The incidence of antidepressant use was almost twice as high among adults later diagnosed with Alzheimer’s disease compared with adults who were not diagnosed with the illness, according to a study of 62,104 Alzheimer’s cases and 62,104 controls.
Using data from the Medication Use Among Persons with Alzheimer’s Disease (MEDALZ) study, Arto Puranen and colleagues found that 9 years before the Alzheimer’s diagnosis, the incidence of antidepressant use was higher among the cohort that developed disease than it was among those who did not. “The reason for this remains unknown but cannot be explained by burden of psychiatric disorders,” wrote Mr. Puranen of the University of Eastern Finland, Kuopio, Finland, and his colleagues.
The study period covered 9 years before and 4 years after diagnosis of Alzheimer’s. The mean ages of antidepressant users were comparable (77.7 years for those with AD and 78.2 years for those without). Selective serotonin reuptake inhibitors were the most often initiated antidepressant in patients with and without Alzheimer’s (88% and 73%, respectively).
The researchers found the high incidence of antidepressants in future Alzheimer’s patients 9 years prior to diagnosis “somewhat surprising.” However, they noted that AD takes hold several years before a diagnosis, and that depressive symptoms often occur in this early stage.
Careful monitoring of depressive symptoms in older patients may help identify cognitive decline earlier, they added.
Find the study here (Int J Geriatr Psychiatry. 2016. doi: 10.1002/gps.4450).