Dementia Patients’ Spouses Have an Increased Risk of Dementia

The Journal of the American Geriatrics Society carries an article concerning the occurrence of dementia in spouses caring for patients with dementia.  Apparently, the risk of dementia is increased in the spouses, according to this analysis.

The study was conducted in a rural community in Utah.  More than 1,220 married couples over 65 provided the data.  None had dementia at the start of the study; they were followed for 12 years.

During the follow-up period 30 cases (i.e. 60 individuals) were diagnosed with dementia in both spouses, together with 125 where only the husband, and 70 where only the wife developed it.  After adjusting for age, gender, genetic factors (the ApoE genotype), and socio-economic factors, having a spouse with dementia was linked to a 6-times higher risk of developing dementia. For men caring for a wife with dementia, the risk was 11.9 times higher, and for women with an afflicted husband the risk was 3.7 times higher.  The magnitude of the increased risk was roughly that seen with the presence of a gene variant, ApoE-4.

What’s the likely reason for this association?  The obvious factors, such as socio-economic status or a common genetic variant, were excluded in the analysis.  Intuitively, one might suggest that a shared environmental factor could be responsible.  The researchers suggest that the chronic and severe stress of caregiving might be one cause.  But why would the spouse develop dementia, rather than another stress-related condition?  Or are the emotional effects of caregiving granted far more attention (and preventive treatment) than possible cognitive changes?  Further studies should give us the answer, in time.