2.1. Eligibility Criteria and Randomized Trial Design
In this study, we recruited healthy young adult participants aged 18–35 years. We excluded participants with (1) an active infection/disease, (2) a current untreated mental or physical health condition deemed likely to interfere with their ability to complete the study procedures (determined by study staff consensus), (3) current use of medications with known effects on stress physiology, including antidepressants (SSRI, SNSI, NDRI, atypical, TCA, MAOI), antipsychotics, benzodiazepines, non-benzodiazepine receptor agonists, melatonin and melatonin receptor agonists, orexin/hypocretin receptor antagonists, barbiturates, mood stabilizers, anticonvulsants, anticholinergics, first generation antihistamines, and stimulants including NRI, antihypertensives, opioids, or systemic corticosteroids, (4) current pregnancy, and (5) moderate/substantial prior meditation, yoga, or other mind-body practice reported as a self-rating of 5 or higher on a scale of 0–10 asking “How experienced are you with meditation, yoga, or other mind-body interventions?”. 