Sleep and Healthy Aging Research on Depression (SHARE-D) randomized controlled trial: Protocol overview of an experimental model of depression with insomnia, inflammation, and affect mechanisms in older adults

A randomized, placebo-controlled, double-blinded mechanistic clinical trial using endotoxin to evaluate the relationship between insomnia, inflammation, and affective disturbance on pain in older adults: A protocol for the sleep and Healthy Aging Research for pain (SHARE-P) study

“…Randomization to endotoxin or placebo conditions was completed by RO (study biostatistician) who did not interact with study participants. More information about randomization is detailed in the parent study protocol ( Irwin et al, 2023 ). Approximately one third of the sample were predicted to meet criteria for insomnia disorder using the Structured Clinical Interview for DSM-5 ( First et al, 2014 ), with the remaining participants having no current insomnia disorder.…”

“…Participants were required to be enrolled in the UCLA SHARE-D study ( Irwin et al, 2023 ) to be considered for the current study (SHARE-P). Participants were excluded if: they scored ≥ 2 on the Graded Chronic Pain Scale ( Von Korff et al, 1992 ); had a chronic pain disorder diagnosis (except for osteoarthritis, which is prevalent in older adults and its exclusion would reduce generalizability of findings); or had Raynaud's Syndrome (as symptoms could be exacerbated by the cold pressor test).…”

“…The current study added to the study procedures detailed in SHARE-D ( Irwin et al, 2023 ) in four ways: (1) adding pain assessments to the parent study's baseline visit, (2) including an orientation session for quantitative sensory testing, (3) adding quantitative sensory testing starting ∼5hrs post endotoxin/saline injection, and (4) including longitudinal assessments of sleep, pain, and depressive symptoms at baseline, 3, 6, 9, and 12 months following the experimental portion of the study. The specific modifications are detailed below, organized by study visit.…”

“…A quantitative sensory testing battery was added to the parent project's experimental study visit (see Fig. 2 ; Irwin et al, 2023 ). Briefly, participants reported to the laboratory at approximately 8am.…”

“…Participants completed hourly surveys to assess mood (self-reported Profile of Mood States; POMS; McNair, Lorr, & Droppleman, 1992 ). Blood samples were collected every 30min for the first 2 h and then every hour until 12 hours post-injection to assess inflammatory cytokines, including IL-6, TNF, IL-8, and IL-10; Irwin et al (2023) . Quantitative sensory testing was initiated ∼5.5 hours post-injection, with the entire procedures lasting 60–90min.…”