Insomnia disorder is one of the major neuropsychiatric diseases which received more attention in recent years. Disturbances in the amino acid neurotransmitter, gama-amino butyric acid (GABA) and hyperarousal of cortex are hypothesized to contribute to the neurobiology of insomnia. Both animal experiment and clinical observation have demonstrated that acupuncture can generate treatment effect on insomnia symptom. However, the underlying mechanism remains unclear. The principal objective of this project is to use magnetic resonance spectroscopy (MRS) as well as acupuncture to provide the first in vivo characterization of cortical GABA levels between pro- and post-acupuncture treatment in individuals with chronic insomnia disorder (CID), and use resting state functional magnetic resonance imaging (fMRI) to determine whether CID patients have altered brain connectivity and network parameter changes. The investigators are also exploring the correlation between cortical GABA levels, fMRI parameter changes and abnormalities in sleep parameters and neuropsychology test in CID patients.

Three groups of subjects (CID accepted true acupuncture, CID accepted sham acupuncture and healthy) will participate in the study. All subjects will undergo a laboratory blood test, physical and neurological examination, polysomnography (PSG) and an extensive battery of neuropsychological assessments. All subjects meeting eligibility criteria for the study will complete a baseline MRS and fMRI to evaluate differences in multi-modality brain GABA and fMRI parameters between the patients and healthy. After randomized acupuncture treatment, investigators will compare brain metabolic and functional parameters to elucidate the neural mechanism of acupuncture therapy on insomnia, provide theoretical evidence from the perspective of neurotransmitters and brain network.

Inclusion Criteria:

• Clinical diagnosis of chronic insomnia disorder (CID) met the criteria of the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5)
• Subject has history of chronic insomnia (difficulty with sleep induction, awakenings during the night, early morning awakening) of at least 3 months
• Must be able to cooperate with cognitive testing and MRI scan

Exclusion Criteria:

• Known pre-existing sleep disorder other than chronic insomnia disorder
• Circadian rhythm sleep disorder determined by sleep-wake cycles of sleep (such as work time at day and night alternation)
• Severe general medical disorders of cardiovascular, endocrine, renal, or hepatic systems
• Clinical diagnosis of AD or Parkinson's neurodegenerative diseases
• Moderate or severe psychological illness
• Clinical history of stroke or other severe cerebrovascular disease
• Clinical history of malignancies disease
• Active treatment with antipsychotic medications, benzodiazepines or other hypnotic agents (i.e. Trazodone, Mirtazapine, Zolpidem, Zaleplon)
• Alcohol or drug abuse