Improving Mild to Moderate Depression With an App-Based Self-Guided Intervention: Protocol for a Randomized Controlled Trial

Background Depression is one of the most prevalent mental disorders and frequently co-occurs with other mental disorders. Despite the high direct and indirect costs to both individuals and society, more than 80% of those diagnosed with depression remain with their primary care physician and do not receive specialized treatment. Self-guided digital interventions have been shown to improve depression and, due to their scalability, have a large potential public health impact. Current digital interventions often focus on specific disorders, while recent research suggests that transdiagnostic approaches are more suitable. Objective This paper presents the protocol for a study that aims to assess the efficacy of a self-guided transdiagnostic app-based self-management intervention in patients with mild or moderate depression with and without comorbid mental disorders. Specifically, we are investigating the impact of the intervention on symptoms of depression, quality of life, anxiety symptoms, and mental health–related patient empowerment and self-management skills. Methods The intervention under investigation, MindDoc with Prescription, is a self-guided digital intervention aimed at supporting individuals with mild to moderate mental disorders from the internalizing spectrum, including depression. The app can be used as a low-threshold psychosocial intervention. Up to 570 adult patients will be randomized to either receive the intervention in addition to care as usual or only care as usual. We are including adults with a permanent residency in Germany and mild or moderate depression according to International Classification of Diseases, 10th Revision, criteria (F32.0, F32.1, F33.0, and F33.1). Clinical interviews will be conducted to confirm the diagnosis. Data will be collected at baseline as well as 8 weeks and 6 months after randomization. The primary outcome will be depression symptom severity after 8 weeks. Secondary outcomes will be quality of life, anxiety symptom severity, and patient empowerment and self-management behaviors. Data will be analyzed using multiple imputations, using the intention-to-treat principle, while sensitivity analyses will be based on additional imputation strategies and a per-protocol analysis. Results Recruitment for the trial started on February 7, 2023, and the first participant was randomized on February 14, 2023. As of September 5, 2023, 275 participants have been included in the trial and 176 have provided the primary outcome. The rate of missing values in the primary outcome is approximately 20%. Conclusions Data from this efficacy trial will be used to establish whether access to the intervention is associated with an improvement in depression symptoms in individuals diagnosed with mild or moderate depression. The study will contribute to expanding the evidence base on transdiagnostic digital interventions. Trial Registration German Registry of Clinical Trials DRKS00030852; https://drks.de/search/de/trial/DRKS00030852 International Registered Report Identifier (IRRID) DERR1-10.2196/46651

• The application enables users to self-manage symptoms and related problems by providing evidence-based transdiagnostic courses and exercises to help identify, understand, and manage symptoms through self-initiated behavior change.
• The application provides users with regular guidance on whether further medical or psychotherapeutic evaluation is indicated through a general feedback on emotional health.
"MindDoc with Prescription" explicitly does not replace a medical or psychotherapeutic assessment or treatment, but can prepare and support the path to psychiatric or psychotherapeutic treatment.

Mode of Operation
The application provides an assessment tool which allows users to monitor signs and symptoms of common mental health problems and related problem areas in real-time over long time periods.Questions are asked within three blocks a day (morning, noon, evening), with each block consisting of three or more questions.In contrast to a static mood-diary or the repeated completion of static questionnaires, the underlying algorithm adjusts the number and area of questions to the answers of the user as well as to the completion rate of previous questions blocks.In addition, every question block is finished by a general mood-tracking (very bad, bad, moderate, good, very good) as well as the opportunity to track emotions and situations via text entry, pre-defined or customized tags (positive, negative, neutral).
This information is then processed to continuously provide individualized automated feedback (insights) to the user that reflect symptoms as well as potential triggers and problem areas and suggest suitable disorder-specific and trans-diagnostic self-management courses and exercises to address symptoms and problems.
As soon as the user has answered the required minimum of questions, the application provides an individualized medical orientation regarding the need for assessment of their mental-mental condition which can be shared with a specialist.
The application has four interconnected core components.
1. Continuous monitoring of symptoms of common mental disorders, related problems, and personal resources (Journal).
2. Automated feedback on general symptom load and level of functioning (Results) 3. Automated feedback on symptoms, symptom clusters and relevant problem areas, along with recommendations for exercises and courses (Insights) 4. Structured self-management courses and exercises that address problems that commonly contribute to mental health disorders (Self-Management)

Core components
Journal Users answer up to three blocks of questions per day on symptoms of common mental disorders, related problems and personal resources that can be helpful to address those symptoms and problems.Questions are chosen from a large question pool based on an adaptive algorithm that takes into account previous answers of the user.Thus, the more questions are answered, the more individualized and relevant the questions become.
Questions typically require a dichotomous answer.If a symptom is confirmed, a follow-up question is asked to assess symptom severity ("How much does this bother you?), which is rated on a four-point scale ranging from 1 to 4 with a visual anchor.
At the end of each question block, users can rate their current mood on a simple 5-point scale (very bad, bad, neutral, good, very good).Users can also add personal notes as well as predefined and customized tags to their entries.
The mood rating and the notes can be used independently of the question blocks, so users can make multiple entries per day.
A customizable alert function can be set to remind users to answer the question block at respective times via push notifications for higher response rates.

Results
If users have answered a minimum number of questions within a period of 14 days, they will get feedback on their answers regarding their symptom load.Users with a high symptom load, a high level of functional impairment or critical symptoms like suicidal tendencies are recommended to seek further assessment.
In addition to that recommendation, users are provided with summaries of their answers over predefined periods of time as well as weekly, monthly and yearly statistics.Some summaries can be exported in PDF format and can be shared with treatment providers.
Users who report suicidal tendencies are instantly and automatically directed to an automated dialogue (crisis-bot) that culminates in a direct connection to a local crisis hotline if the user agrees.In Germany, this is the Telefonseelsorge, in other countries it is a comparable service.Alternatively, the user is guided to contact a friend or family member via text message to seek help.

Insights
If users report specific symptoms or problems, or combinations of symptoms and problems repeatedly, they will receive automated feedback via insights.
Insights provide general information about symptoms, about behavior-health-links or about consequences of behaviors.They also provide an overview of possible strategies to address problems and prompt further engagement with related self-management exercises.

Self-management
The application provides a library of courses and exercises that are designed to enable the user to self-manage mental health problems.Courses can be accessed at the discretion of the user, and subscribed (i.e., full access) users have full access to the entire course library.
Courses consist of multiple exercises.For some courses it is advisable to complete the exercises in the set order, or to allow for time to implement behaviour changes between two exercises.If this is the case, this is explained to the user within the exercise.
The version of the application that has been evaluated contained the content described in the table below.