Depression and Dementia are Associated, But How?

Associations between depression and subsequent dementia have been widely reported, but how these conditions are connected remains unclear. Using an Australian data-linkage system, researchers followed 4922 men, initially without clinically meaningful cognitive impairment, from 2001–2004 through June 2015 (baseline age range, 71–89).

At an average follow-up of 9 years, 18% of men received dementia diagnoses (determined by hospital codes), and 38% died dementia-free. Based on baseline hospital codes, self-reported depression histories, and a patient-completed geriatric-depression scale, adjusted risk estimates (sub-hazard ratios [SHRs]) for subsequent diagnoses of dementia were 1.3 among men who had ever been depressed and 1.5 among those with…