# Conducting Behavioural Experiments Using an App-Based Self-Help Program for Social Anxiety Disorder (SMASH): Outcomes of a Quasi-Experimental Pre-Post Pilot Trial

## TL;DR

A new smartphone app for treating social anxiety disorder shows promising results in reducing symptoms and improving mental health.

## Contribution

A novel unguided smartphone-based self-help program for social anxiety disorder with demonstrated effectiveness in a pilot trial.

## Key findings

- Over 50% of participants experienced reliable improvement in social anxiety disorder symptoms and anxiety-related beliefs.
- The amount of completed behavioral experiments moderated treatment success in reducing symptom severity.

## Abstract

Social Anxiety Disorder (SAD) is a prevalent mental disorder characterised by fear of negative evaluation. Although effective treatment approaches are available, access remains limited due to psychological and organisational barriers. Internet-based cognitive behavioural therapy (iCBT) has shown promising results and may facilitate an easy and more resource-efficient access to treatment.

We developed an app-based self-help intervention for SAD based on the Clark and Wells treatment program, implemented as an unguided smartphone application, which was evaluated in this quasi-experimental pre-post pilot study consisting of N = 33 patients with a primary diagnosis of SAD. Feasibility was assessed through usage parameters and qualitative feedback. Effectiveness was evaluated in regard to SAD and depression, using clinician-rated measures (LSAS, QIDS-C) at post-treatment (12 weeks) and self-report measures (SPIN, SCQ, BDI-FS) at midpoint and post-treatment. Additionally, moderating effects of usage parameters on symptom reduction were examined.

Clinician- and self-reported SAD symptoms were significantly reduced at post-measurement (within-group effect sizes LSAS: η2 = .54; SPIN: η2 = .47), with 52% of patients achieving a clinically significant improvement. Despite moderate overall adherence, the amount of conducted behavioural experiments moderated reduction in self-reported SAD symptom severity and SAD-related cognitions. Open feedback supported feasibility and acceptability of the app.

In conclusion, findings provide preliminary support for feasibility, acceptability, and potential effectiveness of Mindable: Soziale Phobie. A randomised controlled trial will further evaluate the effectiveness and explore the impact of therapist guidance.

Newly developed unguided iCBT for SAD demonstrates large pre-post treatment effects on self- and clinician-reported SAD and depressive symptom severity.Over 50% of participants experienced reliable improvement in SAD symptoms and anxiety-related beliefs.High variance in adherence, with the amount of completed exposures moderating treatment success.

Newly developed unguided iCBT for SAD demonstrates large pre-post treatment effects on self- and clinician-reported SAD and depressive symptom severity.

Over 50% of participants experienced reliable improvement in SAD symptoms and anxiety-related beliefs.

High variance in adherence, with the amount of completed exposures moderating treatment success.