Participant is randomized to receive a 30-minute information session

email support throughout the 4 week intervention period

Text message microsupport throughout the 4 week intervention period

The NIH Toolbox Loneliness is a 5-item questionnaire where participants report how often in the past week they have felt loneliness. It is scored on a 5-point Likert scale where 1 = never to 5 = always. The total possible range of scores is 5-25 where higher scores indicate a greater sense of loneliness.

Item 9 on the Beck Depression Inventory (BDI) assesses suicidal thoughts or wishes. The possible scores for this item are 0, 1, 2, or 3, corresponding to different levels of severity. A score of 0 indicates no suicidal thoughts, while higher scores indicate increasing severity of suicidal ideation.

The Five Facet Mindfulness Questionnaire Acting with Awareness Subscale is an 8-item subscale where participants report on their general ability to focus. It is scored on a 5-point Likert scale where 1 = never or very rarely true to 5 = very often or always true. The total possible range of scores is 8-40 where higher scores indicate a greater ability to focus.

The Decentering subscale of the Experience Questionnaire is an 11-item questionnaire where participants report on their ability to decenter from their experience. It is scored on a 5-point Likert scale where 1 = never to 5 = all the time. The total possible range of scores is 11-55 where higher scores indicate a greater ability to decenter from experience.

The HM Index is a 17-item questionnaire assessing qualities trained in the HMP app (awareness, connection, insight, purpose). It is scored on a 0- to 4-point Likert scale where 0 = a low amount (e.g., never, not at all, none of the time) and 4 = a higher amount (e.g., always, to the highest degree, all of the time) of a particular quality. Total scores for the Awareness subscale is 0 to 16 where higher scores indicate more awareness.

The HM Index is a 17-item questionnaire assessing qualities trained in the HMP app (awareness, connection, insight, purpose). It is scored on a 0- to 4-point Likert scale where 0 = a low amount (e.g., never, not at all, none of the time) and 4 = a higher amount (e.g., always, to the highest degree, all of the time) of a particular quality. Total scores for the Connection subscale range from 0 to 24, where higher scores indicate more connection.

The HM Index is a 17-item questionnaire assessing qualities trained in the HMP app (awareness, connection, insight, purpose). It is scored on a 0- to 4-point Likert scale where 0 = a low amount (e.g., never, not at all, none of the time) and 4 = a higher amount (e.g., always, to the highest degree, all of the time) of a particular quality. Total scores for the Insight subscale range from 0 to 12, where higher scores indicate more insight.

The HM Index is a 17-item questionnaire assessing qualities trained in the HMP app (awareness, connection, insight, purpose). It is scored on a 0- to 4-point Likert scale where 0 = a low amount (e.g., never, not at all, none of the time) and 4 = a higher amount (e.g., always, to the highest degree, all of the time) of a particular quality. Total scores for the Purpose subscale range from 0 to 16, where higher scores indicate more purpose.

The Wellbeing Growth Mindset scale is a 3-item scale where participants report whether they believe wellbeing is malleable (e.g., "Your well-being is something about you that you can't change very much."). It is scored on a 6-point Likert scale where 1 is "strongly disagree" to 6 being "strongly agree." Total scores range from 3 to 18 where higher scores indicate greater wellbeing growth mindset.

DWAI is a six-item questionnaire designed to assess the working alliance within the Healthy Minds Program (HMP) app. It measures the user's connection and agreement with the app, focusing on the bond, tasks, and goals of the therapeutic relationship. It is scored on a 7-point Likert scale, with scores ranging from 6-42. Higher scores indicate a stronger working alliance with the HMP app.

Morning daily diary will include single-item measures of mindfulness, decentering, connection, purpose, depression, anxiety, happiness, energy, stress, busyness, rumination (2 items), sleep quality, motivation to practice meditation, and expectations and challenges related to using the HMP. Each item will be rated on a 5-point Likert scale (1 = not at all, 5 = very much). Higher scores indicate greater levels of the respective construct, such as higher mindfulness, greater decentering, stronger sense of purpose, greater happiness, more severe depression or anxiety, better sleep quality, or greater motivation and perceived helpfulness or frustration with HMP use that morning. Daily means with and standard deviations will be reported.

Evening daily diary will include single-item measures of mindfulness, decentering, connection, purpose, depression, anxiety, happiness, energy, happy event, stress exposure, rumination (2 items), and expectations related to using the HMP. Each item will be rated on a 5-point Likert scale (1 = not at all, 5 = very much). Higher scores indicate greater levels of the respective construct, such as higher mindfulness, greater decentering, stronger sense of purpose, more severe depression or anxiety, happy event and stressor exposure experience, or greater motivation and perceived helpfulness with HMP use that day. Daily means with and standard deviations will be reported.

