Determinants and outcome correlates of engagement with a mobile mental health intervention for depression and anxiety in middle-aged and older adults

Objectives: To examine baseline factors (i.e., age, gender, mobile device proficiency, sensory impairment) associated with app engagement in a 12-week mental health app intervention and to explore whether app engagement predicts changes in depression and anxiety symptoms among middle-aged and older adults.Method: Mobile device proficiency, sensory impairment, depression, and anxiety symptoms were measured using questionnaires. App engagement was defined by metrics characterizing the core intervention features (i.e., messages sent to therapist, mindfulness meditation minutes, action tasks completed). Multiple regressions and multilevel models were conducted.Results: Forty-nine participants (M age = 57.40, SD = 11.09 years) enrolled. Women (beta = .35, p < .05) and participants with less sensory impairment completed more action tasks (beta = -.40, p < .05). Depressive and anxiety symptoms measured within the app declined significantly across treatment. Clinical significant improvements were observed for depression in 48.9% and for anxiety in 40% of participants. App engagement metrics were not predictive of depression or anxiety symptoms, either incrementally in time-lagged models or cumulatively in hierarchical linear regression analyses.Conclusion: App engagement is multifaceted; participants engaged differently by gender and ability. Participation in this digital mental health intervention reduced depression and anxiety symptoms, but these findings should be interpreted with caution as the study did not include a control condition. Our findings underscore the importance of considering individual factors that may influence use of a digital mental health intervention.