CIP2A and Parkinson disease: Similarly, for non-motor symptoms assessment, there was no significant correlation between CIP2A and MMSE scores (r = 0.1152, 95% CI − 0.2365 to 0.4401, p = 0.51), HAMD scores (r = 0.181, 95% CI − 0.2728 to 0.569, p = 0.4201), and HAMA scores (r =  − 0.1189, 95% CI − 0.5336 to 0.3418, p = 0.6077) in the PD groups.