Digital Health Applications for Mental Disorders in Germany Among Users and Nonusers on Actual and Intended Use, Self-Reported Completion, and Reasons for Discontinuation: Cross-Sectional Survey.

backgroundDigital health interventions, including mobile health apps, increasingly complement outpatient mental health care. In Germany, certified digital health applications (DiGA [Digitale Gesundheitsanwendungen]) can be prescribed and reimbursed in the statutory health care system. However, real-world evidence on patient-reported use of DiGA for mental disorders remains limited.

objectiveThis study aimed to analyze usage patterns and experiences among DiGA users and expectations among nonusers. Among users, we examined duration of active use, self-reported completion, and experienced reasons for discontinuation; among nonusers, whether DiGA use would be an option and the perceived relevance of hypothetical reasons for discontinuation.

methodsWe conducted an anonymous cross-sectional mixed-mode survey among adults insured by Techniker Krankenkasse, Germany's largest statutory insurer. Random samples of 2000 individuals per group were invited in April 2024, and data collection ended in September 2024. Users received an activation code for a DiGA authorized for mental disorders. Nonusers had a documented diagnosis for which a DiGA was available but had no prior use. Analyses were descriptive, using available cases, frequencies, and medians with IQRs for ordinal Likert-type items. Actual and intended use were treated as distinct. Exploratory subgroup analyses were conducted.

resultsOverall, 1413 participants were included in the analysis (769 of 2000 invited users; 644 of 2000 invited nonusers), with response rates of 38.5% (95% CI 36.3%-40.6%) and 32.2% (95% CI 30.2%-34.3%), respectively. A total of 840 of 1249 (67.3%; 95% CI 64.6%-69.8%) participants were female. Nonusers were older and more often lived in rural areas. Among users, 487 of 687 (70.9%; 95% CI 67.4%-74.2%) reported active use for at least 5 weeks; 409 of 700 (58.4%; 95% CI 54.7%-62.0%) reported completion of their DiGA program. The proportion of reported completions increased from 111 of 250 (44.4%; 95% CI 38.4%-50.6%) among those aged 18-40 years to 85 of 112 (75.9%; 95% CI 67.2%-82.9%) among those aged 61 years and older. The most frequently endorsed reasons for discontinuation among users reporting noncompletion were lack of motivation (151/272, 55.5%; 95% CI 49.6%-61.3%) and insufficient personalization (114/255, 44.7%; 95% CI 38.7%-50.8%). Among nonusers, the most frequently endorsed hypothetical reasons for discontinuation were mismatch with their condition (431/540, 79.8%; 95% CI 76.2%-83.0%) and technical difficulties (432/545, 79.3%; 95% CI 75.7%-82.5%).

conclusionsThis study provides patient-reported real-world evidence on certified and reimbursable digital mental health interventions. Many users reported weeks of active use, but noncompletion remained common and was more frequent among younger users. Lack of motivation as a frequently reported reason for discontinuation suggests that supporting continued engagement may be important during DiGA use. Beyond Germany, these findings may support implementation of digital mental health interventions in other health care systems. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/56205.