FIGURE 1.

The prevalence and risk for suicide across 24 h. Although most suicides (grey bars, representing % of maximum hourly suicide count) occur around noon, population wakefulness (light grey shaded area) is also maximal at this time and throughout the afternoon and evening. After adjusting for population wakefulness, the incident risk ratio of suicide is substantially increased at night (black line, 95% confidence interval represented by dark grey band), with a 4.25-fold greater risk at 2AM than the 24-h average. Data are derived from the American Time Use Survey and the National Violent Death Reporting System for 2003 to 2010. Data are double-plotted to improve visualization of increased risk during nighttime hours.