Nocturnal wakefulness closely associated with higher suicide rates: Study

Australia: Nocturnal wakefulness may be a recognized risk factor in triggering suicide events overnight, says an article published in the Journal of Clinical Psychiatry.

Prior research on suicide patterns over a 24-hour period has yielded conflicting results. Analyses of 24-hour temporal patterns for wakeful acts, including suicidal conduct, should, however, account for expected sleep requirements, which skew such activities to traditional wakeful periods. As a result, Darren R. Mansfield and colleagues undertook this study to examine the time of day for suicide cases in the Australian population in 2017, controlling for expected sleep patterns. Using this methodology to identify time-of-day trends may reveal risk factors for suicide as well as possibly adjustable contributions.

For this study, The Australian National Coronial Information System database was examined, and statistics regarding completed suicides for the most recently completed year were extracted (2017). The time of suicide was assigned to one of four 6-hourly time bins spread across 24 hours, defined by the time last seen alive and the time found afterward. Suicide prevalence was adjusted for the likelihood of being awake each time bin using sleep-wake norms from a large Australian community survey. The observed prevalence of suicide as compared to expected values is estimated as a normalized incidence ratio from the likelihood of being awake throughout each time bin (SIR).

The key findings of this study were as follows:

1. In 2017, there were 2,808 suicides, 1,417 of which could be assigned to one of four 6-hourly time bins.

2. Suicides were substantially more likely to occur in the overnight bin when compared to predicted values (2301-0500; SIR = 3.93).

In conclusion, The findings of this study highlight the demand for further intense research to better understand the causative elements underlying the link between nighttime wakefulness and suicide risk.

Reference: Mansfield, D. R., Wasgewatta, S., Reynolds, A., Grandner, M. A., Tubbs, A. S., King, K., Johnson, M., Mascaro, L., Durukan, M., Paul, E., Drummond, S. P. A., & Perlis, M. L. (2022). Nocturnal Wakefulness and Suicide Risk in the Australian Population. In The Journal of Clinical Psychiatry (Vol. 83, Issue 4). Physicians Postgraduate Press, Inc. https://doi.org/10.4088/jcp.21m14275