Effectiveness of Online Self-Help for Suicidal Thoughts: Results of a Randomised Controlled Trial Bregje A. J. van Spijker 1,2 *, Annemieke van Straten 2 , Ad J. F. M. Kerkhof 2 1 Centre for Mental Health Research, Australian National University, Canberra, Australia, 2 Department of Clinical Psychology and the EMGO Institute for Health and Care Research, Faculty of Psychology and Education, VU University Amsterdam, Amsterdam, the Netherlands Abstract Background: Many people with suicidal thoughts do not receive treatment. The Internet can be used to reach more people in need of support. Objective: To test the effectiveness of unguided online self-help to reduce suicidal thoughts. Method: 236 adults with mild to moderate suicidal thoughts were randomised to the intervention (n = 116) or a waitlist control group (n = 120). Assessments took place at baseline, and 2, 4 and 6 weeks later. Primary outcome was suicidal thoughts. Secondary outcomes were depressive symptoms, anxiety, hopelessness, worry, and health status. Results: The intervention group showed a small significant effect in reducing suicidal thoughts (d = 0.28). Effects were more pronounced for those with a history of repeated suicide attempts. There was also a significant reduction in worry (d = 0.33). All other secondary outcomes showed small but non-significant improvements. Conclusions: Although effect sizes were small, the reach of the internet could enable this intervention to help many people reduce their suicidal thoughts. Trial Registration: Netherlands Trial Register NTR1689 Citation: van Spijker BAJ, van Straten A, Kerkhof AJFM (2014) Effectiveness of Online Self-Help for Suicidal Thoughts: Results of a Randomised Controlled Trial. PLoS ONE 9(2): e90118. doi:10.1371/journal.pone.0090118 Editor: Hamid Reza Baradaran, Iran University of Medical Sciences, Iran (Republic of Islamic) Received September 8, 2013; Accepted January 24, 2014; Published February 27, 2014 Copyright: ß 2014 van Spijker et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This study was funded by the Netherlands Organisation for Health Research and Development (ZonMw), the Hague, project number 120510003. The funder had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: BvS, AK and AvS are authors of the web-based treatment program described in this manuscript. BvS and AK receive royalties from an adapted paper version of the self-help program described in this manuscript under the title ‘‘Piekeren over zelfdoding’’ (in Dutch), published by Boom: Amsterdam (2012). This does not alter the authors’ adherence to all the PLOS ONE policies on sharing data and materials. * E-mail: baj.van.spijker@gmail.com Introduction Although effective treatments exist [1], [2], [3], [4], [5], [6] 44% of suicidal people in high income countries do not receive treatment [7]. Barriers to seeking help include a preference for self-reliance, believing in spontaneous recovery, thinking the problem is not severe, believing that treatment will not be effective, fear of stigma, shame, and prejudice against, and/or negative experiences with, healthcare providers [7], [8]. Providing anonymous help online may address some of these obstacles [9], [10]. Moreover, people who receive mental health treatment could benefit from an additional online intervention [11]. The majority of people with suicidal thoughts meet criteria for a psychiatric disorder, most commonly depression and to a lesser extent anxiety [12], [13]. In addition, hopelessness has frequently been associated with suicidality [14], [15]. More recently, associations between worry and rumination and suicidal thoughts have been described. Specifically the repetitive character of suicidal thoughts shows similarities with worry and rumination [16], [17]. Web-based interventions have been found effective for a range of mental disorders, e.g. depression [18], [19], anxiety [18], [20], and problem drinking [21]. Most of these web-based interventions are based on Cognitive Behavioural Therapy (CBT), which is relatively easy to adapt to an (online) self-help format due to its structured approach. Evidence that online treatment can reduce suicidal ideation is now also emerging [22], [23]. This paper describes a randomised controlled trial (RCT) comparing unguid- ed web-based self-help for suicidal thoughts with a waitlist control group. It was hypothesised that the intervention would be better in reducing suicidal thoughts expecting a small effect size given previous findings that effect sizes for unguided self-help are generally modest and lower than those for guided self-help [19]. In addition, improvements were expected on all secondary outcomes (depression, hopelessness, worry, anxiety, and health status). Methods The protocol for this trial and supporting CONSORT checklist are available as supporting information; see Protocol S1 and Checklist S1. PLOS ONE | www.plosone.org 1 February 2014 | Volume 9 | Issue 2 | e90118