Since there is no one tool on its own that can identify dementia with 100 percent accuracy, diagnosing a person with dementia can often be a challenge. In fact, many diagnoses of dementia don’t happen until the moderate to late stages of the disease due to how difficult it can be to detect in its earliest stages.

Diagnosis can be even more challenging for those in the Intellectual and Developmental Disabilities (IDD) community. Many of the most common symptoms of dementia such as language challenges and difficulty with coordination are often things people with IDD already struggle with. This can make it all the more difficult to separate symptoms of dementia from their pre-existing symptoms.

How can I recognize if my loved one with IDD has dementia?

The most important things to look for are changes to your loved one’s usual behavior, known as their ‘baseline.’ Think of how they are on a day-to-day basis. If they’ve always struggled to remember people’s names or had difficulty completing a certain task like tying shoelaces, these aren’t necessarily signs of dementia in their case. However, if their memory has suddenly gotten noticeably worse or they’re having a hard time doing something they’ve never had problems with before, these changes in baseline can be red flags. 

However, it’s important to keep in mind that dementia is just one possible explanation. Another medical condition may cause these symptoms, as well as anxiety or depression. Make note of when the symptoms started, how frequently they occur and if there are any circumstances you’re aware of that may have heightened them, such as a major life event like moving or a stressor like a relationship conflict.

What are the symptoms of dementia when a person also has IDD?

Each person experiences dementia in different ways, so your loved one may experience one symptom and not others. That said, below are some common symptoms of dementia experienced by those who also have IDD identified by the Alzheimer’s Association. Keep in mind that for a loved one with IDD, the symptom on its own may not be the red flag, but the increase in or change to the symptom can be much more telling.

  • Inability to make decisions
  • Difficulty in recognizing familiar people or places
  • Inappropriate emotional reactions
  • Difficulty with movement, coordination, vision and hearing
  • Seizures
  • Change in previous routines
  • Inability to stay focused
  • Behavioral or personality changes
  • Refusal to engage in hobbies or things they previously enjoyed
  • Loss of appetite or unexpected weight loss
  • Skill loss

How can I get my loved one diagnosed?

Signs of dementia being written off as just another symptom of IDD can be a very real concern for caregivers of loved ones with IDD. This is known as “diagnostic overshadowing,” and can prevent a diagnosis from being made in the early to mid-stages of the disease.

Getting a diagnosis as soon as possible will give you the time you need to prepare for the future and better help your loved one, so it’s important to be an advocate for your loved one if you suspect dementia. When you visit a doctor or specialist, come prepared to describe the symptoms which most concern you and how they differ from your loved one’s previous baseline. Many people tend to minimize concerns to doctors in hopes of a better diagnosis, but now is not the time to do so. Be honest and make sure the doctor has the full picture of your loved one’s condition so they can make a more accurate diagnosis.

Dementia and IDD resources  

For additional information and support for your loved one, look into the following resources:

This article was written as a part of the Expansion of Dementia-Capable Communities within Urban and Rural Settings in Ohio using Evidence-Based and Informed Programming project, funded by the Administration for Community Living, Alzheimer’s Disease Program’s Initiative (#90ADPI0052-01-00).