Evidence is lacking on how treatment of comorbidities improves outcomes in patients with dementia. In this study, we evaluated temporal changes in the management of comorbidities in relation to survival rates in incident dementia over a 10-year period in Sweden. Observational cohort study. A total of 40,219 patients with recently diagnosed dementia in memory clinics from the Swedish Dementia Registry (SveDem) from 2008 to 2017. In 1-year blocks, pharmacological treatment of dementia and comorbidities in relationship to risk for fractures, major cardiovascular events (MACE), and death were analyzed using Cox models. Standardized Incidence Ratios (SIR) of death are presented. After standardization for demographics and comorbidities, the risk of fracture, MACE, and mortality decreased by 16%, 23%, and 28%, respectively, between 2008 and 2016. Each year decreased the risk of fracture by 3% (hazard ratio 0.97, 95% confidence interval 0.96–0.99), MACE by 4% (0.96, 0.95–0.97), and death by 5% (0.95, 0.93–0.97). Adjustment for changes in medication use attenuated these associations. Compared with the general population, the risk of death declined by 11%, corresponding to standardized incidence rate ratio, between 2008 and 2016. Over 10 years, a reduction in the short-term risks of fracture, MACE, and death in patients with dementia was associated with changes in drug prescribing practices. These improvements seem to be partly explained by progressive implementation of dementia diagnostic, treatment guidelines, and general management of comorbidities.