Hypnotherapy for major depressive disorder: a systematic review of randomized clinical trials

ABSTRACT Introduction: Major Depressive Disorder (MDD) is one of the most debilitating diseases worldwide and has seen a significant increase in diagnoses during the pandemic, demanding more and better therapeutic tools to manage the post-pandemic scenario. Objective: The aim of this systematic review is to provide a comprehensive analysis of the last 20 years of clinical research on Hypnotherapy (HT) to determine whether this intervention has evidence to support its recommendation for the treatment of MDD. Methods: This review included only randomized clinical trials (RCTs) involving adult populations diagnosed with MDD, regardless of the severity level (mild, moderate, or severe) according to any validated diagnostic criteria, compared to a control group (active treatment or none), with any follow-up duration and free access to the manuscript. The bibliographic survey was planned to be as sensitive as possible, conducted across seven distinct databases: MEDLINE (PubMed), Embase, CENTRAL, PsycINFO, Scopus, ScieELO, and Latin American and Caribbean Health Sciences Literature (LILACS). To identify potentially eligible studies in the grey literature, researchers also searched the U.S. National Library of Medicine (ClinicalTrials.gov). The risk of bias was assessed by two independent investigators using Cochrane’s revised tool (RoB 2), and the final judgment was made by consensus. To better analyze the included studies, the certainty of the evidence was evaluated through the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Due to the lack of comparable studies, it was not possible to perform a meta-analysis; therefore, the studies were graphically displayed in Descriptive Forest Plots. Results: There is very low-quality evidence suggesting that hypnosis-based interventions may reduce the severity of depression, which precludes the clinical recommendation of this intervention for patients in the real world, pending the production of better evidence of effectiveness and safety, although no evidence of significant adverse effects was found. Other: This review was pre-registered with PROSPERO and can be accessed using the registration number CRD42023409631. Competing Interest Statement The lead author of this review has been a hypnotherapist for 7 years and currently works as the clinical director of a psychology clinic in Brazil that also offers hypnotherapy services. The co supervisor of this work is the editor-in-chief of the International Journal of Clinical and Experimental Hypnosis (IJCEH). Funding Statement This review did not receive any institutional or industrial financial support. Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data Availability All data produced in the present work are contained in the manuscript