Several recent studies have used real-time monitoring to provide information about several basic characteristics of suicidal thinking. First, the severity of suicidal ideation varies considerably over a short period of time. Two studies showed that there is nearly as much variability in reports of suicidal ideation from hour to hour as there is from person to person [4,9]. Second, episodes of suicidal ideation have a quick onset, with nearly onethird of all observations in one study differing by a standard deviation or more from the prior rating just a few hours earlier [4]. Third, episodes of suicidal ideation tend to be brief, with participants reporting most episodes are shorter than an hour [10]. Fourth, thoughts of suicide are distinct from thoughts of nonsuicidal selfinjury (NSSI), and co-occur less than half the time, even among those who frequently engage in NSSI [10].