Firefighter Study Links Insomnia and Depression

Insomnia and nightmares appear to influence depression symptoms specifically through the pathway of explicit emotion regulation difficulties.

Study results published in the February 15, 2016, issue of the Journal of Clinical Sleep Medicine indicate that insomnia and nightmares appear to influence depression symptoms specifically through the pathway of explicit emotion regulation difficulties. “Sleep disturbances may impair the ability to access and leverage emotion regulation strategies effectively, thus conferring risk for negative affect and depression,” wrote the authors.

The study included an Internet-based survey of 880 current and retired United States firefighters, aged 18 to 82 years, who answered questions regarding behavioral health. Self-report measures included the Center for Epidemiologic Studies Depression Scale, Insomnia Severity Index, PTSD Checklist, and Difficulties in Emotion Regulation Scale.

Nearly 40% of participants reported clinically significant depression symptoms, more than one-half reported insomnia symptoms, and about 20% reported nightmare problems, all of which demonstrated a strong association with emotion regulation difficulties. Bootstrapped mediation analyses showed that the indirect effects of overall emotion regulation difficulties were significant for the association between insomnia and depression as well as between nightmares and depression. Limited access to problem-solving skills, the ability to decrease negative emotions, and other emotion regulation strategies emerged as the strongest, most significant indirect effect for both associations.

“Our study findings suggest that firefighters with sleep difficulties are likely to experience greater struggles accessing strategies to regulate their emotions, especially when feeling upset. This, in turn, may lead to or worsen feelings of depression and low mood,” said lead author Melanie Hom, MS, a doctoral candidate in the Laboratory for the Study and Prevention of Suicide-Related Conditions and Behaviors within the Department of Psychology at Florida State University.

“These results are important because they provide a plausible explanation for why and how sleep problems may contribute to depression, which are critical questions for prevention and intervention," Hom said.

The findings may shed some light on approaches to treating the estimated 30% to 35% of people in the United States with transient insomnia symptoms—according to the American Academy of Sleep Medicine—as well as the 10% of adults affected by chronic insomnia (occurring at least three times weekly for at least 3 months) and the 2% to 8% of the general population who have a current problem with nightmares. The study results maybe also be encouraging to those with trauma-related nightmares, the most consistent problem reported by people with PTSD.

“Firefighters are typically faced with many demands, including difficult work schedules, and they often both witness and experience traumatic events,” said Hom. “It is not surprising that firefighters may experience sleep problems and depression, but it is critical that greater efforts be made to prevent and treat these problems.” She and her co-authors suggest that emotion dysregulation may be an important therapeutic target for reducing depression risk among firefighters and others who experience insomnia and nightmares.