Developmental disability

A **developmental disability** is a disability that starts when someone is very young, and it limits progress with the developmental milestones that mark different ages of childhood and the transition from childhood to adolescence and then to adulthood. As a result, someone with a developmental disability may learn and grow at a slower pace than other people their age.

Some examples of developmental disabilities are:

- Autism
- Attention deficit hyperactivity disorder
- Down syndrome
- Cerebral palsy
- Dyspraxia
- Learning disabilities such as dyslexia, dysgraphia, or dyscalculia
- Fragile X syndrome
- Intellectual disability
- Fetal alcohol syndrome

Developmental disabilities can make some things harder. Some people can't speak out loud. Some people need extra help learning how to read. Developmental disabilities can affect someone mentally or physically, or both. Sometimes a developmental disability can be diagnosed when someone is young. For example, if a child has trouble walking, they might be diagnosed with a developmental disability.

Sometimes developmental disability isn't diagnosed until later. For example, some people are diagnosed with autism as adults. They were still autistic as babies, but it might not have been obvious at that time.

## Causes

There are many causes for developmental disabilities. Doctors don't know most of the causes.

Many developmental disabilities are genetic. A person's genes are inherited (passed down) from both parents. Sometimes, as a fetus (unborn baby) develops, unexpected changes occur in their genes. These changes are called mutations. Certain mutations cause developmental disabilities like Down syndrome or Fragile X syndrome.

Some developmental disabilities are caused by outside conditions. For example, if a mother drinks a lot of alcohol while pregnant, this could cause the baby to have fetal alcohol syndrome. Lead poisoning or other harmful substances can also cause developmental disabilities.

### Physical disabilities

Many people with developmental disabilities also have physical issues or disabilities as well. Some issues are symptoms of the condition. For example, dyspraxia is a disability where someone has trouble with movement and coordination. Other conditions or disabilities are commonly associated with developmental disabilities. For example, people with Down syndrome are more likely to have epilepsy than someone without the condition.

### Mental health disabilities (dual diagnoses)

People with developmental disabilities are more likely to develop mental illnesses or other mental health issues than people without developmental disabilities. When someone has both a developmental disability and a mental illness, this is called a dual diagnosis. An estimated 30 to 35% of people with developmental disabilities also have a mental illness

There are a couple causes for that:

- Trauma from abuse, bullying, harassment and other incidents
- Lack of opportunities for employment, education, recreation, and other fulfilling life activities
- Genetic and biological reasons

People with developmental disabilities are more likely to develop:

- Depression
- Anxiety
- Post-Traumatic Stress Disorder

### Throughout history

Throughout history, society has considered people with developmental disabilities as "lesser" and used that justification to treat people with developmental disabilities badly. People with developmental disabilities were considered a "problem" or a "burden" that needed to be solved.

#### Ancient Era

In ancient Europe, people with developmental disabilities were considered lesser. In Greece and Rome, children with developmental disabilities were often left to die. Aristotle wrote, "_as to the exposure and rearing of children, let there be a law that no deformed child shall live_." In the medical field, Greek scholars like Hippocrates and Galen proposed that the source of disability is a problem in the brain.

In the Bible, Jesus was kind to people with disabilities and often performed "miracle cures" such as restoring a blind person's sight. In 1 Thessalonians 5:14, Paul wrote: "_comfort the feeble-minded_." Some Christians saw it as charity to care for people with developmental disabilities.

#### Institutional and Reform Eras

The Middle Ages saw the beginning of institutions for disabled people. Former places for people with leprosy were changed to house people considered deviant (badly behaved), which included people with disabilities. The Catholic Church created orphanages for abandoned babies. In England, "poor laws" created places for people to live and work. However, the conditions in all of these institutions were poor and many died.

Most societies thought that people with disabilities should be segregated (kept separate) from non-disabled people and imprisoned. In the 1800s and 1950s, institutions became common. Some hoped to educate people with developmental disabilities and others were just "warehouses" to keep people. Even though some institutions meant well, the conditions were often very poor.

Jean-Etienne Dominique Esquirol (1782-1840) provided the first classification (group) system for intellectual disability, dividing people into "idiots" and "imbeciles." Imbeciles were "_generally well formed, and their organization is nearly normal. They enjoy the use of the intellectual and affective faculties, but in less degree than the perfect man, and they can be developed only to a certain extent._" Idiots were "_Incapable of attention, idiots cannot control their senses. They hear, but do not understand; they see, but do not regard. Having no ideas, and thinking not, they have nothing to desire; therefore have no need of signs, nor of speech._" While these classifications seem to be based on intellectual capacity, it is not that simple. Anyone who could not speak would be considered an "idiot." Many people who today may not be diagnosed with an intellectual disability, could have been considered an "imbecile" or "idiot" then.

Dorothea Dix, an American reformer, petitioned Congress for better care for people with disabilities. She asked for 5 million acres to care for people with disabilities, which Congress gave. Despite her good intentions, this began the era of public institutions.