Feasibility and engagement of smartphone delivered yoga imagery with or without personalized avatars in residential substance use treatment: The AT-REACH nonrandomized pilot

Background. Brief guided imagery may provide a practical way to rehearse a yoga experience between live sessions. We evaluated smartphone delivery and repeated use of yoga imagery and explored whether adding a personalized animated avatar was associated with different outcomes. Methods. This nonrandomized pilot enrolled 35 adults in four cohorts at residential substance use recovery facilities in Nebraska. Participants received an introductory yoga session and brief app delivered imagery practices, with three daily prompts. Thirteen participants received imagery with an animated avatar and 22 received imagery without the avatar. Allocation was by seat choice rather than a randomized sequence; the fourth cohort received the comparison condition only. We summarized app use over the first 28 days of logs, rated emotion changes around practice, and baseline to exit questionnaire outcomes. Results. All 35 initiated the app and 27 (77%) completed the exit assessment. Participants logged 2901 sessions, a median of 86 per person (interquartile range 62 to 104). At least three sessions were logged on 59% of days and at least one on 68%. The between group engagement effect was close to zero but imprecise (Hedges g = 0.03, 95% CI -0.66 to 0.71). Mean negative emotion intensity changed by -8.9 points on a 0 to 100 scale (95% CI -15.9 to -1.9). The baseline adjusted DERS total difference was 9.2 points (95% CI -6.7 to 25.2). The exploratory DERS Awareness change effect favored animated visual support (g = 0.89, 95% CI 0.06 to 1.73), but the cohort adjusted exit difference was smaller and imprecise (-1.30 points, 95% CI -5.05 to 2.46). Other questionnaire findings were mixed. Conclusions. The pilot documents repeated use of brief guided yoga imagery in residential recovery settings. It does not establish imagery efficacy, equivalence between formats, or an added benefit of animated visual support. Randomized evaluation with consistent assessment and complete delivery logs is warranted.