The goal of this study is to explore whether mitochondrial dysfunction exists in patients with chronic insomnia disorder. The main questions it aims to answer are :

• Do serum mitochondrial markers change in patients with chronic insomnia?
• Is there a relationship between serum mitochondrial markers and sleep and cognition in patients with chronic insomnia disorder? The researchers will compare serum mitochondrial marker levels among participants in the chronic insomnia group with those in the healthy group, and analyze the relationship between the markers and sleep and cognition of the participants.

Participants will:

• Complete polysomnography, the Pittsburgh Sleep Quality Index (PSQI), the Chinese-BeiJing version of the Montreal cognitive assessment (MoCA-C), the Blue Velvet Arena Test (BVAT), the Nine Box Maze Test (NBMT) to assess sleep and cognition.
• The venous blood was drawn to detect mitochondrial marker levels.

Inclusion Criteria:

• meet the diagnostic criteria of the third edition of the International Classification of Sleep Disorders,26 At the same time, meet the following requirements: ① Duration suffered form insomnia > 6 months; ② 18-60 years old; ③ Receiving education ≥ 9 years of, without any understanding and hearing impairment; ④ The Pittsburgh Sleep Quality Index (PSQI) > 7 sores, Hamilton Anxiety Scale-14 (HAMA-14) < 14 scores, The Patient Health Questionnaire-9 (PHQ-9) < 10 scores; ⑤ There was no history of any sedative and hypnotic drugs in the two weeks prior to the visit

Exclusion Criteria:

• patients during pregnancy or breastfeeding or patients who have taken sedative hypnotic drugs or any other drugs that may affect sleep, mood and cognitive function within two weeks were not eligible for the study.

Qualified and voluntary subjects were recruited from the Sleep Disorder Department of Chaohu Hospital affiliated to Anhui Medical University from October 2021 to July 2023.