A self-help fully automated digital intervention to improve subthreshold depressive symptoms among older adults in a socioeconomically deprived region of Brazil (PRODIGITAL): a pragmatic, two-arm randomised controlled trial

BackgroundSubthreshold depression is a risk factor for major depression and is associated with increased morbidity and mortality, especially in poorly resourced settings. There is emerging evidence that digital interventions may be effective at improving depressive symptoms in High Income Countries but not Low-and Middle-Income settings. We aimed to evaluate the effectiveness of the Viva Vida digital intervention at improving symptoms of subthreshold depression among older adults in socioeconomically deprived settings in Brazil. MethodsPRODIGITAL was a single blind, two-arm, individually randomised controlled trial conducted in 46 primary care clinics in Guarulhos, Brazil. Individuals aged 60+ years were randomly contacted by phone for a screening assessment. Those who presented with anhedonia and/or depressed mood (Patient Health Questionnaire (PHQ)-2), and who subsequently scored between 5 and 9 on the PHQ-9 were invited to participate. The intervention (Viva Vida) arm received a self-help fully automated programme sent via WhatsApp with no support from healthcare professionals. Forty-eight audio and visual messages based on psychoeducation and behavioural activation approaches were delivered over six weeks. The control arm received a single message with information about depression. The primary outcome was the PHQ-9 at three months follow-up. All primary analyses were performed according to allocated arm with imputed data. The trial is registered with ReBEC, RBR-6c7ghfd. FindingsParticipants were recruited between 8 September 2021 and 19 August 2022. Of the 454 participants enrolled, 223 were randomised to the intervention arm and 231 to receive the single message. A total of 385 (84{middle dot}8%) completed the three-month follow-up assessment; no difference in mean PHQ-9 scores between the arms (adjusted difference: -0{middle dot}61; 95% CI: -1{middle dot}76, 0{middle dot}53; p=0{middle dot}290) was observed. InterpretationThese results demonstrate that a fully automated digital programme did not help to improve subthreshold depressive symptoms amongst older adults. More research is needed to understand how such interventions can be adapted to reduce depressive symptoms as well as prevent against major depression in low-resourced settings. FundingSao Paulo Research Foundation and Joint Global Health Trials Research in contextEvidence before this study We searched PubMed for randomised controlled trials on Oct 20, 2023, using the search terms (((((((digital) OR (internet)) OR (web)) OR (mobile)) OR (e-health) OR (technology) AND (((subthreshold) OR (subclinical)) OR (subsyndromal))) AND (((depression) OR (depressive)))) AND (((older) OR (elderly) OR (senior))). We did not apply any restrictions on languages or date of publication. Two studies assessing a fully automated digital intervention for subthreshold depression were found. An internet-based cognitive behavioural therapy (iCBT) was delivered to adults aged 50+ years in the Netherlands, whilst automated emails using self-help behaviour strategies (Mood Memos) was sent to adults from 18 to 78 years (mean age of 36 years) in Australia. The interventions showed improvement on depressive symptoms at ten (iCBT) and six weeks (Mood Memos). Like the Viva Vida, one study conducted with adults in China used a messaging application (WeChat). However, WeChat offers more features, and the iCBT programme was guided by clinical psychologists. Added value of this studyWe report a self-help fully automated digital psychosocial intervention for subthreshold depression among older adults in Brazil. To the best of our knowledge, this is the first psychosocial intervention of this kind in a low-and middle-income country. The intervention was designed to be user-friendly and accessible to a population with low literacy and limited digital skills. While a significant portion of participants engaged with the programme by opening most of the messages, we did not observe any difference in improving depressive symptoms. Implications of all the available evidenceFully automated digital interventions with no support of health or lay professionals are usually low cost and can easily be scaled up. Consequently, they have the potential to improve access to care and help reduce the mental health treatment gap in an affordable way. When tailored to socioeconomically vulnerable individuals, these interventions can also help promote more equitable access to care. Future studies should focus on understanding how to adapt such interventions to be effective for subthreshold depression.