The purpose of the “Introduction” section is to establish the necessity and importance of gatekeeper training for suicide prevention. This section includes the following: an overview of “Suicide CARE for NKDs,” the introduction video, “comparing suicide statistics and traffic accident statistics,” “introduction of Suicide CARE for NKDs,” and “necessity of gatekeeper programs.” In the introduction video, several questions are presented to encourage trainees to consider the mental states of those who die by suicide, and they are provided with basic suicide prevention education. In “comparing suicide statistics and traffic accident statistics,” trainees learn that 13,799 people died by suicide in South Korea in 2019, 4.1 times higher than the number of traffic accident deaths, which was 3,349. They learn that an average of 37.5 people per day die from suicide in South Korea. Trainers explain that improving social awareness through suicide prevention campaigns, reinforcing accessibility through support for medical expenses and expansion of mental health promotion facilities, and gatekeeper training can lead to a reduced suicide rate. In the “introduction of Suicide CARE for NKDs,” trainees learn that this is the first suicide prevention education program for NKDs. Finally, the “necessity of gatekeeper programs” includes teaching trainees that, according to an analysis of the effectiveness of South Korea’s “Suicide CARE” gatekeeper program, 20% of trained gatekeepers have met someone at risk of suicide, 95% have asked someone about suicide and listened to their replies, and 71.5% have provided helpful information and connections to experts. The trainers emphasize the necessity and importance of gatekeeper education for suicide prevention.

In “Careful observation,” gatekeepers are taught to see and recognize signals indicative of high-risk suicide situations. It comprises eight subsections (Table 1). First, “introduction to careful observation,” discusses the importance of recognizing signals of suicide risk, being interested in the at-risk person, and being ready to approach them. “Undetected suicide signals” emphasizes how important it is to pay attention and recognize suicide risk signals in high-risk groups. According to a 2018 report from Korea Psychological Autopsy Center, 92% of those who die by suicide expressed suicide risk signals when they were alive. However, 77% of those around them were unaware of these signals. “The process of reaching suicide” shows trainees the three stages of suicide: suicidal thoughts, suicide plan, and suicide attempt. They learn the importance of recognizing and intervening for high-risk factors during the suicidal thoughts or plan stages, before suicide is actively attempted. “Linguistic signals” visually shows the danger signals most often presented by people who ultimately died by suicide—primarily, talk of death such as suicide, complaints of physical discomfort, and self-deprecating language. In addition, suicide risk signals such as expressing a desire to be dead (e.g., in letters, notes, and social media posts), asking how to die by suicide, talking about people who have died by suicide, and admiring the afterlife are described. In particular, it is emphasized that talk of death and complaints of physical discomfort are characteristic linguistic signals for NKDs. The “behavioral signals” subsection alert trainees to unusual behavioral signals commonly preceding suicide deaths among NKDs, including changes in aggressive/impulsive behavior, signs of self-harm, preparatory acts, emotional changes, sudden alcohol or drug abuse, and depressive symptoms. Mental and physical health problems, job-related problems, and economic problems are important situational difficulties reported in NKDs who died by suicide. In the next subsection, a video is used to present the case of a female NKD who had been in South Korea for five years who died by suicide. After watching the video, including the bad ending, the last subsection, “what should we do?,” is presented. Trainees are given time to think about how the people around the female in the video should have responded.

“Active listening” consists of nine subsections (Table 2). The first, “introduction to active listening” briefly introduces this section to trainees. “Asking about suicidal thoughts” emphasizes that trainees should directly ask other NKDs about suicide. This section was developed using evidence-based research. Asking someone about suicidal thoughts does not increase their risk of suicide, but it may offer them some relief if they are having suicidal thoughts. Thus, it is important to directly ask NKDs if they have been having suicidal thoughts. “The listener’s mind” deals with a variety of emotions, such as shock and a desire to avoid, that are experienced by gatekeepers who confirm that another NKD has a suicidal intention. “Unhelpful listening” teaches trainees that it is most helpful to follow the emotions of a person at risk of suicide while listening to them rather than reacting to the emotions the story evokes in oneself. This subsection also emphasizes that human life and safety are more important than confidentiality. “Helpful listening” shows that to listen and accept the heart of a person with suicidal thoughts is the most basic mindset gatekeepers need. Trainers show them that empathizing with people at risk of suicide begins with asking them why they think they should attempt suicide. “Listening skill: active listening” demonstrates how to create a comfortable atmosphere in which high-risk people can tell their stories honestly and how to listen to their stories through empathetic listening with a non-judgmental attitude. “Empathetic response” teaches trainees how to improve their active listening skills so that these skills can be applied in practice. Trainees pair up and practice empathetic responses, such as “If you have ever contemplated suicide, you must have been going through lots of hard time,” “I’m sorry for not being able to help you because I didn’t know you were so heartbroken,” and “Thank you very much for telling a story that is difficult to tell honestly.” “Ambivalence” helps trainees understand that people who consider attempting suicide may also have the desire to live. Finally, “asking about the meaning of life” explains that asking the right questions can remind people of the importance of their lives.

“Risk evaluation and expert referral” consists of nine subsections (Table 3). First, “video on risk evaluation and expert referral,” comprehensively shows the situational, behavioral, and linguistic signals of people at risk of suicide. In “checking for suicide risk,” trainees are taught what questions to use to identify suicide plans, suicide methods, and a history of suicide attempts. “Helping safely” shows how to secure the safety of people at risk of suicide, such as not leaving them alone and recommending they do not drink alcohol. “Understanding depression” introduces mental health disorders, including depression, and explains the symptoms. “Piece together a puzzle of hope” introduces people, institutions, and services that people at risk of suicide can look to for help. “Key contacts” discusses South Korea’s representative suicide prevention services (e.g., 24-hour suicide prevention hotline 1577- 0199) and the regional Hanacenter. The “good ending” focuses on a middle-aged female NKD at risk of suicide who receives help from acquaintances after she asks them about suicide, and they empathetically and actively listen to her story. Further, she is referred to the appropriate suicide prevention service before she makes a suicide attempt. It is emphasized that a good ending can be accomplished by making use of all the skills the trainee has learned. In “role play,” trainees act out a scene based on the “good ending” script. In “wrap-up,” the core content of the program is summarized and completed.