The purpose of this study is to assess the safety and efficacy of Traditional Chinese medicine (TCM) according to Yin Yang theory for treatment of chronic insomnia .

All subjects giving written informed consent. In this multicenter, controlled, prospective cohort study, the outpatient and inpatient chronic insomnia patients' baseline demographic data were collected, including age, gender, education background, and medication history. Venous blood samples were collected and sent to laboratory test for blood routine, and blood biochemistry at Baseline and Week 4. The Pittsburgh sleep quality index (PSQI) was used to assess the patients' sleep quality at baseline and week 4. Objective sleep quality data is assessed by wearing a Sleep wearable devices. The classic Morningness-Eveningness Questionnaire and wearable devices was used to assess the patients' chronotype at baseline and week 4.Subjects who visit the TCM clinic of this project received Suanzaoren Decoction and Huanglian Wendan Decoction orally twice daily for 4 weeks. Add or subtract Chinese herbal medicine according to the different clinical manifestations of each patient. Subjects from TCM clinic who had previously taken Western medicine hypnotics continued taking them, and for those who had not taken before, Western medicine hypnotics shall not be given/prescribed. Subjects who visit the Western medicine clinic of this project received Estazolam 1mg tablet orally once daily for 4 weeks. The participants will have a follow-up visit every two weeks, and the prescription would be adjusted according to the condition of illness.Cessation rate of Western medicine hypnotics was assessed at Month 6.

Inclusion Criteria:

• Outpatients or inpatients.
• It conforms to the chronic insomnia diagnosis standard of Chinese adult insomnia diagnosis and treatment guide (2017 Edition).
• Chronic insomnia patients with Yin yang imbalance and Ying Wei Disharmony Syndrome.
• Informed consent, voluntary participation in the study.

Exclusion Criteria:

• Sleep apnea syndrome leads to insomnia.
• Severe depression, suicidal tendency or having committed suicide.
• Pregnant and lactating women.
• It has serious primary heart, liver, lung, kidney, blood or serious diseases affecting its survival, such as: tumor or AIDS, SCR > 1.5n (n is the upper limit of normal value), ALT > 2n (n is the upper limit of normal value), WBC < 3.0 × 109 / L;
• Those who cannot give full informed consent due to mental disorders.
• According to the researcher's judgment, other situations that are not suitable for the group, such as the change of working environment.
• Subjects who are participating in other clinical studies.