JMIR Publications

ABSTRACT

Objective:

This pilot study evaluated the feasibility, acceptability, and preliminary effectiveness of Deprexis, a fully self-guided internet-based intervention for depression, in U.S. military Veterans with mild to moderate depressive symptoms.

Methods:

This open-label pilot trial recruited 19 Veterans with mild to moderate depression (QIDS-SR scores 6-20) for an 8-week course of Deprexis, with assessments at baseline, post-treatment (8 weeks), and follow-up (16 weeks). Primary outcomes included depressive symptoms (QIDS-SR), functional disability (WHODAS-2.0), and symptom-related disability (SDS). Feasibility was assessed through recruitment and retention rates, while acceptability was measured using the Credibility/Expectancy Questionnaire and Client Satisfaction Questionnaire. Multilevel models examined change over time, with effect sizes calculated using pooled standard deviations from unconditional models.

Results:

Recruitment and retention targets were met, with 79% of participants meeting adherence criteria (i.e., >= 60 minutes of active program use). The program was perceived as credible and received positive acceptability rating, with no safety concerns reported. Depression scores showed significant improvement from baseline to post-treatment (d=-0.47-d=-0.53) and follow-up (d=-0.70 - d=-0.77) with moderate-to-large effect sizes in both the total sample and completers. Functioning improvements were observed among completers at follow-up (d = -0.41).

Conclusions:

This pilot trial demonstrates that Deprexis is feasible and acceptable for Veterans with mild to moderate depression, with preliminary evidence of effectiveness for depressive symptoms. The delayed emergence of functional improvements and sustained gains at follow-up support the potential of this scalable intervention. Results provide a strong foundation for the planned randomized controlled trial.