Evaluation of a Transdiagnostic Mobile App Intervention Among University Students

Perceived Stress Scale (PSS-10) is used to evaluate participants' stress levels. Participants are asked to specify how often they felt or thought a certain way over the last month on a scale from 0 [never] to 5 [very often]. The score ranges from 0 - 40, with higher scores indicating higher levels of perceived stress symptoms.

The Emotion Regulation Skills Questionnaire (ERSQ) will be used to assess emotion regulation skills. This instrument includes seven distinct emotion regulation skills: awareness, sensation, clarity, understanding, acceptance, tolerance, compassionate self-support, confrontation readiness, and modification of negative emotions. It consists of 27 items, each scored on a scale ranging from 0 (not at all) to 4 (almost always). Higher scores on both the ERSQ subscales and the aggregate ERSQ score are indicative of higher emotion regulation skills.

Depressive symptoms are measured with the Patient Health Questionnaire (PHQ-9). Participants are asked to indicate how often they have been bothered by a certain symptom over the past two weeks on a scale from 0 (not at all) to 3 (nearly every day). PHQ-9 scores range from 0-27. Higher scores indicate higher levels of depressive symptoms.

Anxiety symptoms are measured with the Generalized Anxiety Disorder (GAD-7) questionnaire. Participants are asked to indicate how often they have been bothered by a certain symptom over the last two weeks on a scale from 0 (not at all) to 3 (nearly every day). The scores on GAD-7 range between 0-21, with higher scores indicating higher levels of anxiety.

Resilience levels are evaluated with the 10-item Connor-Davidson Resilience Scale (CD-RISC-10). Items are scored on a scale ranging from 0 (not true at all) to 4 (true nearly all the time). Total scores range between 0 and 40 with higher scores indicating greater resilience.

Objective engagement patterns include exercise completion and non-completion (i.e., exercise started but not finished) rates, average time spent on each exercise, engagement in self-assessment module (i.e., number of questionnaires and Ecological Momentary Assessments completed), the number of objects collected in the "virtual room", the number of times the app was accessed. Log data is used to evaluate objective engagement patterns.

Exercise likeability and helpfulness is evaluated on a 5-point Likert scale ranging from 1 (not at all) to 5 (very much) every time a participant completes an exercise.

• How much did you like the exercise?
• How helpful did you find the exercise?

The likeability and helpfulness of the Self-assessment module (MapMyself) is evaluated on a scale from 1 (not at all) to 5 (very much)

• How much did you like the self-assessment (MapMyself) feature in the app?
• How helpful did you find the self-assessment (MapMyself) feature in the app?

The likeability of the Virtual Collectibles Room component is assessed on a scale ranging from 1 (not at all) to 5 (very much)

• How much do you like collecting objects in the ROOM app?

Participants are asked to evaluate the recommendation system by rating the following two questions on a scale from 1 (not at all) to 5 (very much)

• How useful do you find the in-app recommendations of the exercises?
• How well do the in-app recommendations of exercises align with your self-reported moods?

User experiences are evaluated with a User Experience Questionnaire (UEQ) measuring the Attractiveness, Perspicuity, Efficiency, Dependability, and Novelty of the app. The questionnaire includes 26 items measured on a semantic differential (e.g., attractive - unattractive). The items are scored from -3 (the most negative answer) to +3 (the most positive answer), with 0 representing a neutral answer.

The mobile intervention includes a feature (i.e., an exercise counter) where users can log in the number of times they completed an exercise outside of the app.

This counter is used to evaluate the number of exercises performed independently from the app.

Participants are asked to evaluate how often they applied ER techniques (e.g., self-compassion, breathing pattern, savouring, being mindful, reframing unhelpful thoughts) in their daily life over the past month on a scale from 0 (not at all) - 4 (daily).

• Over the past month, how frequently have you spontaneously used any of the techniques you've learned in ROOM app either to manage your emotions during challenging times or to improve your overall mood?

For evaluation of the learning transfer features in the app, participant will be asked to rate the following questions on a scale from (0 - Not at all; 100 - Very much or So far I haven't used this feature).

• How much do you like action planning with 'when-then' statements?
• How helpful do you find the action planning with 'when-then' statements?
• How much do you like to use stickers to create cues to practice the techniques?
• How helpful do you find stickers to create cues to practice the techniques?
• How much do you like the 'practice semi-guided' feature of the app?
• How helpful do you find the 'practice semi-guided' feature of the app?