Study design
Depressive Symptomatology-Self
REGRESSION, BLOOD
Eligible participants were scheduled to receive an intervention within 25 days of completing screening. Between screening and baseline assessment, participants completed the Inventory of Depressive Symptomatology-Self Report (IDS-SR) at home an average [standard deviation, (SD)] of 8.28 [4.17] days after screening. Participants showing a ≥30% reduction from their IDS-SR score at screening were considered likely responders to non-specific aspects of study enrollment or as demonstrating regression to the mean/spontaneous recovery and were discontinued from the study. On the intervention day, participants arrived at the medical center at 8 AM and completed a baseline assessment that included the HDRS and a blood draw. The study intervention commenced between noon and 1 PM. On completion of the intervention, participants rested for 1 h and were released to home. Follow-up HDRS assessments were conducted at post-intervention weeks 1, 2, 4, and 6. Blood was withdrawn at 8:30 AM prior to receiving a study intervention, immediately (within 30 min) upon completion of the study intervention, and at 1- and 4-weeks post-intervention. With the exception of the immediate post-treatment blood draw, blood was collected between 8:30 AM and 9:30 AM to control for potential circadian variation in plasma cytokine concentrations.