Digital cognitive behavioural therapy for depression and obesity after laparoscopic sleeve gastrectomy: a study protocol

Young and middle-aged patients who simultaneously present with depression and obesity and who have undergone laparoscopic sleeve gastrectomy still face significant difficulties accessing mental health services. Cognitive behavioural therapy (CBT) has been shown to be effective for young and middle-aged patients. However, given the reliance on professional therapists, long waiting times, high costs and inconvenience of traditional CBT for busy or remote populations, a digital form of CBT would be ideal for managing these patients. Digital cognitive behavioural therapy (DCBT) has the potential to address the limitations of traditional mental health services for young and middle-aged patients with comorbid depression and obesity who have undergone laparoscopic sleeve gastrectomy. This protocol describes a randomized controlled trial designed to evaluate the effectiveness of a DCBT intervention in young and middle-aged patients with comorbid depression and obesity who have undergone laparoscopic sleeve gastrectomy. An evidence-based approach will be used in this study to develop a DCBT intervention program for the abovementioned patients. The intervention program will be further revised through expert meetings for consultation and discussion. Second, a module structure for digital cognitive behavioural therapy will be constructed, and the performance of each module will be assessed. Finally, we will cooperate with the software company to design and develop the DCBT software. During the experiment, we plan to enrol 68 patients who have undergone laparoscopic sleeve gastrectomy at a hospital in Hangzhou, Zhejiang Province. The study subjects will be evenly and randomly divided into control and experimental groups. Patients in the control group will receive the usual care following laparoscopic sleeve gastrectomy for comorbid depression and obesity. The intervention group will receive DCBT in addition to the usual care. The primary outcome of this study is the depression status of patients before and after the intervention. The secondary outcomes are patients’ physical activity levels, diet, and quality of life, which will be assessed before and three months after surgery using the International Physical Activity Scale, the Dutch Diet Behaviour Scale, and the Quality of Life Scale, respectively. The results of this ongoing randomized controlled trial will help determine whether DCBT can be recommended for hospital use and whether it can improve the outcomes of young and middle-aged patients with comorbid depression and obesity who have undergone laparoscopic sleeve gastrectomy. To our knowledge, this study will be the first randomized controlled trial attempting to use DCBT to improve the outcomes of young and middle-aged patients with comorbid depression and obesity who have undergone laparoscopic sleeve gastrectomy. A successful DCBT program would be a feasible and scalable approach to manage the general mental health status and quality of life of such patients. Chinese Clinical Trial Registry ChiCTR2500107106. Registered on 4 August 2025.