The purpose of the introductory part is to think about its necessity and significance before we go into full-scale gatekeeper training. This part is mainly composed of Lecture Overview, Introductory Video, Comparison between Suicide and Traffic Accidents, Unknown Suicides, and Necessity of Gatekeeper Program. In the “Introductory Video”, the current impact of suicide in Korea is introduced, and it is taught that many suicides are preventable. In “Comparison between Suicide and Traffic Accidents,” the changes in suicide deaths and traffic accident deaths over the past few decades were compared to each other. Traffic accident deaths have fallen to about one-third for about 20 years thanks to a steady investment by the Korean government, while suicide deaths have nearly doubled for the same period. The authors suggested that public interest, social awareness, systematic planning, and sufficient investment can lead to good results through comparisons of traffic accident deaths and suicide deaths. “Unknown Suicides” refers to suicides that are not reflected in statistical figures. In this section, it is suggested that there are 5% of the entire population with the cases in which even if it is not counted as official suicide, it can be said to be actual suicide. It is also emphasized that suicide is never a rare or of little important event in our society. Lastly, the “Necessity of Gatekeeper Program” includes that the World Health Organization and the US Centers for Disease Control and Prevention recognize the gatekeeper program as an effective intervention strategy for suicide prevention.

In the ‘Careful observation’ part, we deal with detecting signals from high-risk people at suicide. This part consists of eight parts (Table 1). The contents of this part were updated largely through the active use of the results of the ‘2018 Psychological Autopsy Interview’ by the Central Psychological Autopsy Center. The resources provided by the Central Psychological Autopsy Center made it possible to reflect as much of the danger signals that real suicide victims have shown in their lives. The first section, “Three Examples,” show situational and behavioral signals of suicides that those around people at risk for suicides may have perceived while they were alive. This section can remind us of the importance of timely perception of danger signals that suggest suicide. The “Undetected Suicide Signal” shows how suicide risk signals were not correctly detected in the real world by suggesting that the suicide victims expressed 92% suicide risk signals, but 77% of people around the suicide victims did not notice the signals. The “The Process of Reaching Suicide” section shows three stages of suicide, which are suicide thought, a suicide plan, and suicide attempt. The “Linguistic Signals” visually show the danger signals that suicide victims showed most in their lives: expressions of death including suicide, physical discomfort, and selfdeprecating words. In addition, suicide risk signals such as posting death-related content on social media, interest in the afterlife, and expressions of suicide are frequently presented. The “Behavioral Signals” show various behaviors of suicidal deaths including changes in emotions and behaviors before death, depressive symptoms, settling affairs before death, and death-related behaviors. In particular, the situation in which urgent intervention is needed was emphasized by highlighting the dangerous behaviors of suicides when suicides are imminent, such as three months or one week before suicide. The “Situational Signals” shows the situational difficulties suicide victims experienced during their lifetime, including mental health, work, economics, and family-related problems. In particular, the age group is divided into the young, the middleaged, and the elderly, respectively, and high-risk situational signals for the corresponding age group are presented. For example, academic and interpersonal issues such as study and date in the young, economic problems such as debt in the middle-aged, and chronic illness & physical symptoms in the elderly are presented as dangerous situations. In the “Video,” the examples of young people are adapted and the scenario is composed. In the last section, “What Should We Do After Careful Observation?,” we take time to think about how the surrounding people should have responded after watching the video with the bad ending. Throughout this section, trainees are motivated to learn the next step, ‘Active listening.’

Listening consists of nine parts (Table 2). First of all, the first “Video” shows linguistic, behavioral, and situational signals suggesting suicide from a self-employed middle-aged man. This video shows a surrounding person who fails to empathize with a person at risk of suicide. The surrounding person consequently fails to engage in suicide prevention intervention as a result of speaking and acting only according to his or her thoughts and judgments. This makes trainees think about how to respond initially to suicide high-risk group people. In the “Question 1 for listening: Do you think about suicide?,” based on evidence-based research results, it emphasizes that trainees directly ask about suicide and asks a question about it because referring to suicide does not increase the danger of suicide, but rather helps to prevent it. The “The Listener’s Mind” deals with various emotions that arise when it is directly confirmed that a person is thinking about suicide. The “Unhelpful Listening” shows that helpful interventions cannot be made if the listeners follow only their own emotions, not those of people at risk of suicide. In the “Question 2 for Listening: Why did you think about suicide?” We show that sympathizing with the minds of people at risk of suicide, not the listener’s mind, is the most basic mindset. We show that sympathizing with people at risk of suicide begins by asking why they thought they should commit suicide. The “Listening Skill: Active Listening” shows how to create an atmosphere at which people at risk of suicide can comfortably tell his story through sympathetic listening and a non-judgmental attitude. The “The Response of Gatekeeper” is a section that trainees can practice the skills acquired in the “Listening” section. Intervention can be practiced naturally by the trainees actually doing the expressions such as “You were so hard that you wanted to die.,” “It must have been a tough situation for you to tell the story, but thank you for telling me.” The “Ambivalence” makes trainees know that someone who thinks of suicide also has a desire to live. The last section, “The Reason to Live,” shows that people at risk of suicide can identify the reasons why they should live.

The ‘Risk evaluation and Expert referral’ consists of nine parts (Table 3). The first part, “Video 3,” comprehensively shows the situational, behavioral, and linguistic signals of people at risk of suicide. The “Checking Suicide Risk” teaches questions accurately identifying suicide plans, methods, and prior suicide attempts. The “Helping safely” shows how to secure safety for people at risk of suicide. For example, it includes not recommending alcohol to people at risk of suicide. In the “Understanding Depression,” we introduce mental illnesses such as depression and explain the symptoms. In the “Piece Together a Puzzle of Hope,” we introduce people, institutions, and services that people at risk of suicide can call or use for help. In the “Core Contacts,” we introduce Korea’s representative suicide prevention services (e.g., 24-hour suicide prevention hotline 1577-0199). The “Good Ending” shows a finale that a selfemployed middle-aged man who was once at risk of suicide was referred to appropriate suicide prevention service without acting suicide attempt. The good finales could be accomplished by making good use of all the skills trainees have learned. In the “Role Play,” trainees do a role play based on the “Good Ending” script. In “Arrangement,” the core contents of the ‘Suicide CARE’ are arranged and presented.