August 20, 2025
It takes an average of three-and-a-half years after symptoms are first noticed for people with Alzheimer’s disease or other forms of dementia to get a diagnosis, according to a new analysis. Prompt diagnosis is important, because available treatments may be most effective early in the course of the disease, before damage to the brain becomes extensive. A timely diagnosis can also help patients and their families plan better for future needs and care.
For the study, researchers from University College London and other institutions analyzed data from 13 previously published studies on dementia diagnosis. The studies, from Europe, the United States, Australia, and China, involved 30,257 men and women who had been diagnosed with Alzheimer’s disease or other forms of dementia. They ranged in age from 54 to 93 when memory loss, behavior changes and other symptoms of dementia first became apparent.
The researchers found that it typically took three-and-a-half years from the time that patients or family members first reported dementia symptoms to the time they got a formal diagnosis of dementia. In younger patients, under 65, it took more than four years, on average, to get a diagnosis.
The authors further noted that many cases of Alzheimer’s disease and other forms of dementia were never formally diagnosed. Studies estimate that only 50 to 65 percent of cases are ever diagnosed in high-income countries, the authors say, with many countries having even lower diagnostic rates. The findings were published in the International Journal of Geriatric Psychiatry.
In many cases, memory loss or other symptoms are subtle or dismissed as just an ordinary sign of aging, which delays diagnosis and access to care. Patients or their families may also be reluctant or afraid to learn they have a disease like Alzheimer’s, for which treatments are limited, and therefore delay or avoid seeking help.
But getting a prompt diagnosis of dementia or mild cognitive impairment, a serious brain disorder than can be a prelude to full-blown Alzheimer’s disease, can help to optimize treatment options. Newer Alzheimer’s drugs like Leqembi and Kisunla have been approved for early-stage disease and may help to slow cognitive decline in some patients. A thorough medical workup can also help to rule out reversible causes of memory loss such as depression or anxiety, sleep disorders, vitamin deficiencies, or medication side effects.
Another benefit of early diagnosis is that it gives patients and their families extra time to plan, including financial planning as well as exploring care options for the future. Someone with Alzheimer’s can also identify family members who can serve as their representative if they become unable to speak for themselves.
“Timely diagnosis can improve access to treatments and, for some people, prolong the time living with mild dementia before symptoms worsen,” said study author Vasiliki Orgeta, from University College London’s Division of Psychiatry.
As new blood tests and other methods become available to diagnose Alzheimer’s disease, it will become easier to get a diagnosis. In addition, Dr. Orgeta said, “Public awareness campaigns can help improve understanding of early symptoms and reduce stigma, encouraging people to seek help sooner. Clinician training is critical to improve early recognition and referral, along with access to early intervention and individualized support so that people with dementia and their families can get the help they need.”
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Eric Schmidt, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
