.affiliation: Service de Psychiatrie Adultes, CHU Saint-Étienne, 5 chemin de la Marendière, 42055 Saint-Etienne Cedex, France.
authors.forename: E
authors.initials: E
authors.lastname: Fakra
authors.affiliation: SHU Psychiatrie Adultes, Hôpital Sainte Marguerite, 13274 Marseille Cedex 9, France.
authors.forename: J-M
authors.initials: JM
authors.lastname: Azorin
mesh_terms: D000818:Animals; D004565:Electroconvulsive Therapy / Q000009:adverse effects / Q000266:history / Q000379:methods; D004569:Electroencephalography; D019317:Evidence-Based Medicine; D049671:History, 18th Century; D049672:History, 19th Century; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D012640:Seizures / Q000175:diagnosis / Q000266:history / Q000628:therapy*
keywords: Causality; Causalité; Dose-effect relationship; Electroconvulsive therapy; Electroencephalography; Level of evidence; Neurophysiologie; Neurophysiology; Niveau de preuve; Relation dose-effet; Électroconvulsivothérapie; Électroencéphalographie