Causes, Signs & Symptoms of an ID in adults


In most cases the main cause of an Intellectual Disability (ID) can remain unknown. However, nowadays we are aware of some causes of Intellectual Disabilities.

Genetics are usually the main known cause of Intellectual Disabilities in many adults. But there are several other circumstances that lead to Intellectual Disabilities.

Which are they?

The circumstances that may lead to intellectual disabilities are the following:

  • Stroke
  • Head/brain injury.
  • Illnesses that negatively affect the brain.
  • Exposure to chemicals or toxins that harm the brain.
  • Labor difficulties or birth trauma.
  • Infections (such as meningitis).
  • Malnutrition


All the above, are the most common causes of Intellectual Disabilities. Intellectual Disabilities become apparent usually very early on. It’s common for signs of Intellectual Disabilities, in adults, to have appeared much earlier, during childhood but have been “misread” by the family – especially in rural areas.

Everyone should remember that standard intelligence tests and visits to doctor, will help determine whether someone has an Intellectual Disability or not.

Types of intellectual disabilities

There is a variety of circumstances that can cause someone to develop an Intellectual Disability (ID). It is important to understand that Intellectual Disabilities can look different from person to person. Here are some types of ID:

  • Down syndrome (usually identified in early ages).
  • Autism (usually identified in childhood).
  • Fragile X syndrome (genetic condition).
  • Fetal alcohol syndrome (exposed to alcohol while in the womb).
  • Traumatic brain injury (TBI).

Signs and symptoms

How will we identify if an adult has an Intellectual Disability?

While there are common Intellectual Disabilities, they are not the only cases for Intellectual Disabilities in adults. Many have an unknown cure. However, many individuals can live full and rich lives.

As we mentioned above, there could be different reasons that can cause someone to develop an Intellectual Disability. Because of that, it can be hard to determine the reason for any disability.

How can we recognise if someone has an Intellectual Disability? What should we notice? 

If you suspect that someone has an Intellectual Disability, you should notice the following:

  • Slow learning development.
  • Failure to meet milestones in the development.
  • Difficulty reading or speaking.
  • Failing to understand social cues.
  • Issues remembering or recalling things.
  • Inability to perform routine tasks, such as dressing oneself or using a remote.
  • Relying on nonverbal communication.
  • Difficulty regulating or expressing emotions.
  • Unable to problem solve or think logically.
  • Disordered logic.
  • Lack of curiosity.
  • Inability to understand consequences.
  • Behavior inconsistent with their age.

In all cases, a visit to a doctor is mandatory. It is really usual to “read” some behaviors as behaviors of an old person and sometimes our love makes us fragile or willfully blind.

Stay tuned and learn more about AIDA project!

Scroll al inicio