Model 2 LMM showed that the effects of GRS-AD and GRS-AD*GRS-PD were still significant for visuospatial score, although the effect of CSF biomarkers were not significant; that higher baseline CSF p-tau/Aβ*time was associated with a lower memory score; that lower GRS-PD and higher baseline CSF p-tau/Aβ*time were associated with lower semantic fluency score; and that lower GRS-PD*time and higher baseline CSF p-tau/Aβ*time were associated with lower frontal/executive score, whereas time and GRS-AD*time were not. This evidence concerns the gene MAPT and Parkinson disease.