title: The Self-help Online against Suicidal thoughts (SOS) trial: study protocol for a randomized controlled trial.
abstract: Suicidal thoughts are common, causing distress for millions of people all over the world. However, people with suicidal thoughts might not access support due to financial restraints, stigma or a lack of available treatment offers. Self-help programs provided online could overcome these barriers, and previous efforts show promising results in terms of reducing suicidal thoughts. This study aims to examine the effectiveness of an online self-help intervention in reducing suicidal thoughts among people at risk of suicide. The Danish Self-help Online against Suicidal thoughts (SOS) trial is a partial replication of a previously conducted Dutch trial.
  
  
  
  A randomized, waiting-list controlled trial with 1:1 allocation ratio will be carried out. A total of 438 people with suicidal thoughts will be recruited from the Danish suicide hotline, The Lifeline's, website and allocated to the intervention condition (N = 219) or the control condition (N = 219). The intervention condition consists of a 6-week, Internet-based self-help therapy intervention. The format of the intervention is self-help, but the participants can be guided by the trial manager. The control condition consists of a waiting-list assignment for 32 weeks. The primary outcomes are frequency and intensity of suicidal thoughts. Secondary outcome measures include depressive symptoms, hopelessness, worrying, quality of life, costs related to health care utilization and production loss. Number of deliberate self-harm episodes, suicides and deaths will, as well as the participant's evaluation of the intervention and the experience of negative effects, be investigated. Assessments will be conducted over the intervention website through self-report questionnaires at baseline, 2 weeks, 4 weeks, 6 weeks and 32 weeks (6 months post intervention).
  
  
  
  If we find the intervention to be linked to reductions in suicidal thoughts, this will strengthen the evidence that online self-help interventions are relevant tools for people with suicidal thoughts.
  
  
  
  ClinicalTrials.gov, NCT02872610 . Registered on 9 August 2016.
authors.affiliation: Danish Research Institute for Suicide Prevention, Mental Health Centre Copenhagen, Kildegårdsvej 28, 2900, Hellerup, Denmark. Charlotte.Muehlmann@regionh.dk.
authors.forename: Charlotte
authors.identifier: 0000-0001-9793-1626
authors.initials: C
authors.lastname: Mühlmann
authors.affiliation: Danish Research Institute for Suicide Prevention, Mental Health Centre Copenhagen, Kildegårdsvej 28, 2900, Hellerup, Denmark.
authors.forename: Trine
authors.initials: T
authors.lastname: Madsen
authors.affiliation: Copenhagen University Hospital, Mental Health Centre Copenhagen, Kildegårdsvej 28, 2900, Hellerup, Denmark.
authors.forename: Carsten
authors.initials: C
authors.lastname: Hjorthøj
authors.affiliation: Department of Clinical, Neuro, and Developmental Psychology and the EMGO Institute for Health and Care Research, Faculty of Behavioural and Movement Sciences Vrije Universiteit Amsterdam, Van der Boechorststraat 1, 1081 BT, Amsterdam, The Netherlands.
authors.forename: Ad
authors.initials: A
authors.lastname: Kerkhof
authors.affiliation: Danish Research Institute for Suicide Prevention, Mental Health Centre Copenhagen, Kildegårdsvej 28, 2900, Hellerup, Denmark.
authors.forename: Merete
authors.initials: M
authors.lastname: Nordentoft
authors.affiliation: Danish Research Institute for Suicide Prevention, Mental Health Centre Copenhagen, Kildegårdsvej 28, 2900, Hellerup, Denmark.|Department of Mental Health, John Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.|Department of Regional Health Research, University of Southern Denmark, Odense, Denmark.
authors.forename: Annette
authors.initials: A
authors.lastname: Erlangsen
mesh_terms: D002985:Clinical Protocols; D003718:Denmark; D006801:Humans; D020407:Internet; D011569:Psychiatric Status Rating Scales; D012107:Research Design; D012657:Self-Help Groups; D059020:Suicidal Ideation; D013405:Suicide / Q000523:psychology; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome; D000092864:Suicide Prevention
keywords: Cognitive behavioral therapy; Internet intervention; Online intervention; Randomized controlled trial; Self-help; Suicidal ideation; Suicidal thoughts