CRH and Parkinson disease: The levels of adrenocorticotropic hormone (ACTH), cortisol (CORT), serotonin (5-HT), and corticotropin-releasing factor (CRH) in the patients' serum and the scores on the Hoehn–Yahr Rating Scale and the Unified Parkinson's Disease Rating Scale (UPDRS) will all be considered among the secondary outcomes.