The Use and Effectiveness of Mobile Apps for Depression: Results From a Fully Remote Clinical Trial

Abstract

Background: Mobile apps for mental health have the potential to overcome access barriers to mental health care, but there is little information on whether patients use the interventions as intended and the impact they have on mental health outcomes.

Objective: The objective of our study was to document and compare use patterns and clinical outcomes across the United States between 3 different self-guided mobile apps for depression.

Methods: Participants were recruited through Web-based advertisements and social media and were randomly assigned to 1 of 3 mood apps. Treatment and assessment were conducted remotely on each participant's smartphone or tablet with minimal contact with study staff. We enrolled 626 English-speaking adults (≥18 years old) with mild to moderate depression as determined by a 9-item Patient Health Questionnaire (PHQ-9) score ≥5, or if their score on item 10 was ≥2. The apps were (1) Project: EVO, a cognitive training app theorized to mitigate depressive symptoms by improving cognitive control, (2) iPST, an app based on an evidence-based psychotherapy for depression, and (3) Health Tips, a treatment control. Outcomes were scores on the PHQ-9 and the Sheehan Disability Scale. Adherence to treatment was measured as number of times participants opened and used the apps as instructed.

Results: We randomly assigned 211 participants to iPST, 209 to Project: EVO, and 206 to Health Tips. Among the participants, 77.0% (482/626) had a PHQ-9 score >10 (moderately depressed). Among the participants using the 2 active apps, 57.9% (243/420) did not download their assigned intervention app but did not differ demographically from those who did. Differential treatment effects were present in participants with baseline PHQ-9 score >10, with the cognitive training and problem-solving apps resulting in greater effects on mood than the information control app (χ22=6.46, P=.04).

Conclusions: Mobile apps for depression appear to have their greatest impact on people with more moderate levels of depression. In particular, an app that is designed to engage cognitive correlates of depression had the strongest effect on depressed mood in this sample. This study suggests that mobile apps reach many people and are useful for more moderate levels of depression.

Clinicaltrial: Clinicaltrials.gov NCT00540865; https://www.clinicaltrials.gov/ct2/show/NCT00540865 (Archived by WebCite at http://www.webcitation.org/6mj8IPqQr).

Keywords: RCT; cognitive training; depression; iPST; mobile apps; problem-solving therapy; randomized controlled trial.

Figure 1

Consolidated Standards of Reporting Trials (CONSORT) diagram. EVO: Project: EVO; HT: Health Tips; PHQ-9: 9-item Patient Health Questionnaire; wk: week.

Figure 2

Participant intervention use and changes in primary outcome measures over time. (a) Average number of active intervention uses across the first 4 weeks of the study. (b) Number of participants using each active intervention by the level of adherence. (c) 9-item Patient Health Questionnaire (PHQ-9) depression scores over time for each intervention. (d) Sheehan Disability Scale scores over time for each intervention. Control: Health Tips; EVO: Project: EVO; iPST: problem-solving therapy app. Error bars indicate +/- 1 SE.

Figure 3

Changes in 9-item Patient Health Questionnaire (PHQ-9) and Sheehan Disability Scale scores moderated by baseline depression and by symptom severity for each intervention. (a) Individuals with lower baseline depression by group. (b) Individuals with higher baseline depression by group. (c) Individuals with lower baseline anxiety by group. (d) Individuals with higher baseline anxiety by group. Control: Health Tips; EVO: Project: EVO; iPST: problem-solving therapy app. Error bars represent +/- 1 SE.