Dementia is an umbrella term for a group of progressive conditions that lead to issues with memory loss, language, problem solving, and other thinking abilities. There are various tests that experts can perform to help diagnose the condition.

Alzheimer’s disease is the most common cause of dementia. According to the Alzheimer’s Association, more than 6 million people in the United States are living with the condition.

Although there is no cure, an early diagnosis can help individuals optimize their quality of life.

Visiting a doctor is the first step in diagnosing dementia. From there, they may refer an individual to a specialist for further testing. This is usually a neurologist but could also be a geriatric psychiatrist, neuropsychologist, or geriatrician.

Keep reading to learn more about the various tests that can help doctors diagnose dementia.

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Doctors take a person’s complete medical history, including psychiatric history and any history of cognitive and behavioral changes. They may ask them about:

  • any symptoms they are experiencing that may be affecting their life
  • any current or past medical issues
  • any prescriptions and over-the-counter medications
  • their diet, nutrition, and alcohol use

The doctor will also ask about family medical history, as dementia has a genetic component. For example, people with a biological parent or sibling with Alzheimer’s are more likely to develop the disease. The risk also increases if there is more than one first-degree relative.

Learn more about the different types of dementia here.

A physical examination will help the doctor check for any underlying health conditions that might be causing cognitive problems.

During a physical exam, the doctor may:

  • check blood pressure, temperature, and pulse
  • listen to the heart and lungs
  • perform other procedures to assess a person’s overall health
  • collect blood or urine samples for laboratory testing

Information from the physical exam and laboratory tests can help the doctor identify any health problems that could cause dementia symptoms. These may include:

To assess cognitive function, the doctor will perform a neurological exam. They may look for signs of:

They will perform tests that assess a person’s:

  • reflexes
  • coordination
  • muscle tone and strength
  • eye movement
  • speech
  • sensation

The neurological exam can help healthcare professionals rule out other possible causes of cognitive decline.

These tests assess memory, problem solving, language skills, and other cognitive abilities. Some are brief and straightforward, while others may be more complex and take more time.

A neuropsychologist often delivers comprehensive mental cognitive tests to assess a person’s executive function, judgment, attention, and language. These tests help determine if the individual is aware of their symptoms, knows the time and location, and can perform simple memory tests.

The Mini-State Exam (MMSE) test

This is a common test for dementia where the doctor asks a person a series of questions to test their everyday mental skills.

There are three versions of the test that vary by length, with a maximum score of 30. A score of 20—24 suggests someone has mild dementia. The scores drop in line with dementia severity, with a score of under 12 indicating severe dementia. The average MMSE score of an individual with Alzheimer’s drops around 2–4 points each year.

Mini-cog test

This test involves remembering and recalling common objects and drawing a clock using the correct placement of the numbers. The person must then indicate a time that a doctor specifies.

The Food and Drug Administration (FDA) has also approved the use of some computerized cognitive testing devices. Doctors may administer these computer-based tests alongside the mini-cog and MMSE tests. Using a combination of clinical and computer-based tests offers doctors a more comprehensive overview of someone’s cognitive difficulties.

Doctors are currently investigating whether certain molecules, or biomarkers, in the blood are reliable indicators of Alzheimer’s and dementia-related changes. They include proteins called tau and beta-amyloid. Beta-amyloid can accumulate atypically in people with Alzheimer’s.

Blood tests

Currently, few blood tests can aid in the diagnosis of dementia. These blood tests do not have approval from the FDA. Therefore, only specialty care doctors who consult with individuals with memory issues generally use them. Doctors do not recommend them for people without cognitive issues.

These blood tests may indicate amyloid changes in the brain or neuronal damage. However, doctors must use these tests as part of an overall diagnostic plan alongside other exams.

Cerebrospinal fluid (CSF)

Another potential biomarker is neurofilament light, which increases in the CSF of people with neurodegenerative diseases such as Alzheimer’s. The CSF may also show changes in tau and beta-amyloid proteins.

The FDA has approved a CSF test called the amyloid ratio test (Lumipulse). It allows clinicians to detect amyloid in the CSF, which may predict amyloid changes in the brain.

Certain genes may increase the risk of developing Alzheimer’s and other forms of dementia. However, health professionals generally do not recommend routine testing.

One of the genes doctors associate with Alzheimer’s is APOE e4. There is a test for this gene, but the mutation only indicates an increased risk, so it does not mean a person will develop Alzheimer’s. Therefore, genetic testing is controversial.

There are also tests for genes that cause autosomal dominant Alzheimer’s disease. This rare form of familial Alzheimer’s accounts for less than 1% of all cases, and symptoms tend to begin earlier in life. Many people prefer not to know their genetic status, but others opt for a test so they are better informed.

Testing for dementia may include using brain scans. Doctors may use the following:

These tests help rule out other conditions such as tumors, strokes, or fluid in the brain. They may also identify changes in the brain’s structure or function.

Online tests are not comprehensive enough to diagnose dementia on their own. However, they can help indicate whether someone may have cognitive problems that warrant further evaluation by a doctor.

Online cognitive tests that a person can self-administer are widely available. The Self-Administered Gerocognitive Examination is one example of a free and expert validated test. Individuals can use this tool and then take the completed test to a doctor for further discussion.

Dementia typically worsens over time, but these are some of the early warning signs:

  • memory loss that interferes with daily life
  • inability to plan
  • problem-solving issues
  • difficulty completing everyday tasks
  • confusions with times or place
  • vision problems
  • misplacing things
  • issues with judgment
  • changes in mood and personality

Learn more about dementia here.

No one test can diagnose dementia. Instead, doctors make a diagnosis following a comprehensive evaluation that may include medical history, physical examination, laboratory tests, brain imaging, and cognitive testing.

Online tests are not comprehensive enough to diagnose dementia on their own. However, they can suggest that someone has cognitive problems that warrant further evaluation.