Case‐control co‐twin study on the associations of dementia risk factors with episodic memory in nonagenarians

Several risk and protective factors of dementia are known, but the importance of genetic and environmental influences and the antecedents of cognitive functioning in 90‐year‐olds are not well known. Genetic and environmental confounding can be controlled better by using family data compared to samples of unrelated individuals. We examined dementia risk factors in 90‐year‐olds by conducting a case‐control co‐twin study on the associations of physical and psychological well‐being with episodic memory (EM).