Evaluation of a brief unguided psychological online intervention for depression: A controlled trial including exploratory moderator analyses

BACKGROUND: Psychological online interventions (POIs) reduce depression but we know little about factors influencing their effectiveness. We evaluated a new, brief POI for depression and conducted exploratory moderator analyses. METHODS: In this online trial (German Clinical Trials Register; DRKS00011045), we allocated participants to treatment as usual (TAU; n = 67) or POI (n = 65). At first, we randomized participants; later we allocated participants based on depression severity in order to counter baseline differences. The unguided POI addressed behavioral activation and depressive thinking in a single module with 25 webpages (including a smartphone application). We did one assessment at baseline and a post-assessment four weeks later. RESULTS: At post-assessment, depression (p = .586), behavioral activation (p = .332), and dysfunctional attitudes (p = .499) did not differ between groups. When concurrent treatments (medication/psychotherapy) remained constant/decreased, the POI outperformed TAU (p = .031). POI-participants with lower willingness to change (p = .030) or higher education (p = .017) were less likely to worsen (i.e., experience increased depressive symptoms) compared to TAU. DISCUSSION: The targeted sample size was not reached, measurements were self-reported, and randomization failed. The POI's content may have been too limited. Concurrent treatments, which were more often sought out by TAU participants, diminished group differences and should be considered in future studies. Brief POIs may protect against worsening of depressive symptoms among highly educated participants or those with low willingness to change.