Vu, AnnaMarie2020-10-262020-10-262018-08https://hdl.handle.net/11299/216811University of Minnesota Ph.D. dissertation. August 2018. Major: Psychology. Advisor: Patricia Frazier. 1 computer file (PDF); vii, 98 pages.mHealth smartphone apps have inundated the market. The promise of mHealth apps is that they increase access to psychotherapeutic content while also expanding options beyond face-to-face care. However, information on the quality and efficacy of commercial mHealth apps is sparse. Pacifica, a Cognitive Behavioral Therapy and Mindfulness-based mHealth app, is one of the most popular and publicly endorsed apps on the market. An initial week long pilot study was performed to assess feasibility and acceptability of the Pacifica app and Pacifica Lite, an active control version of the app, in a group of college students (N = 41). Participants generally used the app as intended and rated the aesthetics and functionality positively. The subsequent efficacy study extended the intervention period, added a waitlist control group, and enrolled a greater number of participants. To the best of our knowledge, this study was the first randomized controlled trial designed to examine the feasibility and efficacy of a commercial mHealth app using a smartphone active control app as a comparison. Participants (N=420) were randomly assigned to one of three groups: 1) The Pacifica app that includes the psychotherapy-based components, 2) the active control app “Pacifica Lite” without psychotherapy-based components, and 3) waitlist control. The intervention period was 14 days over the final weeks of a college semester. Participants completed pretest and posttest measures of mental health symptoms and general well-being, state-based affect, perceived stress, and mindfulness prior to and following the intervention period. Regression models with baseline scores as moderators indicated there was an effect of the Pacifica intervention compared to the Waitlist control on negative affect and global mental health. The effect of intervention group on negative affect, global mental health, and perceived stress were all moderated by baseline scores, whereby participants who had higher baseline distress levels reported greater responses to the Pacifica intervention compared to being on the Waitlist. A measure of trait mindfulness showed significant between-group differences, with significantly higher scores in the Pacifica group compared to the waitlist control. There were no effects related to group at posttest for total or subscale scores for symptoms of depression, anxiety, positive state-affect, and mindfulness practice. Overall, the Pacifica app appeared feasible and usable over a high demand final exam period, was significantly more effective than Waitlist on some measures, but it was not significantly more effective than the active control on any measures. Pacifica and the majority of mHealth apps available are not designed as alternatives to face-to-face care but college counseling centers and healthcare systems may choose to include apps like Pacifica as additional resources.enactive controlCBTmHealthmindfulnesssmartphonestressThesis or Dissertation