Longevity & AgingInsomnia Makes Older Adults 3x More Vulnerable to Inflammation-Triggered Depression
A UCLA-led randomized clinical trial of 160 adults aged 60+ found that endotoxin-induced inflammation triggered three times greater increases in depressive mood in those with insomnia versus those without. Using low-dose endotoxin (0.8 ng/kg) to experimentally mimic inflammatory exposure, researchers found that insomnia amplified both self-rated and observer-rated depressive symptoms, with effects persisting longer in the insomnia group. Crucially, both groups showed similar inflammatory cytokine responses, suggesting insomnia heightens neural or behavioral sensitivity to inflammation rather than amplifying the inflammatory signal itself. The findings establish a mechanistic link between insomnia, inflammation, and late-life depression, arguing for targeted depression prevention strategies in older adults with sleep disorders.
