# Examining an entirely self-guided transdiagnostic internet-delivered intervention ‘in the wild’: A randomised controlled trial for anxiety and depression with minimal inclusion criteria

## TL;DR

A self-guided online therapy program for anxiety and depression was tested in real-world conditions and showed significant improvements compared to a control group.

## Contribution

This is the first randomized controlled trial of a self-guided transdiagnostic internet intervention under real-world conditions with minimal inclusion criteria.

## Key findings

- Participants in the treatment group showed significant improvements in anxiety and depression compared to the control group.
- 25% of the treatment group met criteria for clinically meaningful change in anxiety, and 27% in depression.

## Abstract

Entirely self-guided transdiagnostic internet-delivered psychological interventions have considerable potential for increasing access to care for adults with anxiety and depression. The current study sought to examine such an intervention under real-world conditions using minimal inclusion and exclusion criteria. Three-hundred and ninety participants were randomised to either an immediate treatment group or a waitlist control group. The intervention consisted of 5 core modules delivered over 8 weeks, according to a structured timetable and with automated emails. Fifty-three percent of participants completed ≥4 of the core modules, and 75 % reported being satisfied with the intervention. At post-treatment, significant improvements were observed in the treatment group compared with control in both anxiety (treatment = 19 % [95 % CI: 12, 26]; control = 8 % [95 % CI: 2, 15]) and depression (treatment = 21 % [95 % CI: 13, 28]; control = 5 % [95 % CI: −1, 12]). These improvements were reflected in significantly greater proportions of participants meeting criteria for clinically meaningful change (≥50 % reduction) in the treatment group for both anxiety (treatment = 25 % [95 % CI: 19, 31]; control = 9 % [95 % CI: 5, 16]) and depression (treatment = 27 % [95 % CI: 20, 36]; control = 8 % [95 % CI: 5, 14]), with numbers needed to treat (NNTs) of 6.6 and 5.3, respectively. The findings of the current study support the potential of entirely self-guided transdiagnostic internet-delivered interventions, particularly for people for whom speaking with a clinician represents a barrier to care, or contexts where the resources for clinician-guided intervention are not available.

•Entirely self-guided and transdiagnostic interventions have public health potential.•No randomised controlled trials under real-world conditions have been published.•Relatively high levels of treatment engagement and satisfaction were observed.•Significant improvements in anxiety and depression were observed over control.

Entirely self-guided and transdiagnostic interventions have public health potential.

No randomised controlled trials under real-world conditions have been published.

Relatively high levels of treatment engagement and satisfaction were observed.

Significant improvements in anxiety and depression were observed over control.