Efficacy of Digital CBT-I Utilizing Embodied Artificial Intelligence Agent in Virtual Reality

The goal of this clinical trial is to evaluate whether a virtually embodied artificial intelligence (AI) agent delivered via VR-enhanced digital cognitive behavioral therapy for insomnia (dCBT-I) can improve insomnia outcomes and treatment adherence in adults with insomnia. The main questions it aims to answer are: \- Does VR-enhanced dCBT-I with an embodied AI agent lead to greater improvements in insomnia symptoms compared to app-based dCBT-I with an AI chatbot at post-intervention and 3-month follow-up? Researchers will compare VR-enhanced dCBT-I with an embodied AI agent to app-based dCBT-I with an AI chatbot to see if the VR-enhanced intervention results in significantly improved clinical outcomes and adherence. Participants will: * Be randomly assigned to either the VR-enhanced AI agent intervention group or the app-based AI chatbot control group * Complete a digital cognitive behavioral therapy for insomnia (dCBT-I) program with either a virtually embodied AI agent (VR-based) or a chatbot-based application * Undergo assessments at baseline, post-intervention, and 3-month follow-up

Inclusion Criteria: * Adults of Chinese ethnicity, aged between 18 and 65 years. * Presence of insomnia, as indicated by a score of 10 or higher on the ISI. * Meeting the DSM-IV-TR diagnostic criteria for insomnia disorder. The 1-month duration criterion in DSM-IV-TR rather than the 3-month criterion in DSM-V is adopted to broaden the clinical relevance of the study findings. * Willing to provide online informed consent to participate in the study. * Willing to comply with the requirements outlined in the study protocol. * Possession of a smartphone and consistent internet access for smartphone use. * Acceptance of the terms of service and privacy policies of the mobile apps used for intervention delivery. Exclusion Criteria: * A current or history of any sleep disorders other than insomnia disorder, such as narcolepsy, obstructive sleep apnea, and restless legs syndrome. * A current or history of mental retardation or neuropsychiatric disorders other than depression or anxiety or stress disorders (as they are considered treatment outcomes), including bipolar disorder, schizophrenia, and substance use disorder. * Presence of serious suicidality, demonstrated by ideation with a plan or a previous suicide attempt. * Currently receiving long-term pharmacological treatment, including sleep-promoting agents. * Currently undergoing structured psychotherapy. * A current or history of significant visual, auditory, or balance impairment. * A current or history of epilepsy * Subject who is preparing for pregnancy or pregnant * A current or history of any voice, speech, language disorders and learning difficulties. * A current or history of severe health conditions (e.g., stroke, heart attack) * Engaged in shiftwork or trans-meridian travel within the past 3 months or during the study.