Tucson Standard

An analysis conducted by researchers at the University of Arizona College of Medicine – Tucson's Department of Psychiatry has highlighted a significant link between disrupted sleep and increased risks for suicide and homicide. The study found that nearly 19% of suicides and 36% of homicides occur during nighttime hours, with factors such as nocturnal wakefulness, age, alcohol use, and relationship conflicts playing a crucial role.

Lead author Dr. Andrew Tubbs from the Sleep and Health Research Program stated, "Disrupted sleep may acutely impair rational thought, which can drive impulsive behaviors in vulnerable individuals." The research analyzed data spanning 15 years across the United States, revealing a fivefold increase in suicide risk and an eightfold increase in homicide risk between 2 a.m. and 3 a.m., after adjusting for the number of people awake.

The study titled "Risk for Suicide and Homicide Peaks at Night: Findings From the National Violent Death Reporting System, 35 States, 2003–2017," was published on May 29 in the Journal of Clinical Psychiatry.

Michael Grandner, senior author of the study and an associate professor of psychiatry at UArizona College of Medicine – Tucson noted that "the fact that these overnight risk patterns apply to both suicide and homicide is striking." He explained that their review covered over 78,000 suicides and 50,000 homicides to gain insights into why nocturnal wakefulness poses such risks.

The authors introduced the "mind after midnight" hypothesis suggesting that being awake during nighttime impairs decision-making functions while negative moods peak. This results in distorted risk/reward processing. Their findings indicated higher nighttime risks among adolescents, young adults, those intoxicated with alcohol or experiencing partner conflict. However, this was not observed among cannabis users or those suffering from depression.

Dr. Tubbs remarked on the need for further studies saying, "Few studies have examined time-of-day trends in violent crime." He suggested future research could explore brain activity predisposing individuals to these risks and whether improving sleep could mitigate them.

This article first appeared on the UArizona Health Sciences website.