Seniors With Insomnia More Vulnerable to Inflammatory Challenge-Induced Depression

MONDAY, July 21, 2025 (HealthDay News) — Older adults with insomnia are more vulnerable to depressive mood and symptoms in response to inflammatory exposure, according to a study published online July 16 in JAMA Psychiatry.

Michael R. Irwin, M.D., from the Jane and Terry Semel Institute for Neuroscience and Human Behavior at the University of California, Los Angeles, and colleagues examined whether inflammatory exposure induces greater increases in depressive mood and symptoms in older adults with insomnia disorder versus those without insomnia in a parallel-condition randomized clinical trial. The trial included 160 nondepressed adults aged 60 years or older (53 with insomnia disorder and 107 without insomnia). Participant groups were randomly assigned to two conditions: endotoxin (79 participants: 26 with insomnia and 53 controls) or placebo (81 participants: 27 with insomnia and 54 controls).

The researchers found that endotoxin induced increases in Profiles of Mood States depression subscale (POMS-D) to a significantly greater extent compared with placebo in those with insomnia versus control, with a similar effect seen for observer-rated POMS-D mood. In addition, there were clinically meaningful increases seen in observer-rated measures of depressive symptoms. In both groups, similar increases in inflammatory cytokines were induced by endotoxin. In moderation analyses, inflammatory response was associated with increases in POMS-D in the insomnia group but not the control group.

“Insomnia not only robs older adults of rest but also primes their immune system to make them uniquely vulnerable to depression when faced with inflammation,” Irwin said in a statement. “Treatments targeted at this inflammation-related depression may prevent depression and benefit these patients to improve their overall quality of life.”

Abstract/Full Text