"Intellect", a Mobile Health Application based on cognitive-behavioral therapy principles, improves Anxiety and Worry: A Randomized Controlled Trial with an Active Control and a 2-Week Follow-Up

Digital self-guided mobile health (mHealth) applications are cost-effective, accessible, and well-suited to improve mental health at scale. This randomized controlled trial (RCT) evaluated the effectiveness of a recently developed mHealth programme based on cognitive-behavioral therapy (CBT) principles in improving worry. We also examined psychological mindedness (PM) as a mediator by which app engagement is thought to improve outcomes. The intervention group completed a 2-week "Anxiety and Worry" programme with daily CBTinformed activities, while the active waitlist-control completed a matched 2-week mHealth programme on procrastination. Participants filled out the Generalized Anxiety Disorder (GAD7), Patient Health Questionnaire (PHQ-9), and Psychological Mindedness Scale (PMS) at baseline, post-intervention and 2-week follow-up. App engagement was measured at postintervention only. Both groups showed significant improvements on anxiety and depression scores from baseline to post-intervention, but no group differences were observed. From postintervention to follow-up, only the intervention group showed further improvements for anxiety levels. Higher engagement with the mHealth app reported lower anxiety at post-intervention, and this relationship was fully mediated by psychological mindedness. This study provides evidence that (a) engaging in a CBT mHealth App can effectively reduce anxiety and worry, and (b) Psychological mindedness is a potential pathway by which engaging with a mHealthapp improves worry. While overall effect sizes were small, at the population level, these can make significant contributions to public mental health.


Introduction
Objectives 154 This study aimed to evaluate the effectiveness of a recently developed mHealth application 155 ("Intellect") "Anxiety and Worry," compared to an active control condition ("Procrastination") 156 among young adults in a randomized controlled trial (RCT) with a 2-week follow-up. We 157 hypothesized that participants in the intervention group would experience significant decreases 158 in anxiety (primary outcome) and depression (secondary outcome) compared to the active 159 control condition. Based on Bakker and colleagues' (13,21,22) prior work, we also investigated 160 whether PM mediates the hypothesized relationship between engagement with the mHealth app 161 and improvements in anxiety and depression scores.   Table 4. CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted July 25, 2022.  205 This is a 14-day mHealth program that provides psychoeducation on the negative core beliefs 206 and/or thought patterns associated with anxiety and worry, as well as effective coping 207 mechanisms and problem-solving techniques. Each psychoeducation module is followed by short 208 writing exercises, and a few situational-task questions (see Table 1 for a program overview and 209 Table 3 for techniques utilized). This module structure allows participants to actively practice 210 utilizing the techniques they have learned. The 14-day mHealth program on Procrastination provides psychoeducation on the 214 procrastination cycle, the mental barriers that arise due to procrastination, and ways to tolerate 215 and overcome the discomfort. Participants engaged daily in either short situational-task 216 questions, short writing activities, or mindfulness activity. The structure and duration of the 217 Procrastination Programme (PP) is similar to that of the Anxiety and Worry programme (see 218   Table 2 for program overview and Table 3 for technique utilized). CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted July 25, 2022.   is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

(which was not certified by peer review)
The copyright holder for this preprint this version posted July 25, 2022. ; https://doi.org/10.1101/2022.07.25.22278034 doi: medRxiv preprint Generalized Anxiety Disorder (GAD-7) 264 Generalized Anxiety Disorder-7 (GAD-7) is a 7-item self-report instrument that measures 265 anxiety as a continuum (42)     CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

(which was not certified by peer review)
The copyright holder for this preprint this version posted July 25, 2022. Data screening included examining the data for incompleteness. Missing data from the post-299 intervention and follow-up assessment were replaced with data from the last completed 300 questionnaire to ensure data was analyzed as intention-to-treat (ITT).

302
All data were analyzed using IBM SPSS v.25. Preliminary data analyses included normality 303 testing and checking for univariate outliers. 2 outliers (i.e. +/-3SD from the mean) were excluded.

304
T-tests and chi-square tests examined baseline group differences.  The main analyses were performed on the whole ITT sample (n=309), with the respective 326 outcome measure at pre-intervention as covariates. The mediation analyses were performed on 327 the ITT sample who completed the AES scale (n=201). Eta squared partial (η 2 partial ≈ .01: small; 328 η 2 partial ≈ .06: medium; η 2 partial ≈ .14: large) was the effect size reported for all findings (51).     Table 5. CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

. Comparison of Group Effects for Anxiety and Depression at post-intervention (T1-T2) and follow-up (T2-T3)
Note: X not significant, ✓ significant (p<.05) However, only indirect effects via PM were found for Anxiety at post-intervention, but no 520 direct effects. One explanation could be that the unmeasured presence of a conflicting mediator 521 that ultimately cancels out the overall direct effect (52,65). This is highly probable, as the 522 current study did not measure Coping Self-Efficacy and Emotional Self-Awareness, two as its relation to motivation, rather than attentional avoidance, may have an effect in depression 546 reduction (37). This is supported by studies that found PM to be associated with higher 547 commitment and stronger involvement in therapy (28,70,71), which is suggestive of an 548 individual's motivation. Therefore, it is likely that an increase in PM influenced participants' 549 motivation levels, leading to incitements to produce new goals, thereby exerting a stronger  CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

558
Our study is not without limitations. First, no waitlist group was included. Although our main 559 objective was to assess whether the Anxiety and Worry programme is more effective than the 560 active control (Procrastination programme) in reducing anxiety and worry, including a passive 561 control would have yielded a clearer result pattern. Furthermore, we underestimated the 562 relevance of CBT techniques utilized in the Procrastination programme for worry outcomes and 563 thus did not expect that it would be as effective in reducing anxiety among young adults.

564
Alternatively, future studies may consider utilizing mHealth programmes that are not based on 565 CBT or based on different treatment modalities. Moreover, future studies may benefit from 566 including a more objective app engagement measure to limit its potential in acting as a third 567 variable when examining mHealth application's efficacy. intervention. Altogether, this study suggests that engagement with mHealth apps is related to 579 reduction in anxiety and depression. One mechanism involved in exerting this effect is the 580 app's ability to improve an individual's Psychological Mindedness. Higher engagement with 581 either mHealth application predicted improvements on anxiety and depression scores. Despite 582 . CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted July 25, 2022. ; https://doi.org/10.1101/2022.07.25.22278034 doi: medRxiv preprint small effect sizes observed, the practical implications of these cost-effective, highly accessible 583 mHealth applications can meaningfully impact public mental health at scale. The authors would like to thank the students for participating in the trial, the funding listed, and 587 the team at Intellect for adapting the application and providing support throughout the study.

736
. CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) The copyright holder for this preprint this version posted July 25, 2022. ; https://doi.org/10.1101/2022.07.25.22278034 doi: medRxiv preprint