Serum TP concentrations in the AD, DLB, GPI, VD, and elderly patients with schizophrenia groups (all P < 0.001), as well as the serum albumin concentrations in the AD (P < 0.001), DLB (P = 0.009), GPI (P = 0.019), VD (P < 0.001), and elderly patients with schizophrenia (P < 0.001) groups were significantly lower than those of the normal elderly control group. Here, ALB is linked to Alzheimer disease.