Increased prevalence of lifestyle risk factors or shared etiology may underlie the association between schizophrenia and the subsequent risk of dementia. We explored the association between having a spouse with schizophrenia and the risk of dementia. We found a positive relationship between having a spouse with schizophrenia and vascular dementia in individuals without a mental disorder themselves but no association between having a spouse with schizophrenia and Alzheimer's dementia. As spouses share environmental risk factors and lifestyle, this might suggest that the excess risk of dementia in probands with schizophrenia could be ascribed to the unhealthy living environment among individuals with schizophrenia.
Keywords: Dementia; Disease concordance; Environment; Schizophrenia; Spouse.