Suicide risk significantly elevated at night
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Suicide risk is higher at night than any other time of day, according to a study published in Journal of Clinical Psychiatry. Researchers found no significant variation in this risk by method, month or demographic characteristics.
“Nighttime involves an increased risk for suicide that simply isn't present at other times of day,” Andrew S. Tubbs, BSc, graduate research associate of the department of psychiatry at University of Arizona, told Healio Psychiatry. “Therefore, increasing suicide prevention efforts during the night (eg, 2-3 a.m.) may help save lives. Additionally, treating conditions that increase wakefulness at night (eg, insomnia, sleep apnea) may indirectly reduce suicide risk by helping people sleep through this high risk time.”
According to the researchers, insomnia is a risk factor for suicide, and after accounting for population wakefulness, the risk for suicide is disproportionately highest at night. To investigate whether this risk varies across methods of suicide and/or months, Tubbs and colleagues collected time, date, method and demographic information for 35,338 suicides included in the National Violent Death Reporting System between 2003 and 2010. They compared the estimated hourly proportion of the population awake from the American Time Use Survey for 2003 to 2010 with the time of fatal injury, which was grouped into 1-hour bins. After generating hourly incidence risk ratios (IRRs) for suicide using negative binomial modeling, they aggregated risks into four categories — morning (6 a.m. to 11:59 a.m.), afternoon (noon to 5:59 p.m.), evening (6 p.m. to 11:59 p.m.) and night (midnight to 5:59 a.m.).
Results showed that across all months and methods, risk for suicide was higher at night (P, .001). The mean nocturnal IRR across months was 3.18 (standard deviation [SD], 0.314), with the lowest IRR in November (2.74) and the highest in May (3.9). Across methods, the mean nocturnal IRR was 3.09 (SD = 0.472), with the lowest IRR for drowning (2.44) and the highest for fire (3.75). Nocturnal risk was elevated within all demographics (P < .001 for all); however, there were no method-by-time or month-by-time interactions across demographics.
"No matter the month or method, more suicides happen at night than any other time of day," Tubbs said. “My interpretation is that, whether it's January or July, being awake when your brain is not thinking clearly increases risk for suicide.” – by Joe Gramigna
Disclosures: The authors report no relevant financial disclosures.