Could a sleep aid also ease Parkinson's movement problems?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * 1\. Aged 50 years or older; * 2\. Diagnosed with idiopathic Parkinson's disease according to the Movement Disorder Society Clinical Diagnostic Criteria for Parkinson's Disease (2015), with a Hoehn \& Yahr stage of 1 to 4; * 3\. Disease duration of ≥ 2 years since diagnosis, clinically stable, and able to comply with the research assessments and interventions; * 4\. Diagnosis of insomnia disorder meeting the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), with an Insomnia Severity Index (ISI) score of ≥ 15; * 5\. Stable medication regimen for at least 4 weeks prior to the study; * 6\. Signed informed consent form, with the participant or their legal guardian able to understand and willing to participate in this study. Exclusion Criteria: * 1\. History of or diagnosis with a severe psychiatric disorder, such as depression, anxiety disorders, schizophrenia spectrum disorders, or bipolar disorder; * 2\. Presence of a clinically defined neurological disorder (assessed via self-report), including but not limited to: any condition potentially associated with increased intracranial pressure, space-occupying brain lesions, history of stroke, transient ischemic attack within the past 2 years, cerebral aneurysm, dementia, or multiple sclerosis; * 3\. Severe cognitive impairment (Mini-Mental State Examination (MMSE) score below 24) or inability to complete questionnaires independently; * 4\. Chronic obstructive pulmonary disease (COPD) or any lifelong history of sleep-related breathing disorders, such as sleep apnea; * 5\. Excessive daytime sleepiness, defined as self-reported daily daytime napping ≥ 1 hour per day on ≥ 3 days per week; * 6\. Regular caffeine consumption; * 7\. Use of any orexin receptor related medication within the past 3 months. * 8\. Previous history of cataplexy or known reduced orexin levels; * 9\. Inability to read or understand Chinese; * 10\. Use of other sleep-promoting medications within the past 3 months.