Impact and mechanism of problem-solving therapy on self-efficacy in elderly depression with type 2 diabetes (PRIORITY): Study protocol for a feasibility randomised controlled trial
Authors: Dong Xie , Menglin Zhang , Yongjiao Kang , Naiyan Wen , Min Zhao , Xue Wu , Yuyuan Huang , Haochen Dai 
Published: January 2025

Background
Problem-Solving Therapy (PST) has demonstrated potential in improving emotional regulation and self-efficacy by helping patients develop practical solutions to daily challenges. This approach shows promise in the management of mood disorders. Type 2 diabetes is a chronic condition characterized by elevated blood glucose levels, often coexisting with mental health disorders such as anxiety and depression. These psychological comorbidities can interfere with blood glucose control, leading to poorer health outcomes. However, the effects of PST on elderly patients with type 2 diabetes and depression, particularly in relation to gut microbiota, remain underexplored. Emerging research suggests that gut microbiota may influence the connection between emotional states and overall health. Investigating how PST affects psychological health and gut microbiota in this population could provide valuable insights for more comprehensive treatment strategies.
Key Aims
The primary aim of this study is to conduct a randomized controlled trial (RCT) to evaluate the effects of Problem-Solving Therapy (PST) in elderly patients with type 2 diabetes. The study will explore the mechanisms involved, particularly focusing on the gut-brain axis as a potential mediator in the therapeutic process.
Research Plan
This study will employ a feasibility randomized controlled trial (RCT) design to a[1]ssess the effects of PST on both psychological and physiological outcomes. The trial will focus on elderly patients with type 2 diabetes and depression, as this population is particularly vulnerable to the compounded effects of these conditions. We will compare two groups:
The study will recruit 96 elderly patients (aged 60–80 years) with type 2 diabetes and depressive symptoms from a tertiary hospital in China. Participants will be randomly assigned to either the intervention group (PST + standard treatment) or the control group (standard treatment only). This trial will be a single-blind, pragmatic, two-arm RCT, which will evaluate the impact of 8 weeks of PST on psychological and physiological outcomes. Pre- and post-intervention stool samples will be collected for 16S rDNA gene sequencing to analyze changes in gut microbiota composition and identify potential mechanistic changes.
Methods
A total of 96 elderly patients with type 2 diabetes and depression will be recruited, ensuring they meet specific inclusion and exclusion criteria. Participants will be randomly assigned to either the control group (standard treatment) or the intervention group (PST + standard treatment). Randomization will be performed using a random number table, with 48 patients in each group.
The PST intervention will be delivered in structured sessions over 8 weeks, aimed at enhancing participants' coping skills, problem-solving abilities, and emotional regulation. Clinical outcomes will be assessed using the Self-Rating Depression Scale (SDS) and the General Self-Efficacy Scale (GSES). Additionally, stool samples will be collected at baseline and post-intervention for 16S rDNA gene sequencing to evaluate changes in the gut microbiota.
After the 8-week intervention, between-group differences will be analyzed with respect to:
1.Depressive symptoms (SDS scores)
2.Self-efficacy (GSES scores)
3.Gut microbiota composition
Data analysis will involve appropriate statistical methods to compare the two groups.
Discussion
This study aims to assess whether Problem-Solving Therapy can effectively improve depressive symptoms and self-efficacy in elderly patients with type 2 diabetes. The findings will provide valuable evidence for the clinical application of PST and lay the groundwork for refining intervention strategies in future research.
Trial Registration: This protocol has been registered at ClinicalTrials.gov.