Comparison of Acceptance and Commitment Therapy (ACT) and Cognitive Behavior Therapy (CBT) for Chronic Insomnia: A Pilot Randomized Controlled Trial.

"Disclosure Jung-Won Shin and Seonyeop Kim are co-first authors. The authors report no conflicts of interest in this work."

"This study was supported by a research grant from the Korean Sleep Research Society in 2020, and the National Research Foundation of Korea, South Korea (NRF) grant funded by the Korean government (No. NRF- 2020R1F1A1067882)."

"This was a single-site trial conducted at a University Medical Center, where participants were recruited between August 2020 and July 2021, and they were admitted to outpatient sleep clinics in the Medical Center due to symptoms of insomnia. The study recruited adults aged 19 years or older who met the research diagnostic criteria for chronic insomnia as defined by the International Classification of Sleep Disorders-3, and participants were diagnosed after face-to-face interviews and structured questionnaires with a neurologist (JWS) in the outpatient sleep clinic at their first visit. The following exclusion criteria were applied: (1) uncontrolled psychiatric conditions requiring immediate treatment outside the scope of the study, including an ongoing major depressive episode; (2) uncontrolled medical conditions suspected to affect sleep or requiring immediate treatment outside the scope of the study; (3) previous diagnosis or evidence of specific sleep disorders, such as restless legs syndrome, obstructive sleep apnea, or circadian rhythm sleep disorders (screened using clinical interviews and sleep questionnaires, including Sleep-50); (4) use of any sedating drugs or hypnotics for improving symptoms of insomnia; or (5) insufficient Korean language proficiency hindered their ability to complete the protocol. Written informed consent was obtained from all participants and the study received approval from the institutional review board of CHA University Medical Center (IRB approval No.: 2020–06-028). This trial has been registered with the Clinical Research Information Service (CRIS), Republic of Korea (KCT0008296). The study followed the principles of the Declaration of Helsinki."