title: Does Schizophrenia in Offspring Increase the Risk of Developing Alzheimer's Dementia.
abstract: OBJECTIVE
  Prior studies have consistently found a higher risk of dementia in individuals with schizophrenia, but whether this is due to a common etiology between the disorders remains obscure. We wanted to elucidate this association by investigating whether schizophrenia in offspring increases the risk of Alzheimer's dementia.
  
  
  METHODS
  All individuals born between 1930 and 1953 were identified through national registers and followed from their 50th birthday until the date of Alzheimer's dementia, death or end of the study. Regressions were performed to evaluate the association between offspring with schizophrenia and Alzheimer's dementia.
  
  
  RESULTS
  Individuals with offspring with schizophrenia did not have an increased risk of Alzheimer's dementia [incidence rate ratio (IRR), 0.97; 95% CI, 0.88-1.07] compared to individuals with offspring without psychiatric contact. This finding remained stable when evaluating early-onset (IRR, 1.10; 95% CI, 0.91-1.31) and late-onset Alzheimer's dementia (IRR, 0.92; 95% CI, 0.88-1.07). Similar findings were made for vascular and unspecified dementia.
  
  
  CONCLUSIONS
  The finding of no familial coaggregation between schizophrenia and Alzheimer's dementia may suggest that no common etiology between the disorders exists. This may indicate that the excess risk of dementia in individuals with schizophrenia is a by-product of the higher rates of somatic comorbidity and adverse health risk factors among these individuals.
authors.affiliation: National Centre for Register-Based Research, Aarhus University, Aarhus, Denmark.
authors.forename: Christopher
authors.initials: C
authors.lastname: Rohde
authors.affiliation: National Centre for Register-Based Research, Aarhus University, Aarhus, Denmark; Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark; CIRRAU - Centre for Integrated Register-Based Research at Aarhus University, Aarhus, Denmark.
authors.forename: Esben
authors.initials: E
authors.lastname: Agerbo
authors.affiliation: National Centre for Register-Based Research, Aarhus University, Aarhus, Denmark; Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark.
authors.forename: Philip Rising
authors.initials: PR
authors.lastname: Nielsen
keywords: Cohort study; Dementia; Etiology; Familial coaggregation; Psychiatric disorders