Aim 3: (exploratory): Explore interrelationships among candidate genes, cognitive diagnostic outcomes, and proposed phenotypic components relevant to LLD. Exploratory Hypotheses: 1) COMT val158met polymorphism will be associated with CN; 2) 5-HTTPRL and APOE ε2 polymorphisms will be associated with frailty; 3) genetic variation (SNPs) in TPH2 and AGTR1 will be associated with risk factors of AD: LOD, episodic memory, hippocampal volume, and appetite loss.