JMIR Publications

ABSTRACT

Background:

Evidence-based digital health programs have shown efficacy as primary tools to improve emotional and mental health, as well as supplementary support to individuals undergoing psychotherapy for anxiety, depression, and other mental health disorders. However, less is known about the dose response to digital health interventions.

Objective:

The objective of the study was to examine the effect of time in program and program usage on symptom change among individuals enrolled in a comprehensive digital mental health program.

Methods:

Participants (N=18,626) were adults aged 18 years and older enrolled in myStrength for at least four weeks as part of their employee wellness benefit, who completed baseline, two-week, two-month, and six-month surveys querying symptoms of anxiety (GAD-7) and depression (PHQ-9). Linear growth curve models were used to analyze the effect of average weekly program usage on subsequent PHQ-9 and GAD-7 scores for participants with scores indicating severe depression (PHQ-9 ≥ 20) or anxiety (GAD-7 ≥ 15). All models adjusted for baseline score and demographics.

Results:

Participants in the study were 77.4% female and had a mean age of 45 years with an average enrollment time of 3 months. At baseline, participants reported an average of 11.0 (SD 6.6) on the PHQ-9 and 9.39 (SD 6.04) on the GAD-7. Those who reported six-month results had an average of 9.18 (SD 6.79) on the PHQ-9 and 8.18 (SD 6.15) on the GAD-7. Participants with severe scores had a significant improvement of 2.97 (SE=0.35) and 3.97 (SE=0.46) at each time point for anxiety and depression, respectively (t=-8.53 and t=-8.69, respectively; Ps<0.001). Those withs severe baseline scores also saw a reduction of 0.27 (SE=0.08) and 0.25 (SE=0.09) points in anxiety and depression, respectively, for each additional program activity per week (t=-3.47 and t=-2.66, respectively; Ps<0.05). 

Conclusions:

The study found a clinically significant reduction of approximately 9 points for anxiety and 12 points for depression after 6 months of enrollment, indicating that interventions targeting mental health must maintain engagement for as long as possible to maximize clinical impact. Moreover, a dosing effect indicating improvement in outcomes with increases in engagement every other day for both depression and anxiety, suggesting that digital health programs that provide both interesting and evidence-based activities to further improve mental health outcomes could be more successful.