In the Journals

Mental, behavioral disorders do not increase Alzheimer’s disease risk

Analysis of national data indicated modest and time-dependent associations between mental and behavioral disorders and increased risk for Alzheimer’s disease.

“Studies investigating psychiatric disorders as Alzheimer’s disease risk factors have yielded heterogeneous findings,” the researchers wrote.

To determine whether mental and behavioral disorders in general or specific mental and behavioral disorder categories increase risk for Alzheimer’s disease, researchers conducted a nationwide nested case-control study of all Finnish individuals with Alzheimer’s disease and matched controls (n = 27,948 pairs).

Overall, 6.9% of participants with Alzheimer’s disease and 6.4% of controls had a history of any mental and behavioral disorder.

Having any mental and behavioral disorder (adjusted OR = 1.07; 95% CI, 1-1.16) or depression or mood disorder (aOR = 1.17; 95% CI, 1.05-1.3) was associated with increased risk for Alzheimer’s disease within a 5-year window but not a 10-year window.

“Our nationwide nested case-control study did not detect a strong association between mental and behavioral disorders and [Alzheimer’s disease],” the researchers wrote. “Although some associations were detected with narrow time windows, they disappeared when a wider time window was applied. This suggests that some of these mental and behavioral disorders might actually have been prodromal symptoms of [Alzheimer’s disease] and thus, underlines the importance of proper differential diagnostics of [Alzheimer’s disease] and mental and behavioral disorders. In addition, these findings highlight the importance of appropriate time window in psychiatric and neuroepidemiology research.” – by Amanda Oldt

Disclosure: Tapiainen reports no relevant financial disclosures. Please see the study for a full list of relevant financial disclosures.