Abstract
Mindfulness training (MT) has a demonstrated ability to reduce stress and improve affect, however, the time-burden and logistical demands associated with many MT interventions can significantly limit the feasibility and scalability of their implementation, particularly in time-pressured individuals. Further research is needed to better understand the feasibility and efficacy of existing approaches to reducing the time-burden of MT interventions. The aim of this dissertation is to evaluate a short-form mindfulness program (Study 1) and SAM (Studies 2 and 3) for affect and stress in time-pressured populations. Study 1 used a random-effect meta-analytic approach to evaluate the difference in standardized mean change between MBAT and control groups across five distinct cohorts. Study 2 assessed the feasibility, acceptability, and efficacy of a short-form SAM in a randomized controlled trial in Reserve Officers' Training Corps (ROTC) cadets (n = 44). Study 3 used an event-contingent sampling approach to evaluate the acute effects of mindfulness practice engagement within the participants in Study 2 who completed at least one mindfulness practice (n = 34). In Study 1, multivariate and random effects meta-analyses demonstrated small-yet-significant differences between MBAT and no-training control groups in standardized mean change (SMC) from T1 to T2 for stress (ΔSMC = -0.255), positive affect (ΔSMC = 0.324), and negative affect (ΔSMC = -0.209). Study 2 found that digitally-delivered SAM practices were feasible and acceptable in a time-pressured group of ROTC cadets. However, there was no evidence of longitudinal treatment effects for stress or affect (all p's > .21). Results from study 3 demonstrated that completing a 15-minute mindfulness practice led to significant acute improvements in stress (p < .001), positive affect (p < .001), negative affect (p = .002), and focus (p < .001). Findings from this program of research offer insights into the feasibility and efficacy of various approaches to reducing time-burden associated with MT in time-pressured groups.