Participants' engagement in formal mindfulness practice will be assessed twice a day with a binary yes/no response. Formal practice is defined as using the HMP app.

Participants' engagement in informal mindfulness practice will be assessed twice a day with a 5-point Likert scale (1 = not at all, 5 = all day long). Informal practice is defined as applying well-being practices in daily life.

Participants will indicate whether they received a text message from the study that day (yes/no). If they respond "yes," they will then report whether the message encouraged them to apply a wellbeing strategy (yes/no) and rate the extent to which they applied the strategy in their day-to-day activities on a 5-point Likert scale (1 = not at all, 5 = very much).

Participants who received a text message and applied a well-being strategy will be asked to rate the extent to which they applied the strategy in their day-to-day activities on a 5-point Likert scale (1 = not at all, 5 = very much).

The PROMIS Anxiety Score is a computer adaptive measure of feelings of anxiety in the past 7 days. This is a computer-adaptive survey scored on a 5-point Likert scale from 1 (never) to 5 (always) with higher scores indicating increased anxiety. It provides t-scores with a mean of 50 and SD of 10. Higher t-scores indicate higher levels of anxiety.

The 3-item Medication and Therapy Questionnaire collects information on whether participants received medication or therapy for mental health concerns in the past month. Each item is a yes/no question.

WHODAS 2.0 is a 12-item measure which evaluates healthy-related disability in the past 30 days across 6 domains (cognition, mobility, self-care, getting along, life activities, and participation). It is scored on a 5-point Likert scale were 0 = None and 4 = Extreme or cannot do. The total score ranges from 0 to 48 with higher scores indicating higher level of impairment.

PANAS is a 10-item measure assessing positive (5 items) and negative (5 items) emotions using a 5-point Likert scale, in which 1 = Never and 5 = Always. The total score of each scale ranges from 5-25. Positive Affect score means higher levels of enthusiastic, alert, and pleasurable engagement. A higher Negative Affect score indicates higher level of distress, nervousness, or anger.

AUDIT-C is a 3-item brief alcohol screen using a 5-point Likert scale. The possible range of score is 0-12. Higher scores suggest more hazardous alcohol use or active alcohol use disorders.

HMP engagement is a 16-item measure which assess participant's usage experience with the Healthy Minds Program. It is scored on a 5-point Likert scale where 1 = Strongly disagree to 5 = Strongly agree. The total possible range of scores is 0-80 where higher scores indicate more positive engagement with the app.

The adapted CSRI includes five items assessing the number of primary care visits, mental health outpatient visits, emergency or urgent care visits, hospital nights, and mental health or sleep medications used during a 12-week recall period. Responses are recorded as numeric counts ranging from zero to no fixed upper limit, with higher values indicating greater healthcare service use and higher associated healthcare costs.

The WPAI is a 6-item questionnaire assessing health-related absenteeism, presenteeism, and activity impairment. Scores are calculated as percentages with higher values indicating greater impairment and lower productivity.

The Flourishing Index is a 10-item questionnaire where participants report their general level of flourishing (e.g., well-being, health, etc.). It is scored on a 0 to 10-point scale, with anchors varying across items. The total score ranges from 0 to 100 with higher scores indicating higher flourishing.

The PROMIS Sleep Disturbance Score is a measure of sleep in the past 7 days. This is a computer-adaptive survey scored on a 5-point Likert scale with higher scores indicating increased sleep disturbance. It provides t-scores with a mean of 50 and SD of 10. Higher t scores indicate higher levels of sleep disturbances.

The SAI is an 8-item self-report tool to evaluate how users perceive the support and accountability provided by coaches in digital mental health interventions. It uses a 7-point Likert scale (1 = Strongly Disagree; 7 = Strongly Agree). Scores range from 8 to 56. Higher scores indicate a stronger sense of supportive accountability from their coach perceived.

The RRS-Brooding subscale is a 5-item, 4-point measure of rumination. Each item indicates the frequency of each event by rating a four-point Likert scale ranging from 1 (Almost never) to 4 (Almost always). The total score ranges from 5-20, with higher scores indicating increased tendency to ruminate.

This measure assesses how much the participant believes that the training program was helpful to them. This has two aspects to it: (1) what the participant thought would happen and (2) what the participant feels will happen. Each scale is scored from 1-9 with higher scores indicating better treatment expectancy.