A study shows that insomnia symptoms mediate the relationship between alcohol use and suicide risk, and that this mediation is moderated by gender. The study suggests that the targeted assessment and treatment of specific sleep problems may reduce the risk of suicide among those who use alcohol.

The study found that alcohol use was significantly associated with suicide risk among women. However, further analysis revealed that insomnia symptoms explained a significant proportion of the relationship between alcohol and suicide risk. For men, there was no direct effect of alcohol use on suicide risk, but there was a significant indirect effect of alcohol use increasing suicide risk through insomnia symptoms.

“These results are important as they help demonstrate that alcohol use is associated with an increase in suicide risk, and that this increase may be partially due to insomnia symptoms,” says principal investigator Michael Nadorff, PhD, assistant professor at Mississippi State University, Starkville, in a release. “By better understanding this relationship, and the mechanisms associated with increased risk, we can better design interventions to reduce suicide risk.”

Although the design of this study did not allow for an examination of causality, the present study lays the groundwork for future longitudinal investigations that further elucidate the relationship among alcohol use, insomnia symptoms, and suicide risk.

Study results are published in the December issue of the Journal of Clinical Sleep Medicine.

According to the American Academy of Sleep Medicine, about 10% of people have chronic insomnia disorder, which involves a sleep disturbance and associated daytime symptoms that have been present for at least 3 months. About 15% to 20% of adults have short-term insomnia disorder. Both types of insomnia are more common in women than in men.

The study involved 375 undergraduate students at a large, public university in the southeastern United States. They completed an online questionnaire that examined insomnia symptoms, nightmares, alcohol use, and suicide risk.

The Centers for Disease Control and Prevention reports that excessive alcohol use leads to about 88,000 deaths in the United States each year and shortens the life of those who die by almost 30 years. Accounting for more than 38,000 deaths each year, suicide is the 10th leading cause of death in the United States, according to the CDC.