IRCT20230807059073N1 IRCT 2025-12-28 Shahid Beheshti University of Medical Sciences Measuring the effect of internet-based intervention on reducing insomnia symptoms in cancer survivors ICBT-C Evaluation of the effectiveness of internet-based cognitive behavioral intervention on sleep quality and insomnia severity in cancer survivors 2026-02-20 anticipated 30 Recruiting https://irct.ir/trial/88244 interventional Randomization: Randomized, Blinding: Not blinded, Placebo: Not used, Assignment: Parallel, Purpose: Supportive, Randomization description: Participants are assigned to intervention and control groups using permuted block randomization with varying (random) block sizes (e.g., 2 and 4), generated by Random Allocation Software (RAS). Using varying block sizes ensures unpredictability and prevents selection bias. Allocation concealment is achieved using sequentially numbered, opaque, sealed envelopes. N/A Insomnia Disorder (in cancer survivors). Intervention 1: Intervention group: The intervention group receives the Internet-based Cognitive Behavioral Therapy (ICBT-I) package. This intervention involves access to a dedicated website that provides educational content (videos, text), sleep hygiene education, stimulus control techniques, sleep restriction, and cognitive restructuring in a step-by-step format over a specified period. Intervention 2: Control group: The control group is placed on a waiting list and receives no specific intervention during the study period (usual care). To adhere to ethical standards, the intervention package will be offered to this group after the completion of the study and follow-up assessments. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is There is no further information.