Background: Research typically shows a higher preference for professionally-led face-to-face mental health interventions over digital ones. It remains unclear in which circumstances digital self-help tools are preferred. To address this gap, it is important to examine user characteristics that may help predict when digital interventions are more desirable, ultimately guiding their design to enhance engagement and appeal. Objective: To examine how distress severity and capacity to invest effort relate to intervention preferences, using an ecological assessment of individuals who seek to receive feedback on their mental health. Methods: A comprehensive digital mental health screening tool providing automated feedback was developed and advertised on social media. The sample comprised 684 adult participants aged 18-82 who opted to complete the screening to receive feedback on their mental health state. Participants completed questionnaires measuring general psychological distress, depression, generalized anxiety and demographics. Kessler Psychological Distress Scale–6 was used as the primary measure for distress. Participants were also presented with questions measuring capacity to invest effort and preferences for a professional vs digital self-help tools and for psychotherapy vs a mobile application. The effectiveness of distress, capacity to invest effort, and background characteristics in predicting preferences (a professional vs digital self-help tools; psychotherapy vs a mobile application) was examined using hierarchical linear regressions. The distributions of dichotomized preferences were plotted against distress and capacity to invest effort for transparent visualization. Results: A hierarchical linear regression found that distress, capacity to invest, and currently being in psychotherapy significantly predicted preference for a professional vs digital self-help tools. Distress (β=.25, 95% CI .18 to .32, P<.001 and capacity to invest effort ci .16 .30 p were the strongest predictors with similar effect size. model explained of variance in preference uniquely contributing most distressed participants low preferred digital self-help tools whereas high favored a professional. results obtained when using phq-4 as an alternative distress measure. remained significant .10 .26 predicting for psychotherapy vs mobile application while was not .05 conclusions: this study highlights that interventions is driven by reduced intervention. attempts reduce mental health treatment gap through should focus on optimizing elicited users improve desirability engagement.>