Finnish researchers find work‑performance decline can signal dementia up to 15 years before diagnosis

A Finnish study tracking 793 early‑onset dementia patients and 7,000 healthy controls over 12 years discovered that reduced work performance and income loss may appear up to 15 years before a formal diagnosis. Patients with early‑onset Alzheimer’s showed a measurable earnings drop six years prior, while those with frontotemporal dementia experienced a decline starting 11 years before diagnosis. On average, early‑onset patients earned about $13,000 less per year and lost roughly $86,000 in wages as they took extended breaks or left work earlier than peers.

The findings echo high‑profile cases such as actor Bruce Willis, whose 2022 frontotemporal dementia diagnosis ended a 44‑year career, and actor Chris Hemsworth, who learned he carries a ten‑fold increased genetic risk for Alzheimer’s and subsequently took time off to focus on family. Willis’s wife, Emma Heming Willis, said she “never in a million years” imagined he would develop the disease. Researchers stress that symptoms often dismissed as stress—forgetting appointments, difficulty concentrating, or reduced productivity—should prompt medical consultation, as early detection can slow progression.