3 - (OP14) Effectiveness of a CBT-based Mobile Intervention in a Developing Country: A Randomized Controlled Trial from Türkiye

This study examines the effectiveness of a six-week, cognitive behavioral therapy (CBT)- based mobile application designed to reduce symptoms of depression, anxiety, and stress, using a randomized controlled trial (RCT) design. The intervention consists of structured CBT modules organized into three symptom-focused tracks (depression, anxiety, and stress). Participants in the experimental group were assigned to a primary content track based on standardized z-scores reflecting baseline symptom severity.
A total of 201 participants were recruited through social media announcements, paid advertisements, and randomly allocated to either an experimental group (n = 121) or a waitlist control group (n = 80). Within the experimental group, participants were further classified into two subgroups: individuals using the mobile application as a standalone intervention and those using the application while ongoing psychotherapy and/or psychiatric medication. This distinction will be examined analytically to evaluate potential differential effects of concurrent psychological support. Participants in the experimental group were also distributed across symptom-specific tracks targeting depression (n = 39), anxiety (n = 36), or stress (n = 46). Control group participants received no intervention during the study period.
The study began on January 12 and will conclude on February 22. Assessments were administered at baseline (pre-intervention), post-intervention (week 6; January 22), and at week 10 weeks after the study (week 10; March 22). Outcome measures included the Depression Anxiety Stress Scale–21 (DASS-21), Generalized Anxiety Disorder–7 (GAD-7), Patient Health Questionnaire–9 (PHQ-9), and Perceived Stress Scale–10 (PSS-10).
Daily mood monitoring was conducted twice daily via in-app reminders, and CBT-based journaling forms were used to support engagement and adherence. To enhance sustained participation, the application incorporated a gamification-based reinforcement system grounded in behavioral learning theory, whereby users earned progressively hierarchical badges (Bronze through Master levels) contingent on weekly module completion. Psychoeducational content was delivered through animated doodle videos to reduce cognitive load, and guided audio recordings supported experiential exercises such as breathing and relaxation practices.
Conducted in Türkiye, a developing country, this study contributes to the inclusion of underrepresented populations in the digital mental health literature. Although mental health applications are available in Türkiye, this research represents the first effectiveness evaluation of a CBT-based mobile application originally developed for the Turkish context and the second mobile mental health intervention study implemented in Turkish that evaluated an adaptation of an app developed elsewhere. Most digital CBT trials have been conducted in high-income countries; findings from this study address an important gap and provide evidence relevant to settings where access to traditional psychological services remains limited.