A new study published in an online supplement to the journal Sleep has determined that there is a higher likelihood of suicide in the hours between midnight and 4:00 a.m. then at any other time of day or night. The first-of-its-kind data analysis negates previous understands of when suicide was happening in proportion to the number of people actually awake, and gives a much more realistic accounting of some possible causes and mechanisms of these fatal incidents.
Suicide accounts for roughly 38,000 deaths in the United States each year, far more than double the number attributable to homicide. The data revealed in the study points to the very real possibility that if people receive treatment for insomnia, the rate of suicide could fall substantially.
The study was conducted by researchers from the Penn Behavioral Sleep Medicine Program at the University of Pennsylvania in Philadelphia. By breaking down suicide rates into the number of suicides per hour in six-hour blocks, the team found that the rate was 10.27 percent after midnight, with the highest number occurring between 2:00 a.m. and 2:59 a.m. By contrast, the suicide rate per hour in the morning hours between 6:00 a.m. and noon was 2.13 percent, and the six-hour period preceding that time block was 3.6 times higher than would be expected based upon the number of people anticipated to be awake.
According to principal investigator and associate professor in the Department of Psychiatry Michael Perlis, PhD, “This appears to be the first data to suggest that circadian factors may contribute to suicidality and help explain why insomnia is also a risk factor for suicidal ideation and behavior. These results suggest that not only are nightmares and insomnia significant risk factors for suicidal ideation and behavior, but just being awake at night may in and of itself be a risk factor for suicide.”
Though previous research had implied that a larger percentage of suicides generally occur during the day, those studies had not accounted for the fact that greater numbers of people are awake during the day then are at night. By taking the numbers of suicides that occurred during each block of time and controlling them for the percentage of the population that is awake at each given hours, the statistics changed dramatically. The team utilized historical data that had been collected within the National Violent Death Reporting System, which collects information regarding the time that a violent death occurs, as well as the American Time Use Survey, which answers the question about how many Americans are generally awake at any given time. The total number of suicides that were studied by the researchers within this framework exceeded 35,000.
With the American Academy of Sleep Medicine indicating that approximately one in ten American adults suffer from some kind of chronic sleep problem extending for a