To date, the most common pharmacological treatments for dementia are cholinesterase inhibitors and N-methyl-D-aspartate receptor antagonists (antidementia medications), which are associated with a delay in the progression of the cognitive and functional symptoms. Studies of the effects of antidementia medications on neuropsychological symptoms (NPS) show varying results. Presence of NPS can also affect the amount of time caregivers spend with persons with dementia, which can affect informal costs of the condition. This project used extant data from the longitudinal, population-based Cache County Study on Memory and Aging (CCSMA) and the Dementia Progression Study (DPS), which included permanent residents aged ≥ 65 of Cache County, Utah. Linear mixed models were used to assess the association between antidementia medications with informal costs and NPS. The first study examined whether antidementia medications were associated with a decrease in informal costs. Use of antidementia medications was not significantly associated with informal costs (expβ = .79, p = .090). When restricting the sample to only the participants who were of mild dementia severity at baseline, antidementia medications were associated with a 28% decrease in informal costs (expβ = .72, p = .039). The second study evaluated whether antidementia medications were associated with a decrease in NPS. Results indicated that use of antidementia medications was associated with a 28% increase in NPS (expβ = 1.28, p < .001). However, this association was no longer significant with the inclusion of covariates, in particular, the use of psychotropic medications. Use of any psychotropic medication was significantly associated with a 30% increase in Neuropsychiatric Inventory (NPI) score. Overall, the use of antidementia medications may not significantly reduce informal costs or NPS. The use of antidementia medications may reflect patterns of use that are prompted by severity of dementia and NPS.