A new study from Columbia University shows that combining a brief smell test with a short memory exam can predict cognitive decline as accurately as costly brain imaging, offering a more affordable and accessible way to assess risk for Alzheimer's disease and other forms of dementia.

The study, led by Davangere P. Devanand, MD, professor of psychiatry and neurology and director of geriatric psychiatry at the Columbia University Irving Medical Center/ New York State Psychiatric Institute, provides promising evidence that these simple tests could be useful in clinical practice when combined with appropriate expertise for diagnosing later-life cognitive decline.

The research was published online on Oct. 10 in Alzheimer's & Dementia.

"Our study highlights a practical and cost-effective approach for predicting cognitive decline and dementia, which could greatly improve access to early diagnosis," said Dr. Devanand. "By using these simple tests, health care providers can gain additional clues for identifying those at risk, providing timely interventions, and increasing participation in clinical trials."

To conduct the study, researchers analyzed data from 647 participants in the Mayo Clinic Study of Aging over an eight-year follow-up period.

The results demonstrated that combining the Brief Smell Identification Test (BSIT) and the Blessed Information Memory Concentration Test (BIMCT) was as effective in predicting cognitive decline and dementia as amyloid imaging, a widely used but expensive method.

Of the participants, 102 developed cognitive decline and 34 progressed to dementia during the study.

In primary care settings where more complex diagnostic methods may not be available, the findings suggest that smell and memory tests offer a promising approach to identifying individuals who need to be referred to a specialist.

"One of the most exciting aspects of this study is its real-world application," said Jeffrey Motter, Ph.D., co-author and assistant professor of clinical psychology (in psychiatry) at Columbia University.

"These brief, non-invasive tests could be easily implemented in primary care, allowing us to identify at-risk individuals without expensive or complex procedures. This could open the door to earlier interventions and more widespread participation in Alzheimer's prevention research."