CLOCK and Parkinson disease: This leads to broken sleep patterns and weaker, shifted melatonin release-both of which are recognized hallmarks and potential risk factors for dementia.53,54 Genetic studies further strengthen this link, identifying associations between single-nucleotide polymorphisms (SNPs) in core clock genes (e.g., CLOCK, BMAL1, PER1) and susceptibility to AD and PD.55 This genetic predisposition is further compounded by the dysregulation of melatonin secretion.