Efficacy of a Transdiagnostic Self-Help Internet Intervention for Reducing Depression, Anxiety, and Suicidal Ideation in Adults: Randomized Controlled Trial

Background Low-intensity self-guided mental health interventions that are delivered on the web may meet needs and preferences of adults with mild to moderate symptoms. However, few clinical trials have examined effectiveness transdiagnostic within a naturalistic setting. Objective This randomized controlled trial (RCT) tests video-based intervention FitMindKit in reducing depression symptoms (primary outcome), anxiety symptoms, disability, suicidal ideation, relative an attention-matched control condition called HealthWatch. Methods The RCT was conducted living Australian Capital Territory, Australia. Participants (n=1986) were recruited through using social media advertisements, screened for psychological distress, then receive one two 4-week programs: (12-module psychotherapy intervention) or HealthWatch program providing general information). assessed at baseline 4 weeks postbaseline. To maintain ecological validity trial, participants completed brief assessments without direct researcher contact incentives. Results Mixed model repeated-measures analyses variance demonstrated significantly improved (F1,701.7=3.97; P=.047), along panic (F1,706.5=5.59; P=.02) (F1,680.0=12.37; P<.001), attention condition. There no significant effects other outcomes. Conclusions Self-guided can be beneficial when directly end users internet. Despite low adherence small effect sizes, availability such is likely fill critical gap accessibility services community. Trial Registration New Zealand Clinical Trials Registry ACTRN12618001688279; http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=376113. International Registered Report Identifier (IRRID) RR2-10.1016/j.conctc.2019.100341