Randomized controlled trial of a Cognitive-Behavioural Therapy Mobile Application (INTELLECT) in alleviating anxiety and depressive symptoms among Japanese employees with depressive symptoms (Preprint)
Authors: Yokomitsu Kengo , Oimatsu Riki , Toh Sean Han Yang , Sündermann Oliver 
Published: June 2024

BACKGROUND

In Japan, the prevalence of anxiety and depressive symptoms within the working population have risen. This has been accentuated by the economic repercussions of the COVID-19 pandemic and the social isolation resulting from remote work setups. Mobile health (mHealth) applications, particularly those incorporating Cognitive Behavioral Therapy (CBT) features, have shown potential in addressing these symptoms. These self-guided CBT interventions hold promise in alleviating the heightened depressive and anxiety symptoms often observed among Japanese employees.

OBJECTIVE

Using a randomized controlled trial (RCT), we compared the efficacy of the “INTELLECT” app against a no-treatment control group in improving depressive symptoms and CBT skills among Japanese full-time employees at post-intervention and at 2-month follow-up.

METHODS

A total of 123 full-time Japanese employees were randomly allocated to either the intervention group (INTELLECT), where they engaged with self-help CBT features, or to a control group receiving no treatment. Intervention participants were required to engage with these features for at least 20 minutes per week over a span of 4 weeks.. Weekly self-reported assessments were collected from all participants starting from baseline and continuing until the end of the 4-week intervention period. Subsequent assessments were conducted at 1-month and 2-month follow-up intervals. Linear mixed models (LMMs) were used to evaluate any effects of the self-guided intervention on depressive symptoms, as measured by the Patient Health Questionnaire-4 (PHQ-4), and cognitive behavioral skills, as measured by the Cognitive Behavioral Therapy Skills Scale (CBTSS). Feasibility, usability, and acceptability ratings of the app were also examined using the Implementation Outcome Scales for Digital Mental Health (iOSDMH).

RESULTS

The final sample (n=73) consisted of 46 (63.0%) female participants, 23 (31.5%) male participants, and 4 (5.5%) participants identifying as other genders, with a mean age of 40.4 (SD=10.7) years. Significant time x group interactions were found at post-intervention and 2-month follow-up, with the intervention group (n=34) reporting significantly lower depressive symptoms than the control group (n=38) at post-intervention (Cohen’s d=-0.57 [-1.07, -0.06]) and 2-month follow-up (Cohen’s d=-0.85 [-1.38, -0.32]). In addition, intervention participants reported significantly greater improvements in self-monitoring cognitive skills than control participants at post-intervention (Cohen’s d=0.68 [0.17, 1.18]) but not follow-up (Cohen’s d=0.50 [-0.05, 1.02]).

CONCLUSIONS

This study provides evidence that CBT features on the INTELLECT app are effective in improving depressive symptoms and self-monitoring cognitive skills.

CLINICALTRIAL

This RCT was registered with the University hospital Medical Information Network (UMIN) Center (Registration number: UMIN000051354).